Jack Oughton - Layman's Guide to Nuclear Fusion V1

8/8/2019 Jack Oughton - Layman's Guide to Nuclear Fusion V1

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Laymans Guide To Nuclear Fusion V1.0: Creative Commons Attribution-NonCommercial-ShareAlike 3.0

Material by Jack Oughton available for writing assignments, contact: |[email protected] |www.writing.xijindustries.com

. Contents .Part 1: Why Fusion? Humanitys Growing Resource Problem Part 2: Fusion A Primer Part 3: Fusion Energy Cycles Part 4: Fusion Confinement Devices Part 5: Public Awareness Of Fusion Part 6: Conclusion Part 7: Appendixes

But if you wanted to know what the perfect energy source is? The perfect energy source is one that doesn't take up much space, has a virtually inexhaustible supply, is safe, doesn't put any carbon into the atmosphere,doesn't leave any long lived radioactive waste, it's fusion . But there is a catch. Of course there is always acatch in these cases. Fusion is very hard to do. We've been trying for 50 years. .. And we have 30 million

years worth of fusion fuel in sea water..

Prof. Steven Cowley Director of the United Kingdom Atomic Energy Authority's CulhamLaboratory- Source: TED Talks http://www.ted.com/talks/steven_cowley_fusion_is_energy_s_future.html

Introduction:This project is intended as a primer on nuclear fusion and is written in mostly non-technical language for the non scientific reader. It is a research project on theapplications of nuclear fusion as a power source. This is a large area of science, but I

have done my best to condense the large amount of available information into aneasily understandable format.

As a research document this work is compiled from a variety of sources, adding myown commentary in the context of this work. Though much of this is my own work, Imake no assumptions or claims to any of it I have credited the authors whenever Ihave used information they have provided

I will not discuss the application of fusion in weaponry. The world has seen the effectsof this already and there is ample information on it.

This document is not intended to discuss the entire field in great detail, which is farbeyond the scope of a short document like this. It is instead a carefully arranged,ordered primer and a signpost. Ample links provide further roads for the intriguedreader to explore fusion on his own terms. There is far more coherent informationthan I could reasonably express, or fit in to the document.

On another note, I am not a fusion scientist, simply a very interested undergraduate. Ihave done my best, but have probably made mistakes, I acknowledge this.

I hope that you find this information both useful and informative. The energy shortfall

and pollution problems are huge hurdles to human progress. The realisation ofcommercially viable fusion presents a very real solution.


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Part 1.

Why fusion? Humanitys worseningresource problemIn grossly simple terms, there are two problems quickly becoming apparent that effect modern civilization.These problems are:

1) Increasing energy costs due to limited availability of fuels with finite deposits.2) Increasing pollution due to increased economic development and global energy usage

Both problems clearly derive from the our reliance upon, and the burning of fossil fuels, which are finite,cause atmospheric pollution and in some areas are unable to be obtained in quantities fully able to satisfydemand.

In 2007, the world consumed an estimated 531 exajoules of energy [one exajoule, [denoted as EJ], is 10exponential 18 joules]. This is equivalent to the energy released by detonating about 9.73 million A-bombs.Sources:EIA: www.eia.doe.gov/BP: www. bp .com/

World Energy Shortfall Predictions Note: prediction around 2050 of a beginning of a shortfall.


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Even an acceptable release of C0 2 is double the amount the world faced before fossil fuels became widely used in industry!

Modern man consumes around 35 times the amount of yearly energy of primitive, pre-agricultural man.


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World Energy Use and Reserves circa 2001 Source: WEANote: in 2001 renewables comprised less than 14% of our energy supply.

UN Predicted world growth 1950-2050. Note that the scale is logarithmic andthe population value is given in millions! - Source data calculated from:http://esa.un.org/unpp/

According to the U.S. Energy Information Administration (EIA), the demand forglobal energy is projected togrow 44% between 2005 and 2030 . This will be


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caused by a number of factors, such as continuing economic growth andincreasing populations in developing countries.- Source: http://www.eia.doe.gov/oiaf/ieo/highlights.html

This same report also stated that China is the largest consumer of the worldscoal supply, and since 2000 its coal usage has doubled. Given the countrysexpanding economy, and large coal reserves, Chinas demand for coal isexpected to remain strong. In the reference case, world coal usage grows by 2%every year, between 2005 and 2030, with coals share of the worlds total needsreaching 29% by 2030. Two of the main consumers of energy will be China andIndia, as they are both developing very quickly and have very largepopulations. In 1990 both the countries where consuming on average, 10% ofthe worlds total energy expenditure, but in2006 their combined share hadgrown to 19%. It is expected that with continued strong economic growth,

both countries will increase their energy consumption twofold, making up28% of total world consumption by 2030.

Fission reactors have been suggested as an alternative to this problem. Butnuclear fission power has its own problems. Licensing and building reactorstake a very long time. If the fuel were used directly (non-breeder reactors), thefinite Uranium sources would limit the available operation in a relative shorttime (several decades). Going to breeder reactors can greatly extend this time,breeder reactors can utilize more abundant Thorium in fission, and consumeUranium at a slower rate. However, these reactors produce Plutonium, which isvery, very dangerous. Concerns about the safety of nuclear fission reactorsinclude the possibility of radiation-releasing nuclear accidents, the problems ofradioactive waste disposal, and the possibility of contributing to nuclearweapon proliferation. Spent fuel elements contain plutonium-239. Thisplutonium could be separated chemically and diverted to nuclear weaponsproduction.


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Remaining oil reserves by source.Over 38% is unrecoverable.


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Chernobyl Nuclear Power Plant, reactor 4 site of the April 1986 disaster andalong with Three Mile Island in the USA, a significant reason why nuclearfissions reputation amongst the lay public (at least in the USA) retains anegative stain. (Yim 2003)

Decay timeline of fission biproducts.Note: the immense amounts of time taken for radioactivity to decay to 0.


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Diagram comparing radiotoxocity of materials in various fission and fusion reactors.

Note two points.

1. The extremely steep decline in fusion radiotoxicity relative to fission radiotoxicity.Fusion reactors have much shorter radioactive half lives than fission reactors

2. A fusion reactor with a vanadium alloy is no more radioactive thancoal plant ashesafter around 50 years.

Renewables

Renewable energy sources are an excellent alternative to finite and polluting fuels,being sustainable and a lot more environmentally friendly. However on average theydo not provide energy as cheaply as fission or other finite resources. Furthermore, theyare not always suitable in many locations. For example, geothermal plants can only besighted in areas where geological conditions allow for subterranean heat to beaccessed. Solar panels are not as effective in countries which receive on average, lesssunlight, and wind farms, obviously require a significant amount of wind.

It should be emphasized that all alternative methods of generation of electricity onEarth, wind energy, wave energy from the sea, solar radiation converted by solar cells,

etc, are all indirectly derived from the energy emitted by the Sun, i.e. they originate


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from solar fusion. Even the atmosphere, the rivers and the forests providing otherenergy alternatives for electric power are driven by heat and light from solar fusion.

Great efforts will be needed to achieve the sustainable energy surplus we require in

the time we have available, before other options begin to run down.

-Source: Met Office Hadley Datasets |http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/

Environmentally speaking, I believe it would be prudent to hedge our bets in regardsto climate change, as the many of the predictions brought about by climate changecould be disastrous if they turn out to be accurate. One must remember that areduction in atmospheric CO2 levels would take many yearseven if emissions weredrastically reduced today . Economically speaking; we require the economicinfrastructure in place to make up the shortfall that a combination of increasedconsumption and declining fossil stocks will present in the coming decades.

Energy is undoubtedly the food of civilization. With enough cheap and clean energy,

we can produce unlimited clean drinking water from desalinating the oceans, growalmost unlimited food in the desert, and reverse environmental damage throughterraforming. We can easily power the technological, electronic systems that are soessential in both our personal lives, and to society as a whole. With planning we canlive in a world where our needs are met, and not at the expense of the environment.The path to an infinitely abundant energy source?Nuclear Fusion.

Part 2.


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Fusion a primer on possibly the worldsmost useful energy sourceIt may almost seem too good to be true, but fusion has a number of properties that,technological challenges aside, make it the most promising energy source yet.

Plasma being channelled in a fusion torus

Fusion The Benefits

SAFE If there is an accident and the magnetic containment is breached, the reaction

immediately stops! The metallic walls of the vessel surrounding the plasma would

cool the expanding plasma in a short period, collapsing the reaction cleanly andquickly.

A fusion reactor is like a gas burner the fuel which is injected into the system isburnt off. There is very little fuel in the reaction chamber at any given moment (about1g in a volume of 1000 m3) and if the fuel supply is interrupted, the reactions onlycontinue for a few seconds. Any malfunction of the device would cause the reactor tocool and the reactions would stop.

These instabilities in the plasma act as an inherent safety mechanism. A fusion reactorcannot melt down like a conventional nuclear reactor, it simply degrades to gas

Though fusion is the main energy source of hydrogen bombs, fusion alone has never


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produced a bomb; the hydrogen bomb requires a fission- based atomic bomb to set itoff. This uncontrolled fusion reaction used in a bomb is acompletely differentmechanism to the controlled fusion which is utilized in peaceful fusion.

Day-to-day-operation of a fusion power station would not require the transport ofradio-active materials

There are no byproducts that could be adapted for military purposes.

CLEAN AND ABUNDANT No carbon emissions are generated by fusion.

The raw fuels are abundant and equally distributed around the globe. This preventsgeopolitical and economic issues such as countries gaining political advantages fromthe scarcity of the resource

It also prevents economic inequalities. Fusions raw materials are available to all.

Raw materials for hydrogen will last formillions of years. They are a type (isotope) ofhydrogen deuterium (found in seawater) and lithium (a light metal which is foundin the Earths crust and in seawater). The lithium in the fusion reactor wall producestritium (another isotope of hydrogen)

The waste product from a deuterium-tritium fusion reactor is ordinar y (and harmless)helium. There are no complicated nuclear byproducts and therefore no nuclearreprocessing, or complicated fuel cycling is required.

Although radioactive materials will be generated in the walls of a fusion power plantthey would decay with half-lives of about 10 years and the whole plant could be re-cycled within 100 years. There is no long-lasting radioactive waste to burden futuregenerations.

EFFICIENT


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The oceans offer us an effectively limitless source of Deutirium.

Fusion is a very efficient form of energy production. 1 kg of deuterium and tritiumwould supply the same amount of energy as 10 million kg of coal.

The fuel consumption of a fusion power station will be extremely low. A 1 GW fusion

plant will need about 100 kg of deuterium and 3 tons of natural lithium to operate fora whole year, generating about 7 billion kWh.

The lithium in one laptop battery plus the deuterium from half a bathtub of waterwould provide the UKs per capita electricity production for 30 years.

Source - CulhamCentre For Fusion Energy- fusion.org.uk/fusion_energy.pdf

Fusion The DrawbacksThough I argue that fusion is extremely promising, it would not be balanced for me to

leave out the shortcomings of nuclear fusion.

As an energy source, fusion has very few fundamental shortcomings. The mainproblem with fusion today is that, technologically it is still beyond our grasp. Thoughgreat advancements have been made, most expert sources believe that commerciallyviable fusion is many decades away. And at the current rate of funding, this willremain to be a problem

PROBLEM: Escalating research costsMany countries perceive fusion funding as a research risk. Essentially it is

seen to have a hugepossible payoff in the far future, and the timescalesinvolved are too long. The energy problem is pressing and we need


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results now! Other renewable energy sources compete with fusion forfinite R&D funding. Sadly, many green energy advocates have yet to catchon. Many commentators, particularly those greens who have fought long

campaigns against nuclear fission, are deeply suspicious of fusion. Theydoubt fusion will deliver and believe the money earmarked for researchwould be better spent on renewables, such as wind, wave and solarenergy. Many of these other resources are already in commercial use,which makes them perceived as a more credible source of funding.

The ITER fusion reactor was originally costed at 10bn (9bn), but the rising price ofraw materials and changes to the initial design are likely to see that bill soar, officialsconfirmed today.

The warning came as scientists gathered in Finland to unveil the first component of thereactor, which will effectively act as its exhaust pipe. The reactor is expected to takenearly 10 years to build and is scheduled to be switched on in 2018.It began as a US-Russian project in the 1980s, but has since grown to include the EU,China, India, Japan and South Korea.(Sample 2009) Ian Sample,The GuardianSOURCE - http://www.guardian.co.uk/science/2009/jan/29/nuclear-fusion-power-iter-funding

SOLUTION: CONSIDER THE ALERNATIVES!There is no real solution to this. However, there is an alternative way to consider theissue.1. Fusion may be expensive but, how expensive would it be to transfer most ofhumanity away from low-laying coastal areas, assuming that global warming raisessea levels over the next 100 years?2. Fusion should be considered aninvestment . Simple economics suggests that thegrowing scarcity of fossil fuels will result in rising prices to provide power from thesesources over time, assuming they become harder to source and extract.Extending this idea further, the raw materials of fusion; deuterium and tritium areabundant enough to be practically considered infinite. As technology improves, costsof extracting deuterium and lithium and converting them to energy should fall.

Eventually we could see fusion to be a source ofextremely cheap power: no scarcity,massively efficient energy transfer.3. Commercial fusion reactors greatly outperform other renewable energy sources.

PROBLEM: Net Energy GainIn experimental fusion reactors the main goal is to achievea net energy gain.Essentially, we want to generate more power from the fusion reactions within reactorthan we put in to start and maintain those reactions. At the moment, incredibleamounts of energy are expended to create the conditions for fusion to occur, and as ofyet, no reactor has yet produced a gain. Running a nuclear fusion reactorcosts moreenergy than it generates. At the moment, a fusion reactorexpends energy.


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SOLUTION: Continue research!Reactor energy efficiency has increased every decade since fusion researchbegan(Andreani 2000).

In fusion research, achieving afusion energy gain factor Q = 1 is calledbreakeven ,and is the current goal in fusionresearch. With every year the value of Q that weobtain climbs closer to 1.In a commercial fusion reactor, a value around Q = 20 wouldbe more suitable. Some external power will be required for things that help usregulate the plasma, such as like current drive, refueling, profile control, and burncontrol.

Encouragingly, in 1997 The JET tokamak at Culham in the UK produced 16 MW offusion power which is the current world record for fusion power.

The interior of the JET torus.

PROBLEM: Heat/ Thermal PollutionAn unusual yet still valid argument against freely available cheap energy is aphenomenon known as heat pollution . The idea is that with cheap abundant energy,most will be wasted as heat. This can have detrimental effects on marine life.

Thermal Pollutions Implications For Marine EcosystemsThermal pollution can have a great influence on the aquatic ecosystem.There are various effects on the biology of the ecosystems when heated effluentsreach the receiving waters. The species that are intolerant to warm conditions may


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disappear, while others, rare in unheated water, may thrive so that the structure of thecommunity changes. Respiration and growth rates may be changed and these mayalter the feeding rates of organisms. The reproduction period may be brought forwardand development may be speeded up. Parasites and diseases may also be affected.

An increase of temperature also means a decrease in oxygen solubility. Any reductionin the oxygen concentration of the water, particularly when organic pollution is alsopresent, may result in the loss of sensitive species.For example, in summer fish may have high metabolic rates because their bodytemperatures are elevated in the warm water. At the same time they are faced withrelatively low oxygen availability because warm water holds less dissolved oxygenthan cold water. The interaction of these factors may prove critical.

Heated water can kill animals and plants that are accustomed to living at lowertemperatures.

- Source: http://www.lenntech.com/aquatic/heat.htm#ixzz0drT24IFS

SOLUTION: Ecological SafeguardsThe technology already exists to cool water before it is returned to the ecosystem.Heat pollution isnt really a problem with effective planning. The problem is notcomplicated but may be expensive; redesign of sites which are discharging hot watermay be required. Installing the following hardware at offending sites would be aneffective solution to heat pollution:

Cooling ponds: man-made bodies of water designed for cooling by evaporation,

convection, and radiationCooling towers: which transfer waste heat to the atmosphere through evaporationand/or heat transferCogeneration : a process where waste heat is recycled for domestic and/or industrialheating purposes.


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A cooling pond inNovovoronezh, Russia . Many such sites have secondary, recreational purposes that include fishing, swimming, boating, camping and picnicking. The warmwaters are often used as a fish hatchery.

PROBLEM: Neutron Production in a DTFusion ReactionDT fusion reactions produce free neutrons moving at high speed. These fast neutronscreate radioactivity when they bombard the materials of which the fusion reactor isconstructed. Thus, while the fusion process does not produce nuclear waste directly ,the fusion reactor itself does become radioactive, and its components must bedisposed of safely when the reactor is finally shut down, after the normal life of anelectric power plant.

SOLUTION: Utilize Unreactive Materials inReactor ConstructionNeutron shielding is rather simple. Neutrons are easily shielded with 24 inches or soof water, plastic, or anything else with high levels of hydrogen to provide collisionpartners of nearly equal mass for the neutrons to collide into.

The problem with radioactive materials are not a particular hurdle. This problem canbe minimized by deliberately choosing construction materials that either produce lessradioactivity or produce radioactivity that dies away more rapidly. Such materials areestimated to lose their radioactivity within 50-100 years, as oppose to the thousandsof years required for fission waste.


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Due to its low level of radioactive activation in neutron bombardment, vanadium is a promising candidate for DT fusion reactors.

P a r t 3 .

Fusion Energy CyclesThe fusion process can occur in a number of different energy cycles. Each one fusesdifferent materials, with different quantities of matter, and releases energy in differentways.


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A graph comparing the performance of the 3 main reactions; The Deutritium-Tritiumreaction, The Deutirium-Deutrium process and the proton-Boron 11 process.

Note: A Deuterium Deuterium (DD) fusion reactor would provide limitlessenergy; it requires only water as a resource. However, even higher temperatureswould be required for a DD reaction, it is unlikely to be considered in the nearfuture.


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Helium 3 fusion ( 3He3He) though another promising aneutronic reaction, is rare on theearth. Helium 3 fusion has been proposed for confinement in both magnetic or inertial fusion reactors. This isotope of helium is thought to be common on the moon!

THE DT FUEL CYCLE

The DT Fusion reaction. The release of the neutron is the main drawback of this powercycle.

According to theLawson Criterion , the DT fuel cycle is the easiest fusion process tostart and maintain within a terrestrial reactor. It also has the highest powerproduction rate of the fusion reactions. The generated power density is about 1 W percm3.


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In simple terms, the extra neutrons on the D and T nuclei make them "larger" andless tightly bound, and the result is that the cross-section for the D-T reaction is thelargest. Also, because they are only singly-charged hydrogen isotopes, the electricalrepulsion between them is relatively small. It is relatively easy to throw them at eachother, and it is relatively easy to get them to collide and stick. Furthermore, the D-Treaction has a relatively high energy yield.(Kobres 1994)

DisadvantagesHowever, the D-T reaction has the disadvantage that it releases an energetic neutron.Neutrons can be difficult to handle, because they will "stick" to other nuclei, causingthem to become radioactive, or causing secondary reactions.

ANEUTRONIC FUSIONAneutronic fusion means fusion that does not produce neutrons as a by-product.There are several candidates for aneutronic fusion, but at current the Hydrogen andBoron 11 cycle seem to be the most credible.

As energy equation below shows - no neutrons are produced, however this cyclerequires more energy to start than the DT cycle.

p + B11 -> 3 He4 + 8.7 MeV

The pB11 cycle is the most promising candidate for aneutronic fusion.

The nuclear energy from the p-B reaction is different because it comes from theproton- triggered fission of a light element, and no neutrons are released. (Light


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elements are considered to be those with a mass number less than 56, which is themass number of iron.)

This is unusual for at least four reasons:1. Light elements more often combine or fuse to make heavier elements; they dontnormally fission to make elements that are lighter yet.2. Heavy elements such as 235U (Uranium isotope mass number 235) aretraditionally considered to be the more likely candidates for fission reactions.3. Fission reactions are normally triggered by the absorption of a neutron, not aproton.4. Fissions usually result in the emission of neutrons.

Focus Fusion refers to electricity generation using a Dense Plasma Focus (DPF)nuclear fusion generator. It uses the aneutronic hydrogen-boron fuel (pB11) cycle.

If Focus Fusion reactors are made to work, they will provide virtually unlimitedsupplies of cheap energy in an environmentally sound way - no greenhouse gases, andno radiation - because the reaction of pB11 is aneutronic.

Focus Fusion faces two main technical challenges:

It requires much higher ion temperatures and plasma density-confinementtime product than Deuterium-Tritium fuel;

and x-rays produced by the reaction reduce temperatures.

The plasma focus device consists of two cylindrical copper or berillyum electrodes

nested inside each other. The outer electrode is generally no more than 6-7 inches indiameter and a foot long. The electrodes are enclosed in a vacuum chamber with a lowpressure gas (the fuel for the reaction) filling the space between them.

Focus fusion reactors are expected to be less expensive for the same amount of power.Using this power cycle, a wheelbarrow load of the Boron inBoraxo , a brand ofAmerican hand soap would be sufficient to provide all the electrical needs of a smallcity for a year.

-Sources: http://focusfusion.org/index.php/site/article/focus_fusion_reactor/William W. Flint -

http://www.polywellnuclearfusion.com/Clean_Nuclear_Fusion/Download_Book.html

MAGNETISED TARGET FUSION /SPHEROMAK FUSION


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General Fusion's reactor design consists of 220 pistons that simultaneously ram a metalsphere. This creates a shock wave inside the sphere, so that plasma rings in the centercreate a fusion reaction.

General Fusion plans to try a relatively low-tech approach to fusion calledmagnetizedtarget fusion (MTF).

The reactor consists of a metal sphere with a diameter of three meters. Inside thesphere, a liquid mixture of lithium and lead spins to create a vortex with a verticalcavity in the centre. Then, the researchers inject two donut-shaped plasma rings calledspheromaks into the top and bottom of the vertical cavity - like "blowing smoke ringsat each other ," explains Doug Richardson, chief executive of General Fusion, theCanadian energy company that is driving the MTF project.

The last step is mainly well-timed brute mechanical force. 220 pneumaticallycontrolled pistons on the outer surface of the sphere are programmed tosimultaneously ram the surface of the sphere one time per second. This force sends anacoustic wave through the spinning liquid that becomes a shock wave when it reachesthe spheromaks in the center, triggering a fusion burst. Specifically, the plasma'shydrogen isotopes - deuterium and tritium - fuse into helium, releasing neutrons thatare trapped by the lithium and lead mixture. The neutrons cause the liquid to heat up,and the heat is extracted through a heat exchanger. Part of the resulting heat is used tomake steam to spin a turbine for power generation, while the rest goes back torecharge the pistons.

General Fusion has just started developing simulations of the project, and hopes tobuild a test reactor and demonstrate net gain within five years. If everything goesaccording to plan, they will then build a 100-megawatt prototype reactor to be


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finished five years after that, which would cost an estimated $500 million.

Source: Lisa Zyga, Physorg.com| http://www.physorg.com/news168623833.html

INERTIAL CONFINEMENT FUSION/ INERTIAL FUSION ENERGY [IFE]While magnetic confinement seeks to extend the time that ions spend close to eachother in order to facilitate fusion, the inertial confinement strategy seeks to fuse nucleiso fast that they don't have time to move apart

Directed onto a tiny deuterium-tritium pellet, the enormous energy influx evaporatesthe outer layer of the pellet, producing energetic collisions that drive part of the pellet

inward. The inner core is increased athousandfold in density and its temperature isdriven upward to the ignition point for fusion. Accomplishing this in a time interval of10^-11 to 10^-9 seconds does not allow the ions to move appreciably because of theirown inertia; hence the name inertial confinement.

Atmosphere Formation Laser beam rapidly heats the surface of the fusion target forming a surrounding plasma envelope.

Compression Fuel is compressed by the rocket-like blowoff of the hot surface material.

Ignition


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During the final part of the laser pulse, the fuel core reaches 20 times the density of lead and ignites at100,000,000 degrees Celcius.

Burn Thermonuclear burn spreads rapidly through the compressed fuel, yielding many times the input energy.

Key:Laser energy

Blowoff

Inward transported thermal energy

The National Ignition Facility (NIF) at Lawrence Livermore Laboratory is exp-erimenting with using laser beams to induce fusion. In the NIF device,192 laserbeams will focus on single point in a 10-meter-diameter target chamber called ahohlraum. A hohlraum is "a cavity whose walls are in radiative equilibrium with theradiant energy within the cavity"

A hohlraum mock up to be used on the NIF laser

Other effects like the symmetry of the implosion are also important for the ignition.

The IFE laser must operate at five to ten shots a second depending on the target yieldper shot and the desired electric output of the power plant. Currently two classes of


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laser are being considered in the United States: thekrypton-fluoride (KrF) gas laserand the diode-pumped solid state laser (DPSSL) .

Like the magnetic-confinement fusion reactor, the heat from inertial-confinementfusion will be passed to a heat exchanger to make steam for producing electricity.

- Source: Rochster University |http://www.lle.rochester.edu/02_visitors/02_grad_inertialconf.php

In the resulting conditions a temperature of more than 100 million degrees Celsiusand pressures 100 billion times the Earths atmosphere the fuel core will ignite and athermonuclear burn will quickly spread through the compressed fuel, releasing ten to100 times more energy than the amount deposited by the laser beams. Only a few NIFexperiments can be conducted in a single day because the facility's optical componentsneed time to cool down between shots.In an IFE power plant, targets will be ignited five to ten times a second!


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In direct-drive , the capsule is directly irradiated by the laser beams. Inindirect-drive , the capsule is placed inside a hohlraum; made with high-atomic-mass materialslike gold and lead with holes on the ends for beam entry.

Source: Rick Hodgin - http://www.geek.com/articles/chips/national-ignition-facility-preps-self-sustaining-fusion-tests-for-2010-20090415/

The HiPER Laser Fusion ReactorHiPER is a European ICF facility being designed to demonstrate the feasibility of laserdriven fusion as a future energy source. This is made feasible by the advent of arevolutionary approach to laser-driven fusion known as 'Fast Ignition' . HiPER willuse a unique laser configuration, currently estimated at 200kJ long pulse lasercombined with a 70kJ short pulse laser.

The HiPER Science ProgrammeIt will also enable the investigation of the science of truly extreme conditions creatingenvironments which cannot be produced elsewhere on Earth (temperatures of hundredsof millions of degrees, billion atmosphere pressures, and enormous electric and magnetic fields).

The new research programs will include the following areas Astrophysics in the laboratory Behavior of matter in truly extreme conditions Material science in the challenging warm dense regime Nuclear physics and nucleosynthesis

Atomic physics Turbulent flow at very high Mach numbers


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Relativistic particle beam studies and applications plasma physics at highenergy density

Laser plasma interaction physics Quantum vacuum studies Fundamental physics in ultra-strong electric fields.

Artists impression of the HiPER facility The project was accepted onto the European Roadmap in October 2006, with the UKagreeing to take a leadership role in January 2007.The HiPER facility is anticipated toopen towards the end of the next decade dependent on the success of thepreparatory phase project. The UK is the leading contender to host the HiPER laserfacility.Source: The Hiper project | http://www.hiper-laser.org/keyfacts/KeyFacts.asp

Part 4.

Fusion Confinement DevicesRegardless of the energy cycle of nuclear fusion we use, certain conditions are requiredto start the reaction and contain the temperamental plasma environment in which theatomic process takes place.


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Another view inside the JET torus, a tokamak design.

THE TOKAMAKThe Tokamak was first discussed in the 1950s by Igor Tamm and Andrei Sakharov inthe Soviet Union. The word Tokamak is actually an acronym derived from the Russianwords toroid-kamera-magnit-katushka , meaning the toroidal chamber andmagnetic coil. This donut-shaped configuration is principally characterized by a large

current, up to several million amps, which flows through the plasma. The plasma isheated to temperatures more than a hundred million degrees centigrade (muchhotter than the core of the sun) by high-energy particle beams or radio-frequencywaves.

The Problem and Importance of Heat In The TokamakIn an operating fusion reactor, part of the energy generated will serve to maintain theplasma temperature as fresh deuterium and tritium are introduced. However, in thestartup of a reactor, either initially or after a temporary shutdown, the plasma willhave to be heated to 100 million degrees Celsius.

In current tokamak (and other) magnetic fusion experiments, insufficient fusionenergy is produced to maintain the plasma temperature. Consequently, the devicesoperate in short pulses and the plasma must be heated afresh in every pulse.

Ohmic HeatingSince the plasma is an electrical conductor, it is possible to heat the plasma by passinga current through it; in fact, the current that generates the poloidal field also heats theplasma. This is called ohmic (or resistive) heating; it is the same kind of heating thatoccurs in an electric light bulb or in an electric heater.

Neutral-Beam InjectionNeutral-beam injection involves the introduction of high-energy (neutral) atoms into


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the ohmically -- heated, magnetically -- confined plasma. The atoms are immediatelyionized and are trapped by the magnetic field. The high-energy ions then transfer partof their energy to the plasma particles in repeated collisions, thus increasing theplasma temperature.

Radio-frequency HeatingIn radio-frequency heating, high-frequency waves are generated by oscillators outsidethe torus. If the waves have a particular frequency (or wavelength), their energy canbe transferred to the charged particles in the plasma, which in turn collide with otherplasma particles, thus increasing the temperature of the bulk plasma.

The Magnetic Field In a TokamakBecause of the electric charges carried by electrons and ions, a plasma can beconfined by a magnetic field. In the absence of a magnetic field, the charged particles

in a plasma move in straight lines and random directions. Since nothing restricts theirmotion the charged particles can strike the walls of a containing vessel, therebycooling the plasma and inhibiting fusion reactions. But in a magnetic field, theparticles are forced to follow spiral paths about the field lines. Consequently, thecharged particles in the high-temperature plasma are confined by the magnetic fieldand prevented from striking the vessel walls.

The flow in the plasma is mainly used to generate the enclosing magnetic field. Inaddition, it provides effective initial heating of the plasma. The flow in the plasma isnormally induced by atransformer coil.

This simplified diagram of a tokamak describes what part each component plays inconfining plasma.


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In order to minimize particle losses caused from leaking along the magnetic field lines,the chamber is bent, which also bends the magnetic field lines. This creates thedistinctive torus shape also known as a toroidal pinch . However, the curvature of themagnetic field lines introduces new problems. Strong externally produced toroidalmagnetic fields are necessary to stabilize the plasma. These are generated by thesolenoidal magnet

The solenoid works by passing a current through an electromagnet wrapped, one turnafter the other, along the full length of the tube. It reduces the kinking problem in theplasma by adding an external source of magnetic field that "stiffens" the plasmacolumn.

A solenoid is a 3 dimensional coil which creates the magnetic field that envelopes thetorus.

A tokamak consists mainly of a toroidal tube big enough to hold the plasma that servesas fuel; a solenoidal magnet wrapped around the tube; and a transformer to drive acurrent in the plasma.


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Diagram showing how particles are trapped within the cross section of plasmaconstrained within a tokamak.

The Energy Generation Process Within The Tokamak The fusion reactor heats a stream of deuterium and tritium fuel to form high-

temperature plasma. It squeezes the plasma so that fusion can take place. The lithium blankets outside the plasma reaction chamber absorb high-energy

neutrons from the fusion reaction to make (breed) more tritium fuel. Theblankets will also get heated by the neutrons.

The heat will be transferred by a water-cooling loop to a heat exchanger tomake steam.

The steam will drive electrical turbines to produce electricity. The steam will be condensed back into water to absorb more heat from the

reactor in the heat exchanger.

Source: Princton Plasma Physics Laboratory | http://www.pppl.gov/fusion_basics/

At this time, of all the fusion projects, tokamak confinement is getting the mostfunding and the most media attention. There are 2 major new tokamak projects underconstruction, ITER in Europe and SST-1 in India. Both are designed to showcasecurrent advancements in magnetic confinement technology to the world, and toprovide the environment to research the next phase of tokamak technology.

THE POLYWELL/ BUSSARD FUSIONREACTOR


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Robert W. Bussard (August 11, 1928 October 6, 2007) was an American physicist whoworked primarily in nuclear fusion energy research, and who pioneered the polywellconcept.

The name polywell is a portmanteau of "polyhedron" and "potential well." ThePolywell is spherical instead of the donut shape of the Tokamak. The polywell methodof achieving fusion has often been referred to as the long shot to fusion and sadly,has been treated this way by the fusion community at large

As a fusion source, polywell researchers compete with tokamak derived technologyfor funding. And in the funding battle, the polywell is definitely losing, However in2009 a R&D contract worth $2 million a year from the US Navy was issued, whobelieve the polywell may be a useful power source for ships. This is promising, andmany polywell advocates have stated that positive results can be seen with a fraction

of the funding expended on Tokamak technology (which is a good thing because itlooks like thats what they will get!).

Source: Federal Business Opportunities.gov |https://www.fbo.gov/index?s=opportunity&mode=form&id=fc9fd44171017393510d46e2f8154296&tab=core&_cview=0&cck=1&au=&ck=

The Polywell community is a small but vocal open source collective of scientificenthusiasts and independent researchers.

Confinement Within The PolywellThe Polywell uses inertial electrostatic confinement (IEC) to create the conditionsfor fusion.

When all six electromagnets within the polywell are energized, the magnetic fieldsmeld into a nearly perfect sphere. Electrons are injected into the sphere to create asuperdense core of highly negative charge. Given enough electrons, the electrical fieldcan be made strong enough to induce fusion in selected particles. Positively chargedprotons and boron-11 ions are injected into the sphere and are quickly acceleratedinto the centre of the electron ball by its high negative charge. Protons and boron ionsthat overshoot the centre are pulled back with an oscillatory action of a thousand or

more cycles.Source: R. Colin Johnson | EE Timeshttp://www.eetimes.com/showArticle.jhtml?articleID=199703602


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The current, third-generation prototype uses six doughnut-shaped electromagnets tocreate a cube in which to confine the fusion reactions in a strong magnetic field. Theoriginal prototype operated in air and was just centimetres in diameter; the currentdesign operates in a vacuum chamber and measures roughly a cubic yard.

A 2D representation of the magnetic fields operating in a polywell. The coils trapelectrons and keep them in a very small, tightly packed group called a potential well.This well attracts and accelerates the Hydrogen and Boron nuclei. When they collide, the

nuclear reaction is triggered. If there is a system failure, the polywell simply loses itsmagnetic field and the process stops.


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ConclusionIt is evident that there are a great many different possibilities for fusion; in both thechoice of fuel cycle and confinement method used. Though now over 50 years old, the field is still very young. A great deal of emerging technologies look promising within fusion. Advances in other areas such as materials technology, could be a boon to theefforts of fusion researchers looking to create more efficient reactors. Similarly,disruptive technology such as the polywell and the plethora of projects lumped under theterm cold fusion could have payoffs, though the odds of this are not considered certain.

It appears that within the fusion community, current preference is towards the DT cycle,magnetically confined in a tokamak environment. This is obvious in the amounts of

money being spent on in Europe on the ITER project, although the USA is activelyresearching a variety of inertial confinement technologies in tandem with their owntokamak efforts. With advancements in future we may be looking at aneutronic fusion,though the road to commercial fusion is still some decades off.

The next section addresses public awareness and opinion of fusion, with data gathered from Europe and the USA.

Part 5.

Public awareness of fusion - Getting TheMessage Out Obviously, informed public and political awareness of nuclear fusion will be anextremely important factor in ensuring that fusion gets the attention it deserves. To beviable as an energy source, fusion must be understood, at least at some level, by thelay public who would one day reap its benefits.

Policymakers in energy must better understand what the fusion is, its economicimplications, and long term performance predictions. Educators and thought leaderssuch as teachers need to be given a clear understanding of the subject so that themessage is communicated properly by these vocal, credible sections of thepopulation.

Furthermore, it is important to educate the public on the distinctions between fusionand fission, especially as the definitionnuclear (especially thermonuclear) has anegative association with weaponry, which is unavoidable.

Finally, the obvious benefits of fusion must be communicated in a compelling, butimpartial and factual manner. I believe that encouraging public support and indeed,approval of fusion could help contribute to maintaining political pressure that ensures

fusion gets the economic support that it needs to become a reality.


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However, it is clear that competition for public mindshare is extremely tough. In thistime of mass media the amount of information the average person is exposed to isgreater than ever before. The fusion message has to contend with popular culture,constant marketing, and the concerns of normal day to day life; a great many globaland personal issues take up the average persons attention and time. Fusion is simplynot a priority for most people. This is understandable perhaps in the context of a lowawareness of the extent of the energy problem facing us in the coming decades.

Worse still, certain anti nuclear pressure groups approach fusion in the samecombative manner they have reserved for fission. For example, a consortium of Frenchpressure groups Sortir du Nucleaire (Get Out of Nuclear Energy),claimed that ITERwas a hazard because scientists did not yet know how to manipulate the high-energydeuterium and tritium hydrogen isotopes used in the fusion process.- Source: Deustch Welle - http://www.dwworld.de/dw/article/0,,1631650,00.html

In a report entitled Public Information in European Fusion Energy Research: Methodsand Challen ges , released by specialists working at fusion policy and research institutionsaround the EU, the opinions and awareness of the public in the EU towards fusion wheremeasured. The following social groups where identified as communication targets. Eachrequires a different outreach strategy and message.

Note: PI: Public information

Decision makers: due to direct link between the EU energy policy and the Europeanfusion research this group needs to be informed on both European and national levels aboutthe mission progress. The group consists of judicious, motivated, busy people. Media: as a key intermediate to pro-active communication with general public, media(TV, radio, newspapers, journals) deserve high priority PI, namely personal relations. Infusion, media relations are established, as a rule, on national levels. Schools & Universities: Teachers act as efficient intermediates to young people whowill probably decide about the industrial future of fusion. Even before, fusion R&D willneed a supply of new determined experts. Notice that fusion has relatively sparseprofessional links to Universities compared to other major research projects. Interested Public: Although fusion cannot hope for a major pro-active influence of general public, any of those who are interested and request information must feel free toobtain it, hence the passive PI must be very broad and highly responsive. Industry: Nowadays, the main topics in fusion research have expanded from basic

plasma physics towards more technological tasks, e.g. to material research, which calls fordirect involvement of different industries including their R&D. PI activities have to followthese developments and promote the opportunities. Fusion Community: Due to international dimension of the research it is vital to

foster good relations among fusion centres, calling for broad communications. Scientific Community: support from the influential category of other scientists canbe expected only if fusion community manages to inform them properly about the fusionresearch, its mission, results and strategy, as well as about joint interests. Source: http://www.iop.org/Jet/fulltext/EFDP05027.pdf

Findings: The reports findings on the public awareness of nuclear fusion wherenot very promising.


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For the general public the challenge of producing energy from nuclear fusion isquite abstract

It turns out that the level of education and social background tend to play a majorrole in awareness of nuclear fusion as future energy source.

The European public is badly informed about nuclear fusion research in the EU(~3% informed)

As far as energy-related research in the EU is concerned, nuclear fusion appears tobe at the third position on the priority list of those areas where people would likethe EU to do more, with 21% of support, well far behind renewable energy sourcesfor instance (69%).

There are significant concerns regarding the capability of nuclear fusion power tomeet the public safety and environmental requirements: almost 35% believe itwont be safe (!) , will produce long-term nuclear waste and will contribute to globalwarming.

These negative opinions are remarkable namely in relation to very low publicawareness of fusion, which contradiction can be clearly ascribed to the prejudicesassociated with the tag nuclear.

Nuclear fusion is also viewed as the second most efficient potential energy source(22%) and

It is believed (59%) that it needs much more research to confirm its potential.

The report made the following conclusions on designing aneffective communication strategy:

Clear messages : Key messages need to be simple and easy to find. Moreover, thecommunication has to be comprehensible and adapted to the target group, avoidingspecialized terminology without compromising on the message contents. The requirementsfor reliable translations and interpreters call for considerable involvement of individualAssociations in this respect.

Empathy : The form in which information is presented (including its emotionalimpacts) needs to be thoroughly appreciated. In particular, application of professionalgraphics has to be encouraged. Use of illustrations, photographs and videos beyondtechnical documentation should become routine

Division of responsibilities : In the new era of fusion, with many different worldcultures working together on extraordinarily broad technological projects like ITER, it willbe beyond capacity of scientists alone to assume all aspects of communication.Implementation of these three recommendations will put strain namely on internal communication , for scientists - they may feel that the above efforts are not a high priorityactivity. Anyway, in near future this will represent just one of many similar challengesfor fusion scientists , who will find themselves among industrial engineers, nuclearregulators, managers from different countries etc.

A highly professional communication team, combined with good communicationtraining for a sufficient number of managers, scientists and engineers , can actuallyrelieve many of these strains while concentrating on the primordial objective, theimprovement of public understanding of fusion.


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PANS (Public Awareness Of Nuclear Science)

The PANS was a prototype Public Information society, which has formed theframework for much of the more organized communication efforts now being made infusion.

The objective of PANS (Public Awareness of Nuclear Science) was to establish aEuropean-wide network for communicating information on positive achievements,techniques and diverse applications of nuclear physics to the general public.

The network comprises a group of about 23 nuclear scientists from all over Europe. Anumber of specific activities were developed, aiming at: Secondary school pupils and teachers The general public Opinion- and decision-makers, government and administrations

The projects leading achievement was the science communication book Nucleus - ATrip into the Heart of Matter published in 2001 (Canopus and John HopkinsUniversity Press in the US).

Many of the original collaborators went on to create a web-based sciencecommunication system (webSCS), which carries factual and topical information aboutthe various uses of nuclear science.

Source:http://ec.europa.eu/research/infocentre/article_en.cfm?id=/research/star/index_en.cfm?p=03_main&item=Energy&artid=1900


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American organizations are also using the internet for educational outreach.

EFDA (European Fusion DevelopmentAgreement)

In 1999, the European Fusion Development Agreement (EFDA) was created to providea framework between European fusion research institutions and the EuropeanCommission to strengthen their coordination and collaboration, and to participate incollective activities.

Between 1999 and 2007 EFDA was responsible for the exploitation of the JointEuropean Torus, the coordination and support of fusion-related research &development activities carried out by the Associations and by European Industry and

coordination of the European contribution to large scale international collaborations,such as the ITER-project.


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To reach its objectives, EFDA carries out the following group of activities: Collective use of JET, the worlds largest fusion experiment, which is located

near Oxford (United Kingdom).

Training and carrier development of researchers, promoting links touniversities and carrying out support actions for the benefit of the fusionprogramme

Reinforced coordination of fusion physics and technology research anddevelopment in EU laboratories

-Source: European Fusion Development Agreement |http://www.efda.org/about_efda/what_is_efda.htm

Conclusion: In Europe, there are a number of public outreach organizations attempting to informthe public about fusion (specifically though magnetic confinement). The EFDA worksas something of an umbrella organization and is developing a series of very effectivecommunicational tools on its website, which it is encouraging teachers and othereducators to make use of. There is a well-informed academic and amateur fusioncommunity with excellent internal, trans-national communication links. However,European public understanding of fusion is terrible; many are unaware of its properdefinition, and the nuclear stigma has remained. Some groups are even opposed to it,thinking research budgets better spent elsewhere!

Main concerns in the public perception of fusion are as followed.

High costs; Uncertainty of payoff from R&D investments; The feasibility of the technology; The visibility of the results; The need to set financial limits on R&D expenditure.

Generally speaking, the lay public seems to be more interested in technologies closerto their lives, such as health or environment related. They pay little attention and are

not aware of the wider social and political dimensions of the associated R&Dprogramme.

ITER is without a doubt, our main opportunity to bring public awareness tofusion. (Prades Lpez et al. 2008). The entire process should be orchestrated with asmuch media furor as possible, making use of all the modern tools of communicationthe internet offers, such as social media and blogging. As the fusion community isextremely technologically savvy, co-coordinating this sort of effort should not beparticularly hard, as we are already seeing organizations such as JET maintaining theirown YouTube channels and proactively communicating with the public. Via online andoffline outreach.


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In contrast with the past, the proponents of nuclear fusion are to some extentattempting to come to grips with the social circumstances. Until now they have takenthe optimistic view that if they simply built a nuclear fusion reactor, society wouldaccept it. Now they are sensing the need to make an effort to gain the acceptance ofsociety. Even greater vigilance will be necessary in future. - (Tadahiro Katsuta, CNIC,Japan)

Expert InterviewsIn researching fusion I thought it would be best to obtain opinions from people better informed than me. Below are two interviews I conducted withinternationally recognised experts on the subject.

Chris Warrick (Culham, UK) is a member of the Public Relations teamat the UKAEA Culham Science Centre. After graduating with a degree in

physics from the University of Wales, Chris joined UKAEA at Culham in


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1990 working as an experimental physicist on various fusion devicesuntil 2001. He was particularly involved with plasma microwave heatingsystems and plasma radiation measurement devices. Since 2001, Chrishas been a member of the Public Relations team with particular responsibility for education and public outreach

When are we looking at the first commercially operated fusion plant? Easy question to begin with! If we assume 10 years to build ITER, and time then to get the resultsto enable the design of the first demonstration power station and then 5-10 years to build this first demo power station, we are looking at 25-30 years. For widespread commercial power from fusion- probably 40-50 years.

What method of confinement is most likely to prevail in commercial fusion?

Here at Culham, the JET and MAST tokamak devices employ magnetic confinement of the fusion plasma. There are parallel research streams into laser induced fusion - fusion of tiny fuel pellets by implosion with laser beams. It is fair to say, that in terms of scalability to fusion power stations, themagnetic confinement research is probably closer to economically viable power.

Could a child born today be seeing 'free' energy in his/her lifetime? Fusion would never profess to offer free energy. Modelling predictions suggest fusion will beeconomically competitive with other forms of generation - but it will never be free. Neither will any other generating method.

Is 'cold' fusion believed to be scientifically feasible?

No is the quickest answer. There is no firm evidence that neutrons observed in cold fusionexperiments are actually generated from fusion. There is clearly interesting physics going on here -but this is almost certainly not fusion.

What is the best way we have for obtaining naturally occurring elemental hydrogen?

We require two forms (or isotopes) of hydrogen to make magnetic fusion here on earth. These areDeuterium and Tritium. Deuterium is easily obtained from water - all water has traces of Deuterium- about one in every 8000 water molecules. Tritium is very rare - so we are going to need togenerate this ourselves from a fusion power station. It is envisaged that the neutrons we will

produce from the fusion reaction will react with a surrounding blanket of Lithium - and make the

Tritium we will need. Hence, we will use up Lithium to make the Tritium we need. Lithium is a very common element - so we have abundant fuel reserves.

How many fusion plants would we need to supply the energy needs of the planet?

It is expected that fusion power plants will produce 1-2 GW of electricity - about the same as amodern fossil fuel or fission power station will produce. This about enough electricity for 2-3 million

people - so for the UK - about 30 fusion power stations would be enough for all our electricity needs. However, we would never argue that fusion should generate all electricity - there should bea balanced portfolio with other sources (renewables, fission etc).

How aware would you say the public are of nuclear fusion?


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Probably not enough. We strive very hard here - through public and schools outreach programmesand through media coverage - to increase the public's knowledge of fusion - and its potential as afuture source of energy. This is not always easy - and one reason is how long it will take to becommercially available.

What are the most effective ways of educating them?

See above. Media is the way to get the message out to millions of people - when we had somecoverage on BBC Horizon last year - that created a lot of interest.

Are there any possible disaster scenarios that could result from misuse of a fusion reaction?

No! The plasma inside one of our machines - although incredibly hot - 100s of millions of degrees C - is very small in mass (fractions of a gramme). If we push the plasma in any way (increase itsmass too much, lose its confining magnetic field) it will become unstable, strike the wall of thecontainer, cool rapidly and extinguish. This inherent feature if the plasma - that it will stop itself

if pushed away from its natural stability limits - ensures that an internally driven accident isimpossible to conceive.

Are there any other hypothetical power sources that could surpass fusion in our far future?

In a sense, I could say "maybe - but they have not been discovered yet". My own view is that thethree large scale electricity generating options that can make a big contribution in the future arefusion, solar (much potential here but tend to be uneconomic at present) and new generationfission. I would like to see a world where these three are pushed as hard as possible .


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Tadahiro Katsuta (Tokyo, Japan) has a PhD in plasma physics from Hiroshima University (1997). He is currently a Research Associate at the University of Tokyo. From 1999-2005 heresearched the economics of nuclear power relative to other sources of electrical power, as ananalyst at the Citizens Nuclear Information Centre in Tokyo.

Apr. 10th, 2010

*When are we looking at the first commercially operated fusion plant?*

In my understanding, thermonuclear fusion commercial reactor stands little chance of realization.According to the project of International Thermonuclear Fusion Experimental Reactor (ITER), fusionexperiment will begin in 2018 and operation period is expected to last 20 years. Following DEMOreactor is planed to put into the grid as early as 2040. However, nobody knows physics of thermonuclear fusion plasma and how to control it in the large facility. Based on my experience on nuclearfusion experiment, the hurdle is very high. It must be set the project back. Even if the physics isrealized, nuclear fusion method confronts to other commercial plants which have economic benefit. Inaddition to this, it is doubtful if any country needs such large amount of electricity.

*What method of confinement is most likely to prevail in commercial fusion?*

One of the most important requirements for commercial reactor is a stable operation. Otherwiseelectric companies and customers do not accept the installation. It is difficult that the continuousoperation of thermo nuclear fusion reaction by the magnetic confinement system. On the other hand,laser implosion system will be operated with the pulse drive. Such a large pulse driving system seemsto me unstable. Furthermore, if the technology becomes regulated in terms of nuclear nonproliferation,the introduction speed will slow down.

*Could a child born today be seeing 'free' energy in his/her lifetime?*

Children may realize solar power is the source of real 'free' energy.

*Is 'cold' fusion believed to be scientifically feasible?*

There is big difference between scientific and commercial feasibilities. Scientifically it has a potentialbut may not become a commercial big power supply.

*What is the best way we have for obtaining naturally occurring elemental hydrogen?*

We can get hydrogen by the electrolysis using renewable energy.

*How many fusion plants would we need to supply the energy needs of the planet?*

You can get total electrical power plant capacity when you divide the world electricity demand by acapacity of one nuclear fusion reactor. However, we have to consider the daily load curve and netsystem energy demand. Since it is too difficult to control the output of nuclear fusion reactor, it may beonly used for the base load. Nuclear fusion commercial reactor has difficulties to find a position as baseload power source because of existence of other safe and cheap supplies.

*How aware would you say the public are of nuclear fusion? *

I have no idea.


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*What are the most effective ways of educating them?*

The education of historical survey of science, technology and society that don't contain value judgments

*Are there any possible disaster scenarios that could result from misuse of a fusion reaction?*

If the energy use succeeds, it brings unnecessary electricity demand and radioactive waste managementproblem. In addition to these, it cause nuclear proliferation problem about H-bomb.

*Are there any other hypothetical power sources that could surpass fusion in our far future?*

Hydrogen energy created by renewable energies

Part 6.

ConclusionIt seems a clich, but for decades we have been just decades away fromcommercially applied fusion . In spite of this, fusionhas advanced in leaps andbounds. Though we have not yet seen any energy gains, the ongoing trend is of our

reactors moving closer to breakeven point. The main problem is the time that it hastaken to do this. Most people agree that we are going to see breakeven, but when is thepoint of contention. Most media sources are quoting a commercial start date ofatleast 2040.

However , the timescale to fusion powercould be accelerated with increasedfunding . Overall research spend on fusion is tiny less than 0.1% of the total energymarket worldwide. This is astonishingly small compared to what a large hi-tech orautomotive firm would spend on research (e.g Toshiba, Ford). ITERs expectedlifetime cost is less than the amount being spent on the London Olympics.source Culham Centre For Nuclear Fusion


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Diagram showing advancements in fusion technology performance compared withMoores Law and Particle Energy Accelerators.Note : Fusion performance (quantified by the triple product of theLawson Criterion -density, temperature and energy confinement time ) doubles every 1.8 years , at a slightlyhigher rate than Moores law. Considering the commercial and societal implications ofMoores law, once fusion becomes commercially viable, technological acceleration at thisrate could have a huge effect on society. For example, transistor advancement over thelast 15 years has seen the computer industry move at amazing speed . This suggests thatthis kind of exponential growth in fusion would result in a similar scenario.

Research in magnetic confinement fusion energy over the past 50 years has madetremendous progress with the Lawson parameter (nET) in magnetic fusion devicesincreasing by 10 million to within a factor of 10 of that needed for large scale fusionpower production.The next major step in magnetic confinement fusion is to be taken by ITER with theproduction of 500MW of fusion power for 400s.

Similarly, inertial confinement fusion has made impressive progress with the increasein laser driver power by 1 million, and the completion of a major facility, NIF, aimed toproduce ignition of small DT pellets and 2040 MJ of energy per pulse.

The overall highlights can be summarized:(Meade 2010): A strong scientific basis has been established for proceeding to the next stage, fusionenergy production, in the development of magnetic and inertial fusion.

Diagnostics and plasma technology (auxiliary plasma heating, current drive, pellet


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Diagram detailing past and predicted milestones in DT fusion research. Note the Qvalue for the cyan line which represents the JET test in 1997


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ITER (International ThermonuclearExperimental Reactor)

Vacuum vessel - holds the plasma and keeps the reaction chamber in a vacuum Neutral beam injector (ion cyclotron system) - injects particle beams from the accelerator into the

plasma to help heat the plasma to critical temperature Magnetic field coils (poloidal, toroidal) - super-conducting magnets that confine, shape and contain

the plasma using magnetic fields Transformers/Central solenoid - supply electricity to the magnetic field coils Cooling equipment (crostat, cryopump) - cools the magnets Blanket modules - made of lithium; absorb heat and high-energy neutrons from the fusion reaction Divertors - exhaust the helium products of the fusion reaction

ITER Main Parameters

Total Fusion Power (MW) 500


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Machine Height (m) 26Machine Diameter (m) 29Plasma Volume (m 3) 837

In Latin, Iter translates toThe Way. The ITER project is now seen asthe way to fusion,and is the next big step for magnetic confinement.

ITER is a tokamak fusion experimental reactor with superconducting magnetsand other systems that will enable the facility of generating 500 megawatts offusion power continuously for at least400 seconds! Its plasma volume will beclose to the size of future commercial reactors.

ITER is the worlds biggest energy research project. It is an example ofinternational scientific collaboration on an unprecedented scale that willprovide the link between plasma physics, engineering and future commercialfusion-based power plants.

The reactor is expected to take 10 years to build with completion scheduled for2018. ITER is designed to produce approximately 500 MW of fusion powersustained for up to 1,000 seconds (compared to JET's peak of 16 MW for lessthan a second)

ITER will demonstrate and refine key technologies, as well as generate tentimes more power than is required to produce and heat the initial hydrogen-tritium plasma.

The Seven international Parties that are co-operating to develop ITER are:China, EU, India, Japan, Russia, South Korea, and the United States. Thenegotiations take place under the auspices of theInternational AtomicEnergy Agency (IAEA).


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The ITER site is located in the south of France in Cadarache, not quite one hour to thenorth of Marseille.

Source: www.iter.org | ITER Organization

Note: http://www.iter.org/mach/Pages/Tokamak.aspx provides a more detailed andinteractive description of the components and workings within ITER.


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ITER will be constructed from many separate parts produced from many contractors. Its production schedule is a meticulously planned and co ordinated international effort.

ITERs predicted performance as compared to previous reactors. Note how far away it is from the rest of the reactors; The scale is logarithmic!


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ITERs predicted energy output will dwarf any previous fusion project.

Part 7: Appendixes

APPENDIX I: SCIENTIFIC INDEXi. What is a fusion reaction?


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Fusing elements releases enormous amounts of energy

Nuclear fusion is the process by which multiple atomic nuclei join together to form asingle heavier nucleus. It is accompanied bythe release or absorption of energy. Atshort distances the attractive nuclear force is stronger than the repulsive electrostaticforce. As such, the main technical difficulty for fusion is getting the nuclei close enoughto fuse.

The Sun can sustain its fusion reactions in part because it is so large that heat isconducted away slowly. To create a practical fusion reactor, we must compensate forsize by using good insulation to prevent rapid heat conduction. When do nuclear fusion reactions occur in a plasma? They can only occur when thetemperature is very high, many millions of degrees. The reason is that the repulsionwhich always exists between the positive electric charges of colliding nuclei has to beovercome by attractive nuclear forces. This can only happen when nuclei with highmutual velocity come within the grasp of the strong but short-range (1013 cm)nuclear forces, which occurs only for enormously high plasma temperatures about200 million degrees for deuterium-tritium reactions.

We can characterize the fusion power (the rate of heat production) in terms of theplasma pressure, since higher pressure allows more plasma density, and more densitymeans more fusion power We characterize the effectiveness of the magnetic insulation in terms of the energyconfinement time, which is simply the time that would be required for the plasma tocool off if all heating ceased(by convention, it is the time required for the temperatureto drop to about one-third its original value). We can characterize the fusion power(the rate of heat production) in terms of the plasma pressure, since higher pressureallows more plasma density, and more density means more fusion power The pressure rule says that the more current we have, the higher the plasma pressure


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we can achieve. The limit on the pressure is simply proportional to the square of themagnetic field strength. Doubling the field allows four times the pressure . While it is possible to take any two nuclei and get them to fuse, it is easiest to get lighternuclei to fuse

Documents

Jack Oughton - Layman's Guide to Nuclear Fusion V1