Miniature Proton Accelerator Development at Siemens by

Timothy HughesCorporate Technology

Siemens AG

A Compact Proton AcceleratorAn Industrial Perspective


Siemens AG


Siemens AG

How much does a neutron cost to produce?

We need 10x neutrons per second

End User Perspective


Siemens AG

CapitalCosts

EnergyCosts

Reliability

• Service Costs• Penalty clauses• Customer dissatisfaction• Lost reputation

• Running Costs

• Infrastructure size• Return on investment

Cost of Neutron Production


Siemens AG

• Introduction to Neutron Spallation Drivers : LINAC

• Commercial Considerations of a Spallation Driver

• Proposal for a Spallation Driver

• Accelerator Activities

A Compact Proton Accelerator : Outline


Siemens AG







Siemens AG

Spallation is the most energy efficient neutron production route

Why Spallation?


Siemens AG

High IntensityProton Beam

Neutron Spallation

Target

ApplicationUsers

Spallation Neutron Production


Siemens AG

RF ConverterHeat

RF PowerProton Beam

Wallplug

Cavity LossesHeat

Target LossesHeat

NeutronsTarget

Waste heat recovery may significantly increase overall efficiency

Accelerator Based Neutron Production


Siemens AG

( )

−⋅+= 012.010

20),(10V

UAAUY

JM Carpenter, “Pulsed Spallation Sources for Slow Ne utron Scattering” NIM 145 (1977) 91

Yield Y – neutrons per proton (n/p) as function of particle energy U and target atomic number A

Spallation Process Efficiency


Siemens AG

Spallation Neutron Source (SNS)

Ion Source RFQ Alvarez DTL

State of the art high power LINAC

CH Cavity


Siemens AG

UILZ

UP beamRF ⋅+

⋅=

2

Losses in the accelerator

Beam power

Spallation Driver : LINAC Energy Balance


Siemens AG







Siemens AG

• There is an optimum at surprisingly low energies (~ 400MV)

• Large beam currents improve efficiency

• Longer accelerators generally have incrementally higher efficiency

Energy – 500MeVZ – 35MΩΩΩΩ/m

Length – 100mZ – 35MΩΩΩΩ/m

Energy – 500MeVZ – 35MΩΩΩΩ/m

The energy cost of a neutron : J/neutron


Siemens AG

1018 neutrons/secApplication Need

Hygiene Factors Compact – 100m

Space Charge – 200mA pulsed beamKilpatrick Limit – 5MV/m E fieldPeak Pulse RF Power – 1GW

200mA pulsed beam100m lengthZ – 35MΩΩΩΩ/m

Optimum Energy – 500MeV

1018 neutrons/sec @ 500MeV = 20mA CW 10% duty cycle

1018 neutrons/sec @ 1.64 x 10 -11 J/neutron with ηηηηRF – 75% 21MW

Physics Limits

Cost Optimise for End Energy

Duty Cycle Definition

Calculate Energy Useage

• 100m long LINAC• 500MeV end energy• 10MW beam power • 50% wallplug efficiency

Energy Cost @ 0.04 $kWh – 8.4M€ per annum

Energy Costs


Siemens AG

1018 neutrons/secApplication Need

Hygiene Factors Compact – 100m

Space Charge – 200mA pulsed beamKilpatrick Limit – 5MV/m E fieldPeak Pulse RF Power – 1GW

200mA pulsed beam100m lengthZ – 35MΩΩΩΩ/m

Optimum Energy – 500MeV

1018 neutrons/sec @ 500MeV = 20mA CW 10% duty cycle

1018 neutrons/sec @ 1.64 x 10 -11 J/neutron with ηηηηRF – 75% 21MW

Physics Limits

Cost Optimise for End Energy

Duty Cycle Definition

Calculate Energy Useage

• 100m long LINAC• 500MeV end energy• 10MW beam power • 50% wallplug efficiency

Energy Cost @ 0.04 $kWh – 8.4M€ per annum

Energy Costs

Technology FocusAreas


Siemens AG

cryofrontRFaccintotal CCCCCC ++++=Cin = tunnel (13k€/m)Cacc = accelerating structure (125k€/m)Crf = RF (see grapth)Cfront= front end fixed cost (5M€)

60 cents/W

10 cents/W

1 cents/W

Commercial Perspective : Capital Costs

~ 40M€ for 1018 neutrons/sec

IFRF costs 10 cents per W


Siemens AG

60 cents/W

10 cents/W

1 cents/W

Capital Costs




IFRF costs 1 cent per W



Siemens AG



60 cents/W

10 cents/W

1 cents/W


IFRF costs 1 cent per W

RF Technology Focus

Capital Costs



Siemens AG

Reliability


Siemens AG

Reliability

Technology Focus

Front EndRF Power

Target Design


Siemens AG







Siemens AG

IS

FunnelIS

RFQ

IS

Funnel

IS

RFQ

Funnel DTL

IS

FunnelIS

RFQ

IS

FunnelIS

RFQ

IS

Funnel

IS

RFQ

Funnel DTL 1H – DTL 1H – DTL 1H – DTL 1H – DTL 1H – DTL 1H – DTL

5m, 2MeV 10m, 50MeV 100m, 500MeV

200mA5% DC500MeV

Control System

Low Energy“Defence in Depth”

Mid to High Energy“Adaptive Self Healing Array”

1018 neutrons/sec40M€ capital cost8M€ energy costs99.99% uptime

Spallation Driver Proposal


Siemens AG

(Ai,φi)………………………………………………… (An,φn)

Control System

• Self healing array of accelerating substructures

• Each cavity individually controlled (phase, amplitude, frequency)

• Control System dynamically redistributes according to fault modes

Array of independent cells

Solid State Direct Drive TM

RF Sources

Optimized parameter set

Adaptive Control system

Mid and High Energy Section


Siemens AG

100mA beam

100mA beam

200mA beamFunnel DTL

• Multiple layers of redundancy

• Pre-acceleration before DTL injection mitigates space charge

Low Energy Section


Siemens AG







Siemens AG

IS

FunnelIS

RFQ

IS

Funnel

IS

RFQ

Funnel DTL

IS

FunnelIS

RFQ

IS

FunnelIS

RFQ

IS

Funnel

IS

RFQ

Funnel DTL 1H – DTL 1H – DTL 1H – DTL 1H – DTL 1H – DTL 1H – DTL

5m, 2MeV 10m, 50MeV 100m, 500MeV

200mA5% DC500MeV

Control System

Low Energy“Defence in Depth”

Mid to High Energy“Adaptive Self Healing Array”

40M€ capital cost8M€ energy costs99.99% uptime

High CurrentIon Sources

High CurrentRFQ

Funneling

RF PowerCavity Design

Control System

GOAL

Accelerator Activities


Siemens AG

Circumferentialslit

Power combiner

(a (b

IsolationCavity

Solid-state RF Modules

Current Flow

Solid-state RF Modules

Circumferential slit

Power combiner

• Distributed independent RF sources enable Ultra High Power

• Independent control of each cavity

• No external RF source, waveguide or mode coupler

• Distributed topology enables Robust Design

RF Power: Solid State Direct Drive™


Siemens AG

n- Drift region

n+ n+

4H n+ Substrat

GateSource Source

pp+p+

DrainVDS [V]

I D[A

]

UGS=0 V

UGS=-12 VUGS=-14 V

UGS=2 V

UGS=4 V

UGS=6 V

UGS=8 V

UGS=10 V

UGS=-16 V2mm

n- Drift region

n+ n+

4H n+ Substrat

GateSource Source

pp+p+

Drain

n- Drift region

n+ n+

4H n+ Substrat

GateSource Source

pp+p+

DrainVDS [V]

I D[A

]

UGS=0 V

UGS=-12 VUGS=-14 V

UGS=2 V

UGS=4 V

UGS=6 V

UGS=8 V

UGS=10 V

UGS=-16 V

VDS [V]

I D[A

]

UGS=0 V

UGS=-12 VUGS=-14 V

UGS=2 V

UGS=4 V

UGS=6 V

UGS=8 V

UGS=10 V

UGS=-16 V2mm2mm

• SiC is intrinsically 10x faster than Silicon• Significantly enhanced power compared to Si.• Radiation hard• Hyperfast body diode survives reflected RF power• Large positive Rdson temperature coefficient

Silicon CarbidevJFET

RF Power: Solid State Direct Drive™


Siemens AG

[1] O Heid, T Hughes IPAC 2010[2] O Heid, T Hughes LINAC 2010[3] O Heid, T Hughes HB2010[4] M Hergt et al, PP Conf 2010

1 MW RF power test cavity

20kW RF power module – SiC solid state

First Results Summer 2010 [1,2,3,4]

Solid State Direct Drive™


Siemens AG

• Cost – 10 cents/Watt

• Efficiency – 80% wall plug - RF power conversion

• Reliability – redundant, gracefully degrading system

Solid State Direct Drive™


Siemens AG

– SICED, SiCrystal, INFINEON: Radiation-hard ultra fast high power switches

– MIT Boston, FIAS Frankfurt, Univ of Huddersfield : Advanced materials

– Rossendorf Dresden, Dreebit Dresden, IAP Frankfurt : Advanced ion sources

– IAP Frankfurt, BINP Novosobirsk, MEPHI Moscow, FNAL Illinois, LBNL California, JFZ Juelich, Univ Oxford: Accelerator Physics

– MIT Boston, CT PP: Advanced control systems

THANK YOU

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Miniature Proton Accelerator Development at Siemens by