Progress in Understanding the Performance of IEC Devices at

the University of Wisconsin

G. L Kulcinski, J. F. Santarius, G. A. Emmert, R. L. Bonomo, E. C. Alderson, G. E. Becerra, D. R. Boris*,

L. Campbell, D. C. Donovan, B. J. Egle, L. M. Garrison,

M. K. Michalak, C. M. Schuff, and S. J. Zenobia

* Now at NRL

October 12, 200911th U.S.-Japan IEC Workshop

Overview

• Current Status of UW-IEC Laboratory.

• Progress since the Kyoto-08 meeting

• Specific Highlights

• Conclusions

2

There are Currently Four Different IEC Chambers in Operation at the University of Wisconsin

HELIOS

SIGFE

HOMER

MITE-E

2008

Progress at UW IEC Facilities Since the Kyoto Meeting

2009

10th@Kyoto

6-Gun SIGFE Upgrade

MITE-E Ready for Operation

Measured Spatial Distribution of DD Fusion Reactions

300 KV Power Supply Placed into Operation

Confirmed Negative Ions in DD Plasmas

11th@Wisconsin

2010

IEC Physics Code Upgraded

Other UW-IEC Papers at the 2009 U. S./Japan Workshop

• Dave Boris , “Negative Ions in IEC devices ”, 2:45 PM, Monday

• Rich Bonomo, “UW-Madison IEC Laboratory: Continuing Capacity Upgrades and Infrastructure Improvement”, 3:40 PM, Monday

• Brian Egle, “Advances on the Six Ion Gun Fusion Experiment”, 4:30 PM, Monday

• John Santarius , “Integral Equation Approach to Modeling IEC Devices at Moderate Pressures”, 9:25 AM, Tuesday

• David Donovan , "Spatial and Energy Profiling of D-D Fusion Reactions in an Inertial Electrostatic Confinement Fusion Device”, 9:50 AM, Tuesday

• Eric Alderson , “A Spatial Study of Negative Ion Current Densities Produced by a Variety of IEC Configurations”, 1:25 PM, Tuesday

• Sam Zenobia , “Helium-Implanted Nano-Grain Tungsten for Fusion Reactors”, 2:15 PM, Tuesday

(Lead Author/Title/Time)

UW-IEC Posters at the 2009 U. S./Japan Workshop

• 2-Gabriel Becerra, “Upgrade of an IEC Device for 3He-3He Fusion”

• 6-Matt Michalak, “Details of the Six Ion Gun Fusion Experiment”

• 9-Sam Zenobia, “The UW-IEC Experimental Materials Program”

Poster #/Lead Author/Title

Faraday trap diagnostic confirmed the presence of negative ions-D. Boris

• Magnetic filter prevents collection of source plasma, and fast electrons.

• A negatively biased grid prevents secondary e- emission from the collector plate

• 8.5 µA/cm2 of negative ion current was detected at 40 cm from the IEC cathode

Equipment is being designed and constructed that will measure the spatial distribution of negative ions from a

spherical IEC-Alderson

8

Six Ion Gun Fusion Experiment (SIGFE)- Brian Egle

9

December 2007 December 2008 September 2009

Calculated 3He-3He fusion rates-Becerra

10

The UW IEC Experiment Materials Program-Zenobia

Applications

IEC Cathodes

MFE Divertors

Facilities

Nd:Yag Laser Heating

MITE-E: Ion Beam Implant Technology

Analyses

SEM & FIB

Species Retention (NRA & NDP)

Time Of Flight (TOF) Diagnostic is an Advancement on the FIDO concept-Donovan

• TOF concept proposed by G. R. Piefer and D. R. Boris (2007) and implemented by D. R. Boris and D. C. Donovan (2008)

• 2 identical FIDO setups on opposite sides of HOMER• Direct line of sight created through both arms and center of

chamber12

Theoretical Neutral Energy Spectrum at Cathode Agrees Well with Measured Spectrum of Reacting Neutrals and Ions-

Santarius & Emmert

70 kV, 30 mA, 1.25 mTorr, rc=0.1 m, ra=0.2 m, source D+:D2+:D3

+=0.06:0.23:0.71

Chosen point of agreement

Progress Since the 2008 Kyoto Workshop

• The installation and operation of a 300 kV, 150 mA power supply for the UW chambers is complete.

• Substantial negative ion fluxes have been measured in HOMER.

• The spatial distribution of DD fusion reactions within HOMER has been made using a time-of-flight diagnostic.

Progress Since the 2008 Kyoto Workshop (Cont.)

• Fusion reactor relevant first wall materials (W, W-Re) have been irradiated in HELIOS and a new facility (MITE-E) that separates the temperature on the sample from the high voltage gradient.

• A 6 ion-gun “Hirsch like” device (SIGFE) has been constructed and operated in the 3HeCTRE chamber.

• Computer codes to the examine the parametric behavior of D-D and 3He-3He operation in UW devices have been upgraded.

Future Goals of UW IEC Program

• Understand & extend performance of the SIGFE 6 ion-gun device.

• Inject D, 3He into SIGFE at high energies to study D3He fusion.

• Demonstrate Differential Die Away (DDA) technique with DD fuel.

• Increase 3He3He fusion rates in HELIOS.

Future Goals of UW IEC Program (Cont.)

• Compare the experimental results to code predictions of the energy & spatial distribution of DD fusion events in an IEC device.

• Understand the effect of He on the morphology of tungsten IEC cathode grids.

• Measure the current densities & spatial profiles of negative ions emanating from the cathode region.

Questions?