Development and operation of a thin foil Faraday collector as a lost ion diagnostic for high yield d-t tokamak fusion plasmas
- Colorado School of Mines, Golden, Colorado 80401 (United States)
- JET Joint Undertaking, Abingdon, Oxfordshire OX14 3EA (United Kingdom)
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States)
- Sandia National Laboratories, Albuquerque, New Mexico 87131 (United States)
We are continuing our development of a radiation-hard, charged-particle detector consisting of a series of thin parallel conducting foils as a lost ion diagnostic for high yield d-t tokamak fusion plasmas. Advantages of this detector concept include economy, ability to operate in relatively intense neutron/gamma ray radiation backgrounds and at moderately high temperatures, and a modest degree of energy resolution. A detector consisting of four parallel foils of Ni, each of thickness 2.5 {mu}m, was operated in the Joint European Torus during the recent DTE-1 experiment. During the highest yield pulses of this campaign, (16 MW), the flux of energetic alpha particles at the detector was measured to be less than about 2thinspnA/cm{sup 2}. This upper limit is significantly greater than the expected flux assuming classical losses and given the geometry of the detector. During most of the nearly 2500 pulses of the DTE-1 experiment for which the detector response has been inspected, a relatively intense (up to 200thinspnA/cm{sup 2}) flux of low energy positively charged particles was observed which appears related to the D-{alpha} photon flux at the plasma edge. Similar detector designs have been recently evaluated using monoenergetic helium ion beams from the tandem accelerator at Sandia National Laboratories. One such detector, consisting of six foils of 6 {mu}m thick Al demonstrated an energy resolution of about 7{percent} for 7 MeV alpha particles. Possible improvements to this detector concept include the fabrication of an {open_quotes}integrated circuit{close_quotes} like design consisting of alternately deposited layers of insulator and conductor. Future applications of the detector concept include first wall lost ion diagnostics for the ignition device to test engineering concepts and NSTX. {copyright} {ital 1999 American Institute of Physics.}
- OSTI ID:
- 295686
- Report Number(s):
- CONF-980605-; ISSN 0034-6748; TRN: 99:001872
- Journal Information:
- Review of Scientific Instruments, Vol. 70, Issue 1; Conference: 12. topical conference on high-temperature plasma diagnostics, Princeton, NJ (United States), 7-11 Jun 1998; Other Information: PBD: Jan 1999
- Country of Publication:
- United States
- Language:
- English
Similar Records
Evaluation of an ITER compatible, thin foil Faraday collector as a lost alpha particle diagnostic for high yield D{endash}T fusion plasmas
Application and Continued Development of Thin Faraday Collectors as a Lost Ion Diagnostic for Tokamak Fusion Plasmas