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Title: Negative-ion-based neutral beams for fusion

Conference ·
OSTI ID:5577298

To maximize the usefulness of an engineering test reactor (e.g., ITER, TIBER), it is highly desirable that it operate under steady-state conditions. The most attractive option for maintaining the circulating current needed in the center of the plasma is the injection of powerful beams of neutral deuterium atoms. The beam simultaneously heats the plasma. At the energies required, in excess of 500 keV, such beams can be made by accelerating D/sup -/ ions and then removing the electron. Sources are being developed that generate the D/sup -/ ions in the volume of a specially constructed plasma discharge, without the addition of cesium. These sources must operate with minimum gas flow, to avoid stripping the D/sup -/ beam, and with minimum electron output. We are designing at LBL highly efficient electrostatic accelerators that combine electric strong-focusing with dc acceleration and offer the possibility of varying the beam energy at constant current while minimizing breakdown. Some form of rf acceleration may also be required. To minimize irradiation of the ion sources and accelerators, the D/sup -/ beam can be transported through a maze in the neutron shielding. The D/sup -/ ions can be converted to neutrals in a gas or plasma target, but advances in laser and mirror technology may make possible very efficient photodetachment systems by the time an ETR becomes operational. 9 refs., 4 figs.

Research Organization:
Lawrence Berkeley Lab., CA (USA); Lawrence Livermore National Lab., CA (USA); Negion, Inc., Hayward, CA (USA)
DOE Contract Number:
AC03-76SF00098
OSTI ID:
5577298
Report Number(s):
LBL-23528; CONF-871007-74; ON: DE88003852
Resource Relation:
Conference: 12. symposium on fusion engineering, Monterey, CA, USA, 12 Oct 1987; Other Information: Paper copy only, copy does not permit microfiche production
Country of Publication:
United States
Language:
English