Design and test of a large plasma torch for environmental recycling

A 2.5-inch inductive plasma torch has been tested with up to 600 kW rf power and with argon, nitrogen, and oxygen gases. A complete power balance is obtained from electrical, thermal, and radiation measurements. These data indicate that torch efficiencies of up to 30% are obtained with molecular gases, while efficiencies around 15% are obtained with argon. The efficiencies obtained with molecular gases almost triple earlier torch efficiencies and confirm substantially the predictions of a torch model developed during a previous CRADA. Torch efficiencies of up to 50% could be obtained in future tests with an improved rf power supply, with steam gas, and with larger torch dimensions. Future applications of the Plasma Energy Recycle and Conversion (PERC) process could include the high explosives of DOE`s nuclear weapons, chemical and biological remediation, and the treatment and volume reduction of radioactive mixed waste

Onset and saturation of ion heating by odd-parity rotating-magnetic-fields in a field-reversed configuration

Heating of figure-8 ions by odd-parity rotating magnetic fields ($RMF_o$) applied to an elongated field-reversed configuration (FRC) is investigated. The largest energy gain occurs at resonances ($s \equiv \omega_R/ \omega$) of the $RMF_o$ frequency, $\omega_R$, with the figure-8 orbital frequency, $\omega$, and is proportional to $s^2$ for $s-even$ resonances and to $s$ for $s-odd$ resonances. The threshold for the transition from regular to stochastic orbits explains both the onset and saturation of heating. The FRC magnetic geometry lowers the threshold for heating below that in the tokamak by an order of magnitude.Comment: 4 page, 3 figure

Measurement of loss of DT fusion products using scintillator detectors in TFTR

A poloidal array of MeV ion loss probes previously used to measure DD fusion product loss has been upgraded to measure the loss of alpha particles from DT plasmas in TFTR. The following improvements to the system have been made in preparation for the use of tritium in TFTR: (1) relocation of detectors to a neutronshielded enclosure in the basement to reduce neutron-induced background signals; (2) replacement of ZnS:Cu (P31) scintillators in the probes with the Y{sub 3}Al{sub 5}0{sub 12}:Ce(P46) variety to minimize damage and assure linearity at the fluxes anticipated from DT plasmas; and (3) shielding of the fiber optic bundles which carry the fight from the probes to the detectors to reduce neutron- and gamma-induced light within them. In addition to the above preparations, the probes have been absolutely calibrated for alpha particles by using the Van de Graaf accelerator at Los Alamos National Laboratory. Alpha particle losses from DT plasmas have been observed, and losses at the detector 901 below the midplane are consistent with first orbit loss

Parameters of a possible FRC adiabatic compression experiment

An experiment is described that would address the following research goals for field-reversed configurations (FRC). (a) Test FRC stability with a number of ion gyroradii relative to the plasma radius substantially greater than in present experiments. (b) Increase the electron temperature sufficiently to test the physics of electron energy confinement and of trapped-flux losses. (c) Improve confinement while remaining in a density regime (n less than or equal to 5 x 10/sup 15/ cm/sup -3/) most likely to be relevant to fusion power production