Ion-temperature determination with a baffled Langmuir probe.

An electrostatic Langmuir probe for real-time measurements of parameters in magnetized plasma is tested in fully ionized, barium, Q-machine plasma. The small-diameter, long-length, tungsten wire sensor, i.e.

Factors influencing the commercialization of inertial fusion energy.

Managing the IFE pathway to fusion electricity will involve management of commericalization scope, schedule, cost and risk. The technology pathway to economical fusion power comprises the commercialization scope. Industry assumes commercialization risk in fielding its own pre-pilot plant research programme for this compact-fusion pathway without the benefit of a federally coordinated IFE research and development programme.

Control of current and voltage oscillations in a short dc discharge making use of external auxiliary electrode.

A dc discharge with a hot cathode is subject to current and voltage plasma oscillations, which have deleterious effects on its operation. The oscillations can be inhibited by installing an auxiliary electrode, placed outside of anode. By collecting a modest current through a small opening in anode, we show that the discharge becomes stable, in a certain pressure range.

Magnetically insulated baffled probe for real-time monitoring of equilibrium and fluctuating values of space potentials, electron and ion temperatures, and densities.

By restricting the electron-collection area of a cold Langmuir probe compared to the ion-collection area, the probe floating potential can become equal to the space potential, and thus conveniently monitored, rather than to a value shifted from the space potential by an electron-temperature-dependent offset, i.e., the case with an equal-collection-area probe.

Observation of inverse ion-cyclotron damping induced by parallel-velocity shear.

The generation of broadband multiharmonic spectra of electrostatic ion-cyclotron waves is demonstrated in a magnetized laboratory plasma in which shear in the magnetic-field-aligned (parallel) ion flow and a relative parallel electron drift are present. Shear correlates with an increased number of harmonics and a decreased electron drift speed. Wave and particle measurements indicate that cyclotron damping is reduced and even becomes negative.

Experimental verification of the shear-modified ion-acoustic instability.

The predicted shear-induced shift of the wave phase velocity, the essence of the shear-modified ion-acoustic (SMIA) instability mechanism that reduces ion Landau damping for otherwise damped ion-acoustic waves [V. Gavrishchaka et al., 80, 728 (1998)], is verified with direct measurements in a strongly magnetized laboratory plasma.

Spatiotemporal laser perturbation of competing ionization waves in a neon glow discharge.

The experimental verification of spatiotemporal periodic pulling, a specific but universal phenomenon associated with driven, nonlinear, spatiotemporal systems, is reported as part of a study characterizing the ability of dc and chopped laser light to induce periodic pulling in ionization waves propagating in a neon glow-discharge plasma. The degree to which a single-mode laser beam at a metastable transition of 6401 A (1s(5)-2p(9)) influences the discharge is found to depend on the location and magnitude of the perturbation. Cases of ac (chopping the light) and dc perturbation are presented.