Ion species control in high flux deuterium plasma beams produced by a linear plasma generator

Abstract

The ion species ratios in low energy high flux deuterium plasma beams formed in a linear plasma generator were measured by a quadrupole mass spectrometer. And the species control in the plasma generator was evaluated by changing the operational parameters like neutral pressure, arc current, and axial magnetic confinement to the plasma column. The measurements reveal that the lower pressures prefer to form more D+ ions, and the medium magnetic confinement at the higher pressures results in production of more D2+, while the stronger confinement and/or larger arc current are helpful to D2+ conversion into D3+. Therefore, the ion species can be controlled by adjusting the operational parameters of the plasma generator. With suitable adjustment, we can achieve plasma beams highly enriched with a single species of D+, D2+, or D3+, to a ratio over 80%. It has been found that the axial magnetic configuration played a significant role in the formation of D3+ within the experimental pressure range.

Temperature dependence of surface topography and deuterium retention in tungsten exposed to low-energy, high-flux D plasma

“…To generate a D plasma, D 2 gas was filled in the plasma generation section to a pressure of 1 Pa. In doing so, a plasma beam highly enriched with species of D 2 + to over 80% was obtained [9]. The bias voltage of -80 V was applied to the W sample resulting in an incident energy of 38 eV/D, taking into account the plasma potential of about -4 V measured by a Langmuir probe.…”

“…Corp., Japan) with a purity of 99.99 wt.% fully re-crystallized at 2070 K for 1 hour after cutting and polishing was used. The linear plasma generator used for delivering a plasma beam comparable to the edge plasma at ITER divertor is described elsewhere [9]. To generate a D plasma, D 2 gas was filled in the plasma generation section to a pressure of 1 Pa.…”

Surface morphology and deuterium retention in tungsten and tungsten–rhenium alloy exposed to low-energy, high flux D plasma

“…[15]. was set by the thermal contact between the sample and the cooled holder, and the temperature 2 Ductility is a mechanical property that describes the extent in which solid materials can be plastically deformed without fracture.…”

Temperature dependence of surface morphology and deuterium retention in polycrystalline ITER-grade tungsten exposed to low-energy, high-flux D plasma

“…To generate D plasma, D 2 gas was filled in the plasma generation section to a pressure of about 1 Pa. As a consequence, the plasma beam contained species of D 2 + (over 80%) and D + (less than 20%) [12]. A bias voltage of -80 V was applied to the W sample, resulting in incident energy of 76 eV for D 2 + (38 eV/D), taking into account the plasma potential of about -4 V as measured by a Langmuir probe.…”

“…The linear plasma generator (JAEA, Tokai) used for delivering a plasma beam comparable to the edge plasma at ITER divertor is described elsewhere [12]. To generate D plasma, D 2 gas was filled in the plasma generation section to a pressure of about 1 Pa. As a consequence, the plasma beam contained species of D 2 + (over 80%) and D + (less than 20%) [12].…”