Effect of magnetic filter in a volume production multicusp ion source

A study of VUV emission and the extracted electron-ion ratio in hydrogen and deuterium plasmas of a filament-driven H−/D− ion source

“…A Langmuirprobe was then used to confirm that the stronger field is required to reduce the electron temperature near the plasma electrode to $0.5 eV, favorable for the DEA process and survival of the negative ions. 27 The higher electron temperature observed in Ref. 27 across the filter field volume at certain magnetic field strength implies that the plasma potential is indeed higher in deuterium discharge.…”

“…The cross field diffusion can lead to the formation of an ion-ion plasma, 29 which is also observed in negative ion sources 33,34 and implied by the very low coextracted electron current with hydrogen observed in this study. The higher coextracted electron current with the deuterium implies lower negative ion density in the extraction region, whereas it has been observed with a Langmuir-probe 27 that the electron density at the plasma electrode could be even higher for deuterium at comparable field strength. These results are consistent with the data presented here, and altogether, they emphasize the role of diffusion in determining the extracted negative ion current and electron-ion ratio over the production of molecules at high vibrational levels.…”

“…In a recent study, 27 with a similar filament-drive ion source, it was found that optimizing the extracted current of D À requires a stronger filter field than optimizing the current of H À . A Langmuirprobe was then used to confirm that the stronger field is required to reduce the electron temperature near the plasma electrode to $0.5 eV, favorable for the DEA process and survival of the negative ions.…”

Microwave excitation of a low-energy atomic hydrogen

“…Then, ICP starts ignition of the plasma inductively induced by eddy current as increasing the input power: H-mode (electromagnetic). This mode transition from E-mode to H-mode can be observed by the jump of brightness and electron density for MHz driven RF plasma [14][15][16][17]. Moreover, a magnetized RF plasma can realize mode transition from H-mode to a W-mode (propagating wave) [17][18][19][20].…”