Preparation of fullerenes by arc discharge between graphite anode and tungsten cathode; Effects of gas species

Otsuki, Ryusei*; Nasu, Shoichi*; Ohashi, Kentaro*; Yamamoto, Ryoichi*; Fujii, Kimio; Okubo, Keisuke*

Funtai Oyobi Fummatsu Yakin, 51(8), p.626 - 629, 2004/08

https://doi.org/10.2497/jjspm.51.626

The He, Ar and the Penning gas pressureeffects on the preparation yieldsof the fullerenes were investigated by means of the arc discharge method using graphite(PGX) anode buried in a tungsten rod and tungsten cathode for collector radii of 50mm. The maximum yield showed about 13-14 % at 67KPa in He gas. The yields in the mixtures of He and Ne gases (the Penning effect) were similar to those obtained in He gas. Weight ratios of C to (C+C) were about 20% in Ar gas, while those in He and Penning gas were about 60%. Ultra sonic vibration was effective to separate C from soot.

Production mechanism of high proton ratio plasma in a hydrogen arc discharge ion source

Morishita, Takatoshi; Inoue, Takashi; Iga, Takashi*; Watanabe, Kazuhiro; Kashiwagi, Mieko; Shimizu, Takashi; Taniguchi, Masaki; Hanada, Masaya; Imai, Tsuyoshi

JAERI-Tech 2003-007, 16 Pages, 2003/03

JAERI-Tech-2003-007.pdf:1.28MB

Recently the ion source for IFMIF (International Fusion Material Irradiation facility) achieved positive ion beams of 120 mA with the proton ratio of 90% by applying magnetic filter even in a small ion source. The mechanism of a high proton ration plasma production in such a small ion source has not been studied. Molecular ions are destroyed and the proton is produced from the dissociation of molecular ions in the filter region. Thus the proton yield is enhanced even in the small volume discharge. Using the same numerical method, the plasma production was calculated for the large ion source. The high proton ratio can be easily obtained, where the contribution of proton production by the ionization of H becomes high. From the negative ion production point of view, the negative ion beam current was numerically evaluated. The high atom flux to the plasma grid generates the large amount of negative ions rather than that by the positive ions in Cs-seeded large ion sources.

Service lives of long-life carbon stripper foils in the first three years operation of the JAERI tandem accelerator

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Nuclear Instruments and Methods in Physics Research A, 249, p.133 - 136, 1986/00

https://doi.org/10.1016/0168-9002(86)90660-1

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