ISOTOPE SEPARATION BY DC ARC DISCHARGE

Research Project

Project/Area Number	05680413
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	エネルギー学一般・原子力学
Research Institution	Tokyo Institute of Technology
Principal Investigator	SUZUKI Masaaki Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, Associate Professor., 原子炉工学研究所, 助教授 (70114874)
Co-Investigator(Kenkyū-buntansha)	AKATSUKA Hiroshi Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, Researc, 原子炉工学研究所, 助手 (50231808)
Project Period (FY)	1993 – 1994
Project Status	Completed (Fiscal Year 1994)
Budget Amount *help	¥1,800,000 (Direct Cost: ¥1,800,000) Fiscal Year 1994: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 1993: ¥1,300,000 (Direct Cost: ¥1,300,000)
Keywords	Isotope Separation / DC Discharge / Arc Discharge / Plasma Application
Research Abstract	When a DC are discharge between electrodes took place across a thin capillary with its pressure about 10 Torr, the eathode region became enriched in the heavy isotope, while the anode region became enriched in the light isotope. We made an apparatus to make the DC are plasma for a sufficient long time to make the experiments of the neon isotope separation. The discharge tube (capillary) is made of quartz, and contained in a pyrex-glass pipe of 13-cm i.d. On its both ends, two flanges are connected, and they hold the electrodes and the capillary. The tips of the both electrodes are made of tantalum foil tube and mounted on water-cooled copper conductor. The ends of the capillary are connected to metal chambers in the flanges, and each of them is connected to a different sampling gas chambr. We studied the separation of neon isotopes under closed-system conditions. We examined the time constant for the relaxation to an equilibrium concentration, which was found to be 60-80 minutes. We investigated the effects of the length of capillary, discharging current, and the discharging pressure, on the equilibrium concentration. Consequyently, the separation factor became larger when the pressure was lower, when the capillary was longer, and when the discharging current was larger. We derive the equation which gives the enrichment factor from the experimental parameters by modifying one of the theoretical equations proposed. The observed enrichment factor is well explained by the equation.