TFTR vacuum system considerations

Technical Report · Sat Nov 01 00:00:00 EST 1975

DOI:https://doi.org/10.2172/5425308· OSTI ID:5425308

Lange, W. J.; Gorman, J. G.; Green, D.; Sink, D. A.

The Tokamak Fusion Test Reactor (TFTR) vacuum system has been designed using conventional ultrahigh vacuum (UHV) components and technology. This report describes the rationale and motivation that went into its design. Mercury diffusion pumps were selected over other existing high vacuum pumps. A system of four pumps is designed to provide a base pressure of less than or equal to 8 x 10/sup -6/ Pa and a low impurity level within the torus. These features will be accomplished without in situ bakeout, but the system will be pre-baked before final assembly and periodically discharge cleaned during operation. Bakeout of the total vacuum system has been omitted in the initial design because it is believed that satisfactory conditions of the walls can be obtained without it. However, bakeout is being considered as a design alternative. Calculated spectra of mass to charge (M/e) ratios obtained from the residual gas analyzers (RGA's) to be used in the vacuum system forelines are presented. These spectra indicate the ability of the RGA's to monitor the tritium content of the vacuum system. The requirements for vacuum seals on TFTR are enumerated and the reasons for selecting flat copper washer seals are given. Also included is a brief summary of initial experimental studies on the Zr/Al-type getters to be used to pump hydrogen isotopes. The report concludes with a discussion of in situ bakeout, a method of reaching bakeout temperatures, and problems related to such operations.

• Research Organization: Westinghouse Electric Corp., Pittsburgh, Pa. (USA). Fusion Power Systems Dept.
• DOE Contract Number: EY-76-C-02-3073
• OSTI ID: 5425308
• Report Number(s): WFPS-TME-021; TRN: 78-002130
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
TFTR DEVICE
VACUUM SYSTEMS
PERFORMANCE
ALUMINIUM
CLEANING
GETTERS
OPERATION
SEALS
SPECIFICATIONS
VACUUM PUMPS
ZIRCONIUM
CLOSED PLASMA DEVICES
ELEMENTS
LABORATORY EQUIPMENT
METALS
PUMPS
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TRANSITION ELEMENTS
700209* - Fusion Power Plant Technology- Component Development & Materials Testing