Materials selection, qualification and manufacturing of the in-vessel divertor cryopump for JETFunded under: FP3-FUSION 11C
The JET divertor cryopump has been optimised in terms of stresses, flow stability and operation; the liquid nitrogen cooled chevron structure in particular has to fulfil conflicting requirements at cryogenic temperatures. This publication reports on the materials selection based on measurements of properties at cryogenic and elevated temperatures, and the development of an optimised thermal treatment combining solution heat treatment, brazing and precipitation hardening. It also describes the successful development of various manufacturing technologies including: (i) techniques for brazing the chosen copper alloy onto inconel and stainless steel; (ii) surface blackening of the copper alloy with plasma sprayed ceramic coatings that are vacuum compatible and able to withstand temperatures between 70 K and 1135 K; (iii) plasma spray deposition of copper onto stainless steel in order to produce an anisotropic composite material with improved thermal conductivity, high strength and high electrical resistivity for use at temperatures between 70 K and 650 K.
Bibliographic Reference: Report: JET-P(93)51 EN (1993) 11 pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 199311238 / Last updated on: 1994-11-29
Original language: en
Available languages: en