トリスタン超高真空系用アルミ合金真空チエンバーの研究

概要

論文の詳細を見る
The TRISTAN Electron Positron Colliding Ring consists of a main ring of 30GeV (e-, e+) with a diameter of approx. 1000m, and a subordinate ring of 6-8GeV (e-, e+) with a diameter of approx. 100m for preacceleration and storage. Both rings require a pressure of approx. 10-9 Torr at Beam On and a pressure of approx. 10-10 Torr at Beam Off, respectively. Considering the effect of beam on the vacuum, the chamber is made of aluminum alloy with a high cooling efficiency because the inner walls are exposed to very powerful radiation (3kW/m (approx. 100W/cm2)). Generally, aluminum alloy with a high outgassing rate has been thought of as unsuitable for ultra-high vacuum material. A newly developed aluminum alloy produced by special extrusion, however, shows an outgassing rate in the order of 10-14 Torr l/s·cm2 due to 24-hour baking at 150°C. Also, the residual radioactivity in the aluminum new alloy is noticeably reduced, compared with stainless steel. The above-mentioned facts prove that this alloy is excellent as ultra-high vacuum material. As a result of the experiment using the aluminum alloy in all vacuum parts it is confirmed that, contrary to the conventional view, aluminum alloy is most suitable for ultra-high vacuum material and that the TRISTAN Ring in which the alloy is used can be operated with a satisfactory performance.
社団法人プラズマ・核融合学会の論文