The SHI slow positron beam facility with a compact cyclotron

The SHI slow positron beam facility has been constructed. A compact cyclotr on based slow positron beam production system was developed for the first t ime by Sumitomo Heavy Industries (SHI) in 1993. However, in the primary slo w positron beam facility, the length of the slow positron beam line is very long (about 25 m) and the efficiency of the slow positron beam transportat ion is not so high. In order to solve the problem, we have constructed a ne w compact cyclotron and a new slow positron beam facility next to the prima ry ones. We have named it 'The SHI Slow Positron Beam Facility.' The new fa cility is the first accelerator based 'compact' slow positron beam facility realized by using a compact cyclotron. And the new facility is the first a ccelerator based slow positron beam facility that was planned to be constru cted 'before' the accelerator construction. On the other hand, a general ac celerator based slow positron beam facility is very 'large' and was planned to be constructed 'after' the accelerator construction. The new slow posit ron beam facility has some improvements in annealing the moderator, cooling the target, transporting the beam, monitoring the beam and so on, compared with the primary facility. An intense slow positron beam has already been produced by making use of the Al-27(p,n)Si-27 reaction in the new facility. Variable-energy positron lifetime spectroscopy with a new positron pulsing system has also been arranged in the new facility. (C) 1999 Elsevier Scien ce B.V. All rights reserved.