Radioactive targets for nuclear accelerator experiments

Abstract

The quality of a nuclear accelerator target is assessed in terms of its purity, mechanical strength, thickness uniformity and microstructure. High vacuum thin film condensation is the preferred production method, because it results in microscopically smooth targets of high purity. Special variants of this technique are used in our hot laboratory to prepare radioactive targets of good macroscopic and microscopic homogeneity while keeping the consumption of isotopic material on a low level. A particular type of carbon backing provides excellent mechanical strength to the targets. New equipment including modern production plants as well as glove boxes and hot cell facilities permits to maintain the service for a long period. In nuclear physics experiments with radioactive targets problems may arise from a possible contamination of the beam line or other equipment. A few protective measures to overcome these difficulties are mentioned.