An automated single ion hit at JAERI heavy ion microbeam to observe individual radiation damage

Microbeam scanning and a single ion hit technique have been combined to est ablish an automated beam positioning and single ion hit system at the JAERI Takasaki heavy ion microbeam system. Single ion irradiation on preset poin ts of a sample in various patterns can be performed automatically in a shor t period. The reliability of the system was demonstrated using CR-39 nuclea r track detectors. Single ion hit patterns were achieved with a positioning accuracy of 2 mu m or less. In measurement of single event transient curre nt using this system, the reduction of the pulse height by accumulation of radiation damages was observed by single ion injection to the same local ar eas. This technique showed a possibility to get some quantitative informati on about the lateral displacement of an individual radiation effect in sili con PIN photodiodes. This paper will give details of the irradiation system and present results from several experiments. (C) 1999 Elsevier Science B. V. All rights reserved.