Focusing high-energy heavy ion microbeam system at the JAEA AVF cyclotron

Oikawa, Masakazu*; Sato, Takahiro; Sakai, Takuro; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Kurashima, Satoshi; Okumura, Susumu; Fukuda, Mitsuhiro*; Yokota, Wataru; Kamiya, Tomihiro

A high-energy heavy ion microbeam system has been developed in an ion accelerator facility, TIARA of JAEA Takasaki. This was the first trial to focus heavy ion beams with an energy range of a few tens MeV/n from an AVF cyclotron accelerator in the world. The focusing system equipped with a quadruplet quadrupole magnet lens, multi beam collimators and beam scanners has been optimized following almost the same way as that of previously developed microbeam system in TIARA. However the ion beams from the cyclotron accelerator has a larger energy variation E/E and also has a larger beam current instability I/I than those of electro-static machine in general. We had to overcome these biggest problems in microbeam forming. This paper will outline the new focusing system we have developed in TIARA, and show the results of 1 m resolution by secondary electron mapping method and of single ion hit experiment for the track detectors and semiconductor test devices.