Status of the ISOL-based radioactive ion beam facility at JAERI, Tokai

放射性核種ビーム(RNB)加速実験装置の現状

市川 進一

Ichikawa, Shinichi

旧日本原子力研究所・東海研究所と高エネルギー加速器研究機構・素粒子原子核研究所との共同研究で、2001年からタンデム加速器施設に構築を進めてきた放射性核種ビーム(RNB)加速実験装置は2005年3月に施設検査に合格するとともにRNBの加速に成功した。本報告では、加速器のインジェクターとして用いるオンライン同位体分離器(ISOL)に設置したRNB用イオン源,ISOLから供給された一価イオンビームを加速に最適な価数に増倍する装置(チャージ・ブリーダー),線型加速器群(SCRFQとIH)等の現状とRNB加速実験装置の将来計画について報告する。また、2005年11月から開始された共同利用の実験課題と実験の予備的な結果についても述べる。

In accordance with the JAERI (Japan Atomic Energy Research Institute)-KEK (High Energy Accelerator Research Organization) collaborative research project, an ISOL-based radioactive ion beam facility, TRIAC (Tokai Radioactive Ion Accelerator Complex), has been constructed at JAERI, Tokai. This facility consists of an Isotope Separator On-line (JAERI-ISOL) connected to the JAERI tandem accelerator, a charge-breeding 18 GHz ECR (CB-ECRIS) and split-coaxial RFQ and interdigital-H type linacs. Radioactive singly-charged ions from the JAERI-ISOL are bred to A/q 7 in the CB-ECRIS and then multi-charged ions are accelerated with the linac-complex from 2 keV/u to the energy between 0.1 to 1.1 MeV/u. So far, various kinds of neutron-rich radioactive nuclei produced in proton-induced fission of uranium have been ionized using the FEBIAD type ion source and mass-separated by the JAERI-ISOL. The charge-breeding efficiency of the CB-ECRIS was measured for stable Ar, Kr and Xe isotopes in a series of experiments. At March 2005, we successfully accelerated Xe produced in the proton-induced fission of uranium. The charge state of the accelerated Xe was 20+ bred in-flight by the CB-ECRIS and acceleration energy of 1.1 MeV/u was achieved. In this conference, we will report the status of the TRIAC facility including the performance of the ISOL ion-source and the CB-ECRIS system as well as the future plan of this facility.