Hiroo Hasebe

Charge strippers for Radioisotope Beam Factory at RIKEN

The accelerator complex at the RIKEN Radioisotope Beam Factory accelerates heavy ions ranging from oxygen to uranium using triple stripping system to provide the beams at required charge. In many cases, the charge strippers cause problems during high-intensity beams accelerator operation. The charge stripper problem has been most significant during uranium beam acceleration because the lifetimes of the conventional carbon foils are extremely short. We conducted extensive R&D on the first stripper and found a solution using a low-Z gas stripper. We also plan to modify a second stripper operating recently with short-lifetime carbon foils. The stripper with better parameters will be needed when the beam intensity is increased by a new injector system for acceleration of uranium beam with higher charge.

Liquid Film Stripper for Intense Heavy-Ion Beams

A charge stripper system using a thin liquid film was developed for high-intensity heavy-ion beams at the RIKEN RI-beam factory. A stable free-standing film of silicone oil with a fairly large area was produced using a fast-rotating disk with a flat edge. A beam test was performed to measure the durability of the liquid film against ion beam bombardment.

Foreword of the 27th world conference of the international nuclear target

This special issue of the Journal of Radioanalytical and Nuclear Chemistry is dedicated to the 27th World Conference of the International Nuclear Target Development Society (INTDS 2014) held from August 31st to September 5th, 2014 at the National Museum of Emerging Science and Innovation (Miraikan) in Odaiba Tokyo, Japan with special emphasis on targets for accelerator-based research. INTDS 2014 was organized by the RIKEN Nishina Center for Accelerator-based Science, Saitama (Fig. 1). The series of INTDS conferences dates back to 1963 when the ‘‘First Symposium on Research Materials for Nuclear Measurements’’ was organized by the Central Bureau for Nuclear Measurements (CBNM; recently, IRMM—Institute for Reference Materials and Measurements) in Belgium. Since then, researchers involved in target preparation shared their experience and discussed related problems during biennial conferences hosted alternatively in Europe, North America and Asia (www. intds.org). The 23rd INTDS conference was held in Tsukuba, Japan in 2006. It was delightful to meet again in Japan on the occasion of the 27th International INTDS conference. Close to 80 participating scientists from 17 countries (Belgium, Canada, China, France, Germany, India, Italy, Japan, Korea, Pakistan, Poland, Romania, Russia, South Africa, Switzerland, UK, USA), met in Tokyo to present 67 scientific contributions covering the wide field of ‘‘Targets for Accelerator-based Research’’. A laboratory tour of the RIKEN RI Beam Factory was included in the scientific program to introduce the institution and laboratories. The conference comprised eleven different sessions titled ‘‘Targets and strippers for RIBF’’, ‘‘Classical accelerator targets’’, ‘‘RI beams’’, ‘‘Gas strippers’’, ‘‘Liquid strippers’’, ‘‘Production targets’’, ’’Medical and industrial applications’’, ‘‘Radioactive targets’’, ‘‘Target characterization’’, ‘‘Liquid and gas targets’’, ‘‘Radioactive targets’’, and ‘‘Laser-related targets’’. The sessions included many activities such as the discussion of exciting new developments or methods, reports on improvements of established techniques, presentation of scientific results by young scientists, and the introduction of groups and laboratories, new to the Society. The conference site, the National Museum of Emerging Science and Innovation (Miraikan) is situated right in the waterfront area of Tokyo what made it easy to socialize and discuss in varying groups. The Wednesday afternoon was dedicated to visiting Kanda Shrine to have a prayer ceremony, and then Tokyo Skytree which is the world’s highest free-standing tower. The day ended with a conference dinner in a night cruise ship on Tokyo bay. During the banquette the traditional INTDS Award of Recognition was presented to David Gilliam from NIST, USA, for his dedication to the Society. During his long membership in the INTDS he served for many years on the Board of Directors, also serving as Vice-President in 2002, and President from 2003 to 2007. In 2008 he assumed the role of Corresponding Secretary/Treasurer, holding this position to the present day. The award was handed in absentia, and the honour of accepting the award fell to colleague attending the conference. & H. Okuno okuno@riken.jp