• S. Ushijima, H. Fujisawa, Y. Iwashita, H. Tongu
  Kyoto ICR, Uji, Kyoto
• M. Masuzawa, T. Tauchi
  KEK, Ibaraki

A permanent magnet quadrupole lens with continuously adjustable strength originally designed by Gluckstern was fabricated for a final focus. It consists of five PMQ discs that rotate on their axis, where odd and even numbered discs rotate oppositely but with the same absolute angle. By setting their lengths appropriately, the coupling between x and y components can be minimized. In order to reduce multipole components higher than quadrupole, we adjust positions of magnet wedge pairs. At the same time we improve differences between the magnetic center and the mechanical center of the PMQ discs by measuring harmonics of fields in magnets. In order to carry out the beam test, a high precision movable table for the lens system is also fabricated. This table can evacuate the lens system from the beam line completely without vacuum breaking, which should ease the evaluation of the system at decreased strength region.

• K. Yamada, S. Arai, Y. Chiba, H. Fujisawa, E. Ikezawa, O. Kamigaito, M. Kase, N. Sakamoto, K. Suda, Y. Watanabe
  RIKEN Nishina Center, Wako
• Y. Touchi
  SHI, Tokyo

A new linac injector, which will be exclusively used for the RIKEN RI-Beam Factory, has been constructed to increase the beam intensity of very heavy ions such as xenon and uranium. The injector system consists of a superconducting ECR ion source, RFQ linac, three DTLs, and beam transport system including strong quarupole magnets and beam bunchers. Two DTL resonators were newly designed while existing devices including the RFQ* were modified to the other resonators. Direct coupling scheme was adopted for the rf-sytems of the DTLs, where the design study was successfully perfomed by using the MWS code. This paper focuses on the design procedure of the DTLs and RFQ as well as the results of their low and high power tests.

*H. Fujisawa, Nucl. Instrum. and Methods A345 (1994) 23-42.