LINAC2012 - List of Authors (Yamada, K.)

Paper

Title

Page

Commissioning of a New Injector for the RIKEN RI-Beam Factory

125

N. Sakamoto, M. Fujimaki, H. Hasebe, Y. Higurashi, O. Kamigaito, H. Okuno, K. Suda, T. Watanabe, K. Yamada
RIKEN Nishina Center, Wako, Japan
R. Koyama
SHI Accelerator Service Ltd., Tokyo, Japan

A new injector for the RIKEN RI-Beam Factory (RIBF) has been fully commissioned since October 2011. The injector accelerates ions of m/q=6.8 up to 670 keV/u. In order to save the cost and space, a direct coupling scheme was adopted for rf coupling between the cavity and amplifier, based on an elaborate design with the Microwave Studio code. It has worked out very stably in these three months, making the uranium beam intensity higher by one order of magnitude. Moreover, it is now possible to operate the RIBF and GARIS facility for the super-heavy element synthesis independently.

Slides MO3A02 [19.503 MB]

TUPB073

Design and Simulation of a Test Model for a Tri-Spoke Cavity at RIKEN

642

L. Lu
RIKEN, Saitama, Japan
O. Kamigaito, N. Sakamoto, K. Suda, K. Yamada
RIKEN Nishina Center, Wako, Japan

A design for a tri-spoke-type superconducting cavity for uranium beams with β = 0.303 and a 219 MHz operational frequency is presented. And a test model designed and assembled by two end-wall flanges and one triparted part of the designed tri-spoke cavity, was expected to be built using the same fabrication technology that is supposed for Nb cavity manufacture. The designs and simulations of the tri-spoke cavity and the test model will be reported in this paper.

TUPB095

Design of Coupler for Direct Coupled Amplifier to Drift Tube Linac Cavities of the Injector RILAC2 for RIKEN RI Beam Factory

684

K. Suda, S. Arai, Y. Chiba, O. Kamigaito, M. Kase, H. Okuno, N. Sakamoto, Y. Watanabe, K. Yamada
RIKEN Nishina Center, Wako, Japan

A new linac RILAC2 was constructed at RIKEN RI Beam Factory as an injector for very heavy ions such as uranium and xenon of a high mass to charge ratio m/q ∼ 7, but high intensity ions can be extracted from an ion source. Three drift tube linac cavities, operate in continuous wave mode at 36.5 MHz, have been designed and built. In order to reduce an installation area, and to save a construction cost, we adopted a direct coupling method for a power amplifier without using a long transmission line. A complicated design procedure was performed in order to take into account a change of resonant frequency of the cavity caused by a capacitance of a power tube used in the amplifier. A design of the coupler, as well as the cavity was performed using a three-dimensional electromagnetic calculation code, CST Microwave Studio (MWS). The measured input impedance seen from the amplifier (700 – 1100 Ω) was reproduced well by the calculation of MWS. Also, in order to examine MWS, a case of a coupling with 50 Ω were calculated. The coupling conditions obtained by MWS were compared with the measurement and a calculation with a lumped circuit model.

Paper	Title	Page
MO3A02	Commissioning of a New Injector for the RIKEN RI-Beam Factory	125
	N. Sakamoto, M. Fujimaki, H. Hasebe, Y. Higurashi, O. Kamigaito, H. Okuno, K. Suda, T. Watanabe, K. Yamada RIKEN Nishina Center, Wako, Japan R. Koyama SHI Accelerator Service Ltd., Tokyo, Japan
	A new injector for the RIKEN RI-Beam Factory (RIBF) has been fully commissioned since October 2011. The injector accelerates ions of m/q=6.8 up to 670 keV/u. In order to save the cost and space, a direct coupling scheme was adopted for rf coupling between the cavity and amplifier, based on an elaborate design with the Microwave Studio code. It has worked out very stably in these three months, making the uranium beam intensity higher by one order of magnitude. Moreover, it is now possible to operate the RIBF and GARIS facility for the super-heavy element synthesis independently.
	Slides MO3A02 [19.503 MB]

TUPB073	Design and Simulation of a Test Model for a Tri-Spoke Cavity at RIKEN	642
	L. Lu RIKEN, Saitama, Japan O. Kamigaito, N. Sakamoto, K. Suda, K. Yamada RIKEN Nishina Center, Wako, Japan
	A design for a tri-spoke-type superconducting cavity for uranium beams with β = 0.303 and a 219 MHz operational frequency is presented. And a test model designed and assembled by two end-wall flanges and one triparted part of the designed tri-spoke cavity, was expected to be built using the same fabrication technology that is supposed for Nb cavity manufacture. The designs and simulations of the tri-spoke cavity and the test model will be reported in this paper.

TUPB095	Design of Coupler for Direct Coupled Amplifier to Drift Tube Linac Cavities of the Injector RILAC2 for RIKEN RI Beam Factory	684
	K. Suda, S. Arai, Y. Chiba, O. Kamigaito, M. Kase, H. Okuno, N. Sakamoto, Y. Watanabe, K. Yamada RIKEN Nishina Center, Wako, Japan
	A new linac RILAC2 was constructed at RIKEN RI Beam Factory as an injector for very heavy ions such as uranium and xenon of a high mass to charge ratio m/q ∼ 7, but high intensity ions can be extracted from an ion source. Three drift tube linac cavities, operate in continuous wave mode at 36.5 MHz, have been designed and built. In order to reduce an installation area, and to save a construction cost, we adopted a direct coupling method for a power amplifier without using a long transmission line. A complicated design procedure was performed in order to take into account a change of resonant frequency of the cavity caused by a capacitance of a power tube used in the amplifier. A design of the coupler, as well as the cavity was performed using a three-dimensional electromagnetic calculation code, CST Microwave Studio (MWS). The measured input impedance seen from the amplifier (700 – 1100 Ω) was reproduced well by the calculation of MWS. Also, in order to examine MWS, a case of a coupling with 50 Ω were calculated. The coupling conditions obtained by MWS were compared with the measurement and a calculation with a lumped circuit model.