IPAC2013 - List of Authors (Mitsuda, C.)

Paper	Title	Page
MOPEA027	New Optics with Emittance Reduction at the SPring-8 Storage Ring	133
	Y. Shimosaki, K. Fukami, K.K. Kaneki, K. Kobayashi, M. Masaki, C. Mitsuda, T. Nakamura, T. Nakanishi, H. Ohkuma, M. Oishi, M. Shoji, K. Soutome, S. Takano, M. Takao JASRI/SPring-8, Hyogo-ken, Japan
	The machine tuning of a new optics is in progress at the SPring-8 storage ring, in order not only to provide brilliant photons for current users but also to study a strategy of a lattice design and a tuning scenario for the upgrade project SPring-8 II. The natural emittance is reduced to 2.4 nmrad from the present value of 3.4 nmrad without any change of magnet positions. The flux density 1.3 times higher than the present was observed at the diagnostics beamline. The nominal injection efficiency of the order of 80 % has been achieved (the present: 92 %) by correcting the error of the optics function, by adjusting the strength of the injection magnets and by optimizing the sextupole magnetic fields. The beam lifetime was 13 h at 1 mA / bunch (the present: 22 h), and the momentum aperture estimated from the measurement of the Touschek lifetime was 2.3 % (the present: 2.8 %). Though these are tolerable to the user operation, further optimization of the sextupoles is ongoing. After verifying the photon beam performance at beamlines, this new optics will be applied to the user operation. The optics design and its beam performance will be presented in detail.

MOPWA003	New Development of Compact Fast Pulsed Power Supply System in the SPring-8	666
	C. Mitsuda, K. Fukami, K. Kobayashi, T. Nakanishi, H. Ohkuma, S. Sasaki JASRI/SPring-8, Hyogo-ken, Japan T. Ohshima RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	We have developed a compact fast pulsed power supply system as a part of the development of the fast kicker magnet system in the SPring-8 storage ring. The kicker magnet is needed for the 1 ps short pulsed X-ray generation by a vertical kick and the suppression of the fast beam oscillation by counter kick. The required pulse width and current for above applications have to be a enough short time less than 4.8 us of the revolution time and more than 200 A respectively. We selected a Si-MOSFET as a switching device because a MOSFET has two capabilities of the fast switching and high-voltage resistance, and has a smaller size than an IGBT. The current are increased by parallel or parallel-series connecting of MOSFETs. We started the development of a test system whose output current was a 67 A with a pulse width of 1.0 us in 2008. From 2009 to 2011, we succeeded in achieving the output current of a 270 A with a pulse width of 0.8 us by using prototype system. In 2012, by increasing the number of MOSFET, we confirmed the output current of 250 A with a pulse width of 0.5 us, whose case size is a just 210(W) x 160(H) x 300(D) mm. We will report the development status in detail.

Paper

Title

Page

New Optics with Emittance Reduction at the SPring-8 Storage Ring

133

Y. Shimosaki, K. Fukami, K.K. Kaneki, K. Kobayashi, M. Masaki, C. Mitsuda, T. Nakamura, T. Nakanishi, H. Ohkuma, M. Oishi, M. Shoji, K. Soutome, S. Takano, M. Takao
JASRI/SPring-8, Hyogo-ken, Japan

The machine tuning of a new optics is in progress at the SPring-8 storage ring, in order not only to provide brilliant photons for current users but also to study a strategy of a lattice design and a tuning scenario for the upgrade project SPring-8 II. The natural emittance is reduced to 2.4 nmrad from the present value of 3.4 nmrad without any change of magnet positions. The flux density 1.3 times higher than the present was observed at the diagnostics beamline. The nominal injection efficiency of the order of 80 % has been achieved (the present: 92 %) by correcting the error of the optics function, by adjusting the strength of the injection magnets and by optimizing the sextupole magnetic fields. The beam lifetime was 13 h at 1 mA / bunch (the present: 22 h), and the momentum aperture estimated from the measurement of the Touschek lifetime was 2.3 % (the present: 2.8 %). Though these are tolerable to the user operation, further optimization of the sextupoles is ongoing. After verifying the photon beam performance at beamlines, this new optics will be applied to the user operation. The optics design and its beam performance will be presented in detail.

MOPWA003

New Development of Compact Fast Pulsed Power Supply System in the SPring-8

666

C. Mitsuda, K. Fukami, K. Kobayashi, T. Nakanishi, H. Ohkuma, S. Sasaki
JASRI/SPring-8, Hyogo-ken, Japan
T. Ohshima
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

We have developed a compact fast pulsed power supply system as a part of the development of the fast kicker magnet system in the SPring-8 storage ring. The kicker magnet is needed for the 1 ps short pulsed X-ray generation by a vertical kick and the suppression of the fast beam oscillation by counter kick. The required pulse width and current for above applications have to be a enough short time less than 4.8 us of the revolution time and more than 200 A respectively. We selected a Si-MOSFET as a switching device because a MOSFET has two capabilities of the fast switching and high-voltage resistance, and has a smaller size than an IGBT. The current are increased by parallel or parallel-series connecting of MOSFETs. We started the development of a test system whose output current was a 67 A with a pulse width of 1.0 us in 2008. From 2009 to 2011, we succeeded in achieving the output current of a 270 A with a pulse width of 0.8 us by using prototype system. In 2012, by increasing the number of MOSFET, we confirmed the output current of 250 A with a pulse width of 0.5 us, whose case size is a just 210(W) x 160(H) x 300(D) mm. We will report the development status in detail.