IPAC2013 - List of Authors (Furukawa, K.)

Paper	Title	Page
MOPFI018	Design Study of a New Large Aperture Flux Concentrator	318
	L. Zang, M. Akemoto, S. Fukuda, K. Furukawa, T. Higo, K. Kakihara, T. Kamitani, Y. Ogawa, H. Someya, T. Takatomi KEK, Ibaraki, Japan
	For high luminosity electron-positron colliders, intense positron beam production is one of the key issues. Flux Concentrator (FC) is a pulsed solenoid that can generate high magnetic field of several Tesla and is often used for focusing positrons emerged from a production target. It works as an optical matching device in a positron capture section. With this device, high capture efficiency is achieved. In this paper, we will introduce a new design of a FC for the SuperKEKB positron source. The advantages of the new design are: 1. the aperture could be doubled of the previous design, 2. the transverse components are only 1/10 of the previous design, 3. maintain the same high peak longitudinal field. The new FC modeling has been done in CST Studio and we will report the results of new FC field evaluation. In order to calculate the positron yield and capture efficiency, a tracking simulation to the end of capture section has also been carried out, which is also included in this paper.

TUPME010	High-intensity and Low-emittance Upgrade of 7-GeV Injector Linac towards SuperKEKB	1583
	K. Furukawa, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, H. Honma, R. Ichimiya, N. Iida, M. Ikeda, E. Kadokura, K. Kakihara, T. Kamitani, H. Katagiri, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, T. Mori, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, S. Ohsawa, F. Qiu, M. Satoh, T. Shidara, A. Shirakawa, H. Sugimoto, T. Suwada, T. Takatomi, T. Takenaka, M. Tanaka, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou KEK, Ibaraki, Japan D. Satoh TIT, Tokyo, Japan
	After a decade of successful operation at KEKB a new electron/positron collider, SuperKEKB, is being constructed to commission within FY2014. It aims at a luminosity of 8 x 10³⁵ /s.cm², 40-times higher than that of KEKB, in order to study the flavor physics of elementary particles further, by mainly squeezing the beams at the collision point. The injector linac should provide high-intensity and low-emittance beams of 7-GeV electron and 4-GeV positron by newly installing a RF-gun, a flux concentrator, and a damping ring with careful emittance and energy management. It also have to perform simultaneous top-up injections into four storage rings by pulse-to-pulse beam modulations not to interfare between three facilities of SuperKEKB, Photon Factory and PF-AR. This paper describes the injector design decisions and present status of the construction.

WEPME017	Development and Application of the Trigger Timing Watchdog System in KEK Electron/Positron Linac	2962
	M. Satoh, K. Furukawa, F. Miyahara, T. Suwada KEK, Ibaraki, Japan T. Kudou, S. Kusano Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
	The KEK injector linac provides electrons and positrons to several accelerator facilities. A 50 Hz beam-mode switching system has been constructed to realize simultaneous top-up injections for Photon Factory and the KEKB high- and low-energy rings, which require different beam characteristics. An event-based timing and control system was built to change the parameters of various accelerator components within 20 ms. The components are spread over a 600-m-long linac and require changes to a total of 100 timing and control parameters. The system has been operated successfully since the autumn of 2008 and has been improved upon as beam operation experience has been accumulated. The timing watchdog and alert system are indispensable for the stable and high quality beam operation. For this purpose, we developed and utilized several timing watchdog system. We will present the detail of timing signal watchdog system for the KEK injector linac.

Paper

Title

Page

Design Study of a New Large Aperture Flux Concentrator

318

L. Zang, M. Akemoto, S. Fukuda, K. Furukawa, T. Higo, K. Kakihara, T. Kamitani, Y. Ogawa, H. Someya, T. Takatomi
KEK, Ibaraki, Japan

For high luminosity electron-positron colliders, intense positron beam production is one of the key issues. Flux Concentrator (FC) is a pulsed solenoid that can generate high magnetic field of several Tesla and is often used for focusing positrons emerged from a production target. It works as an optical matching device in a positron capture section. With this device, high capture efficiency is achieved. In this paper, we will introduce a new design of a FC for the SuperKEKB positron source. The advantages of the new design are: 1. the aperture could be doubled of the previous design, 2. the transverse components are only 1/10 of the previous design, 3. maintain the same high peak longitudinal field. The new FC modeling has been done in CST Studio and we will report the results of new FC field evaluation. In order to calculate the positron yield and capture efficiency, a tracking simulation to the end of capture section has also been carried out, which is also included in this paper.

TUPME010

High-intensity and Low-emittance Upgrade of 7-GeV Injector Linac towards SuperKEKB

1583

K. Furukawa, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, H. Honma, R. Ichimiya, N. Iida, M. Ikeda, E. Kadokura, K. Kakihara, T. Kamitani, H. Katagiri, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, T. Mori, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, S. Ohsawa, F. Qiu, M. Satoh, T. Shidara, A. Shirakawa, H. Sugimoto, T. Suwada, T. Takatomi, T. Takenaka, M. Tanaka, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou
KEK, Ibaraki, Japan
D. Satoh
TIT, Tokyo, Japan

After a decade of successful operation at KEKB a new electron/positron collider, SuperKEKB, is being constructed to commission within FY2014. It aims at a luminosity of 8 x 10³⁵ /s.cm², 40-times higher than that of KEKB, in order to study the flavor physics of elementary particles further, by mainly squeezing the beams at the collision point. The injector linac should provide high-intensity and low-emittance beams of 7-GeV electron and 4-GeV positron by newly installing a RF-gun, a flux concentrator, and a damping ring with careful emittance and energy management. It also have to perform simultaneous top-up injections into four storage rings by pulse-to-pulse beam modulations not to interfare between three facilities of SuperKEKB, Photon Factory and PF-AR. This paper describes the injector design decisions and present status of the construction.

WEPME017

Development and Application of the Trigger Timing Watchdog System in KEK Electron/Positron Linac

2962

M. Satoh, K. Furukawa, F. Miyahara, T. Suwada
KEK, Ibaraki, Japan
T. Kudou, S. Kusano
Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan

The KEK injector linac provides electrons and positrons to several accelerator facilities. A 50 Hz beam-mode switching system has been constructed to realize simultaneous top-up injections for Photon Factory and the KEKB high- and low-energy rings, which require different beam characteristics. An event-based timing and control system was built to change the parameters of various accelerator components within 20 ms. The components are spread over a 600-m-long linac and require changes to a total of 100 timing and control parameters. The system has been operated successfully since the autumn of 2008 and has been improved upon as beam operation experience has been accumulated. The timing watchdog and alert system are indispensable for the stable and high quality beam operation. For this purpose, we developed and utilized several timing watchdog system. We will present the detail of timing signal watchdog system for the KEK injector linac.