IPAC2011 - List of Authors (Shimizu, H.)

Paper	Title	Page
TUPO012	Stable Planner Type Four-mirror Cavity Development for X-ray Production as Basic Development of Quantum Beam Technology Program	1470
	H. Shimizu, Y. Higashi, Y. Honda, J. Urakawa KEK, Ibaraki, Japan
	As the development of quantum beam technology program, a facility to produce a semi-monochromatic X-ray via inverse Compton scattering with an electron beam accelerated by a superconducting RF cavity and a fiber amplified high power laser stacked in an external optical cavity system are now under construction. To achieve high brightness of Compton X-ray, we introduced a chicane with about a 1m-long zero dispersion straight section that includes IP. Head on collision scheme improves the yield of X-ray, but to do so, a huge and stout external optical cavity system must be needed. According to this demand, we develop a quite tolerable planner type four-mirror cavity with movable mirror mount system. In this paper, results obtained by the cavity construction and also laser development activities are described.

TUPO002	High Flux Polarized Gamma Rays Production: First Measurements with a Four-mirror Cavity at the ATF	1446
	N. Delerue, J. Bonis, I. Chaikovska, R. Chiche, R. Cizeron, M. Cohen, P. Cornebise, R. Flaminio, D. Jehanno, F. Labaye, M. Lacroix, Y. Peinaud, L. Pinard, V. Soskov, A. Variola, Z.F. Zomer LAL, Orsay, France T. Akagi, S. Miyoshi Hiroshima University, Graduate School of Advanced Sciences of Matter, Higashi-Hiroshima, Japan S. Araki, Y. Funahashi, Y. Honda, T. Omori, H. Shimizu, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan E. Cormier CELIA, Talence, France T. Takahashi Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
	Funding: ANR, IN2P3 The next generation of e+/e^- colliders will require the production of a very intense flux of gamma rays to allow polarized positrons to be produced in sufficient quantities. To demonstrate that this can be achieved a four-mirror cavity has recently been installed at the Accelerator Test Facility (ATF) at KEK to produce a high flux of polarized gamma rays by inverse Compton scattering. A four-mirror non-planar geometry is used to ensure the polarization of the gamma rays produced. The main mechanical features of the cavity are presented. A fibre amplifier is used to inject about 10W in the high finesse cavity with a gain of 1000. A digital feedback system is used to keep the cavity at the length required for the optimal power enhancement. First preliminary measurements show that on some beam crossings the interactions produce more than 25 photons with an average energy of about 24 MeV. Several upgrades currently in progress are described.

Paper

Title

Page

Stable Planner Type Four-mirror Cavity Development for X-ray Production as Basic Development of Quantum Beam Technology Program

1470

H. Shimizu, Y. Higashi, Y. Honda, J. Urakawa
KEK, Ibaraki, Japan

As the development of quantum beam technology program, a facility to produce a semi-monochromatic X-ray via inverse Compton scattering with an electron beam accelerated by a superconducting RF cavity and a fiber amplified high power laser stacked in an external optical cavity system are now under construction. To achieve high brightness of Compton X-ray, we introduced a chicane with about a 1m-long zero dispersion straight section that includes IP. Head on collision scheme improves the yield of X-ray, but to do so, a huge and stout external optical cavity system must be needed. According to this demand, we develop a quite tolerable planner type four-mirror cavity with movable mirror mount system. In this paper, results obtained by the cavity construction and also laser development activities are described.

TUPO002

High Flux Polarized Gamma Rays Production: First Measurements with a Four-mirror Cavity at the ATF

1446

N. Delerue, J. Bonis, I. Chaikovska, R. Chiche, R. Cizeron, M. Cohen, P. Cornebise, R. Flaminio, D. Jehanno, F. Labaye, M. Lacroix, Y. Peinaud, L. Pinard, V. Soskov, A. Variola, Z.F. Zomer
LAL, Orsay, France
T. Akagi, S. Miyoshi
Hiroshima University, Graduate School of Advanced Sciences of Matter, Higashi-Hiroshima, Japan
S. Araki, Y. Funahashi, Y. Honda, T. Omori, H. Shimizu, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
E. Cormier
CELIA, Talence, France
T. Takahashi
Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan

Funding: ANR, IN2P3
The next generation of e+/e^- colliders will require the production of a very intense flux of gamma rays to allow polarized positrons to be produced in sufficient quantities. To demonstrate that this can be achieved a four-mirror cavity has recently been installed at the Accelerator Test Facility (ATF) at KEK to produce a high flux of polarized gamma rays by inverse Compton scattering. A four-mirror non-planar geometry is used to ensure the polarization of the gamma rays produced. The main mechanical features of the cavity are presented. A fibre amplifier is used to inject about 10W in the high finesse cavity with a gain of 1000. A digital feedback system is used to keep the cavity at the length required for the optimal power enhancement. First preliminary measurements show that on some beam crossings the interactions produce more than 25 photons with an average energy of about 24 MeV. Several upgrades currently in progress are described.