Development of RF gun producing high intensity and polarized electron beam

2015 Fiscal Year Final Research Report

• Project/Area Number: 24654054
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Tohoku University
• Principal Investigator: Kashiwagi Shigeru 東北大学, 電子光理学研究センター, 准教授 (60329133)
• Co-Investigator(Kenkyū-buntansha): HINODE Fujio 東北大学, 電子光理学研究センター, 准教授 (60292207) ; KURIKI Masao 広島大学, 先端物質科学研究科, 教授 (80321537)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: 電子ビーム / 低エミッタンス / 偏極ビーム / エミッタンス交換

Outline of Final Research Achievements

We have developed a photocathode RF gun with DAW structure type to generate an extremely low emittance and spin polarized electron beam. NEA-GaAs cathode is used for generation of spin polarized electron beam, NEA-GaAs has a vulnerability issue and it requires an ultra-high vacuum level. It has confirmed that it is possible to install the additional vacuum pumping system to the DAW type of RF gun system without reducing the Q-value of cavities. On the other hand, to overcome a vulnerability issue of NEA surface, we evaporated CsTe semi-conductor thin film on GaAs surface and obtained a result which suggest NEA surface on GaAs wafer. This could be another technique for the NEA activation with Cs-O/F. To make the high aspect ratio of the beam shape, the X-Y emittance exchange technique is employed for RF gun system. We have performed tracking simulation for KEK-STF beam line. We established the emittance exchange method by using solenoid magnet and a set of skew quadrupole magnets.

Free Research Field

加速器科学