NewSUBARu synchrotron radiation facility

Apart from the 1.5 GeV electron storage ring, we have a compact electron linear accelerator LEENA (Laser Emitted ElectroN Accelerator) in our facility. Using LEENA, we have studied the infrared free electron laser and the generation of a high brightness electron beam using a needle cathode. Now, in order to develop terahertz light sources based on a compact linear accelerator, we statred research on advanced accelerators and light sources. In addition to soft X-ray from 1.5 GeV electron storage ring, we pursue the application of terahertz radiation, generated by LEENA, to industry.

Layout of 15 MeV Electron Linear Accelerator LEENA

An electron beam generated by a RF gun is accelerated up to 15 MeV after shortened in the bunch length by an alpha magnet. An accelerated electron beam goes through an achromatic lattice and an straight section for insertion devices, and is finally disposed at a beam dump.

Photos of LEENA Accelerator (RF-gun, alpha magnet, acceleration tube, achromatic lattice)

As terahertz light sources based on a compact linear accelerator, we plan to study the following and are making experimental setup.

• Smith-Purcell super radiation
• coherent synchrotron radiation from a bending magnet with short-bunched beams
• free electron laser in a tera-hertz regime

• "Enhanced Quantum Efficiency of Photocathode under High Electric Field", T.Inoue, S.Miyamoto, S.Amano, M.Yatsuzuka and T.Mochizuki, Jpn. J. Appl. Phys. Vol. 41 (2002) pp. 7402–7406
• "Design of Laser-Excited Needle-RF-Gun", T.Inoue, S.Miyamoto, S.Amano, M.Yatsuzuka and T.Mochizuki,　Jpn. J. Appl. Phys. Vol. 42 (2003) pp. 311–317