Sokendai - Okazaki, Okazaki, Aichi
UVSOR, Okazaki
Nagoya University, Nagoya
Light source technologies based on laser seeding are under development at the UVSOR-II electron storage ring. In the past experiments, we have succeeded in generating coherent THz radiation with various spectral properties and coherent DUV radiation with various polarizations. We carried out these experiments by utilizing a part of the existing free electron laser system and an SR beam-line opened for users. Last year, we started a new five year project, which contains construction of new undulators and beam lines dedicated to the source developments and also upgrade of the laser system. We have designed the seeding laser system and the undulators based on numerical simulations. A spectrometer for VUV has been constructed. A seeding light source based on HHG is under development. In this presentation, we report the results from the design studies and the preliminary experiments.
Kyoto IAE, Kyoto
UVSOR, Okazaki
We proposed a table-top seeded THz FEL amplifier using a multi-bunch photocathode RF gun and injection-seeded terahertz parametric generator (IS-TPG) [1]. Although the first numerical study was carried out under simplified condition [2], a slippage effect, which has prominent effect to long wavelength FEL was not taken into account. In order to discuss feasibility and expected THz output power, start-to-end simulation of FEL was performed by simulation code Parmela [3] and 3D time-dependent FET simulation code GENESIS 1.3 [4]. The peak output power of about 10 kW at 185μm was expected from the design scheme.
[1] K. Kawase, et al., Applied Physic Letters 80(2002),p195
[2] T. Kii, et al., Proc. of FEL2008, in press.
[3] L.M. Young, et al., PARMELA, LA-UR-96-1835,(2001)
[4] S. Reiche, NIM A429(1999) p242.
UVSOR, Okazaki
Nagoya University, Nagoya
Sokendai - Okazaki, Okazaki, Aichi
At the UVSOR storage ring, free electron laser (FEL) have been studied for more than a decade. After the upgrade of accelerator components in 2003, FEL lasing around 199 nm [1] has been achieved. In these years, several application experiments of the FEL in deep UV region have been carried out. A feedback alignment system of the optical resonator has been developed to improve long term stability of the laser power for user experiments. To promote application experiments more extensively, now we have two upgrade plans. One is FEL lasing with top-up operation in order to maintain a high beam current and then a high out-coupled power. The other is upgrade of the optical klystron to have higher gain at deep UV region. These two upgrades will allow us to attract more users to our FEL.
[1] M. Hosaka, “Lasing below 200 nm at the UVSOR-II FEL,” UVSOR Activity Report 2007.
Kyoto IAE, Kyoto
KAERI, Daejon
UVSOR, Okazaki
A mid-infrared free electron laser facility has been constructed for developing energy materials in Institute of Advanced Energy, Kyoto University. The accelerator has been installed and FEL gain saturation at 13.2 μm has been achieved in May 2008. The FEL power of about 3 MW has been observed at the accelerator room. We have constructed the FEL transport system from the accelerator room to the user room. The beam characterization at user room and preparation of the application of MIR-FEL will be introduced in the conference.
Kyoto IAE, Kyoto
UVSOR, Okazaki
A new type of undulator which consists of high-temperature superconductor bulk magnets in the staggered array configuration inside a solenoid is being developed, aimed at short period, high undulator field and controllability by the solenoid current.[1] In order to develop a numerical model, the field calculations were performed and comparisons were made with prototype measurements at the liquid nitrogen temperature. The field in the bulk magnet was modeled by loop currents of which amounts were determined by the critical current density which follow Bean model.[2] In the unsaturated condition, which is decided by the critical current density and the dimension of the bulk magnets, the field distributions and the dependence on the solenoid field were reproduced well. We then estimated the unsaturated performance at the liquid helium temperature, where increment of the critical current density is known [3] and significant improvement of the undulator performance is expected accordingly. In the conference, the experimental results, the detail of modeling and numerical results will be shown and also the performance estimation will be discussed.
[1] T. Kii, et al. FEL 2006, THPPH035 (2006),
R. Kinjo, et al., FEL 2008, THAAU03 (2008)
[2] C.P. Bean, Phys. Rev. Lett. 8, 250 (1962)
[3] M. Morita, et al. NIPPON STEEL TECHNICAL REPORT No. 93 (2006)
