FEL2011 - List of Authors (Sei, N.)

Paper	Title	Page
MOPC13	Terahertz-Wave Spectrophotometry – Experiments of Compton Backscattering of Continuous-spectrum Coherent Transition Radiation	125
	N. Sei AIST, Tsukuba, Ibaraki, Japan T. Takahashi Kyoto University, Research Reactor Institute, Osaka, Japan
	Funding: This study was financially supported by the Sumitomo foundation. We have studied a terahertz-wave spectrophotometry by using Compton backscattering of coherent radiations at the Kyoto University Research Reactor Institute. In the terahertz-wave spectrophotometry, the characteristics of the continuous-spectrum THz waves are converted into those of the other wavelengths which are easily measured by colliding the THz waves with a relativistic electron beam. Such the continuous-spectrum light beam by Compton backscattering is known in a field of astrophysics. We achieved to observe a continuous-spectrum visible beam resulting from Compton backscattering using coherent transition radiations from an L-band electron linear accelerator. The measured spectrum of the Compton backscattered photons was similar to that calculated from the spectrum of coherent transition radiation. In the presentation, the experimental results of terahertz-wave spectrophotometry will be explained in detail. N. Sei and T. Takahashi, Appl. Phys. Express 3 (2010) 052401.

TUPA20	Third Harmonic Lasing in the NIJI-IV Storage Ring Free-Electron Lasers	239
	N. Sei, H. Ogawa, K. Yamada AIST, Tsukuba, Ibaraki, Japan
	Funding: This study was financially supported by the Budget for Nuclear Research of the Ministry of Education, Culture, Sports, Science and Technology. Studies of the storage ring free electron lasers (SRFELs) and their application experiments have progressed with the compact storage ring NIJI-IV at the National Institute of Advanced Industrial Science and Technology. We achieved SRFEL oscillations on the third harmonic in the near-infrared region. The measured gain and power of the third-harmonic FEL were consistent with those obtained by the storage ring FEL theory. The measured linewidth of the third-harmonic FEL was less than that of the fundamental FEL, and its pulse width was wider than that of the fundamental FEL. Our studies would be useful for a study of x-ray FEL oscillations with a resonator. In this presentation, characteristics of the higher-harmonic FELs with the NIJI-IV will be discussed in detail. : N. Sei et al., J. Phys. Soc. Jpn. 79 (2010) 093501.

Paper

Title

Page

Terahertz-Wave Spectrophotometry – Experiments of Compton Backscattering of Continuous-spectrum Coherent Transition Radiation

125

N. Sei
AIST, Tsukuba, Ibaraki, Japan
T. Takahashi
Kyoto University, Research Reactor Institute, Osaka, Japan

Funding: This study was financially supported by the Sumitomo foundation.
We have studied a terahertz-wave spectrophotometry by using Compton backscattering of coherent radiations at the Kyoto University Research Reactor Institute. In the terahertz-wave spectrophotometry, the characteristics of the continuous-spectrum THz waves are converted into those of the other wavelengths which are easily measured by colliding the THz waves with a relativistic electron beam. Such the continuous-spectrum light beam by Compton backscattering is known in a field of astrophysics. We achieved to observe a continuous-spectrum visible beam resulting from Compton backscattering using coherent transition radiations from an L-band electron linear accelerator*. The measured spectrum of the Compton backscattered photons was similar to that calculated from the spectrum of coherent transition radiation. In the presentation, the experimental results of terahertz-wave spectrophotometry will be explained in detail.
* N. Sei and T. Takahashi, Appl. Phys. Express 3 (2010) 052401.

TUPA20

Third Harmonic Lasing in the NIJI-IV Storage Ring Free-Electron Lasers

239

N. Sei, H. Ogawa, K. Yamada
AIST, Tsukuba, Ibaraki, Japan

Funding: This study was financially supported by the Budget for Nuclear Research of the Ministry of Education, Culture, Sports, Science and Technology.
Studies of the storage ring free electron lasers (SRFELs) and their application experiments have progressed with the compact storage ring NIJI-IV at the National Institute of Advanced Industrial Science and Technology. We achieved SRFEL oscillations on the third harmonic in the near-infrared region*. The measured gain and power of the third-harmonic FEL were consistent with those obtained by the storage ring FEL theory. The measured linewidth of the third-harmonic FEL was less than that of the fundamental FEL, and its pulse width was wider than that of the fundamental FEL. Our studies would be useful for a study of x-ray FEL oscillations with a resonator. In this presentation, characteristics of the higher-harmonic FELs with the NIJI-IV will be discussed in detail.
*: N. Sei et al., J. Phys. Soc. Jpn. 79 (2010) 093501.