FEL2012 - List of Authors (Hangyo, M.)

Paper	Title	Page
MOPD28	Theoretical Study of Smith-Purcell Free-Electron Lasers	85
	D. Li, K. Imasaki ILT, Suita, Osaka, Japan M.R. Asakawa, Y. Tsunawaki Kansai University, Osaka, Japan M. Hangyo ILE Osaka, Suita, Japan S. Miyamoto LASTI, Hyogo, Japan Y. Wei, Z. Yang UESTC, Chengdu, Sichuan, People's Republic of China
	We report here a theory to calculate the growth rate and start current of a Smith-Purcell free-electron lase. The mechanism of the interaction between a sheet electron beam and the surface wave above a lamellar grating is well investigated. After deriving the growth rate from the dispersion equation, the start current is dexterously worked out by considering the energy flow above the grating. The predictions of our theory agree with the results from the particle-in-cell simulations.

THPD40	Femtosecond Electron Bunch Measurement using THz Cherenkov Radiation in Dielectric Materials	622
	J. Yang, K. Kan, T. Kondoh, K. Norizawa, A. Ogata, T. Toigawa, Y. Yoshida ISIR, Osaka, Japan M. Hangyo ILE Osaka, Suita, Japan H. Kobayashi KEK, Ibaraki, Japan R. Kuroda, H. Toyokawa AIST, Ibaraki, Japan
	A novel method of femtosecond electron bunch measurement has been proposed using THz Cherenkov radiation in dielectric materials. When the ultrashort electron beam moves to the dielectric materials, such as a hollow quartz tube covered by a metal, the electron induced coherent Cherenkov radiation is occurred as a frequency spectrum in THz range with discrete components (higher mode radiations). The intensities of the THz components and the width of the frequency spectrum are determined strictly by the bunch length. In the preliminary experiments, we succeeded to observe the THz Cherenkov radiation from a 200 fs electron bunch using mm-sized dielectric tubes. It was found that the radiation spectra are dependent on the bunch length. The higher mode radiations are appeared by decreasing the electron bunch length.

Paper

Title

Page

Theoretical Study of Smith-Purcell Free-Electron Lasers

85

D. Li, K. Imasaki
ILT, Suita, Osaka, Japan
M.R. Asakawa, Y. Tsunawaki
Kansai University, Osaka, Japan
M. Hangyo
ILE Osaka, Suita, Japan
S. Miyamoto
LASTI, Hyogo, Japan
Y. Wei, Z. Yang
UESTC, Chengdu, Sichuan, People's Republic of China

We report here a theory to calculate the growth rate and start current of a Smith-Purcell free-electron lase. The mechanism of the interaction between a sheet electron beam and the surface wave above a lamellar grating is well investigated. After deriving the growth rate from the dispersion equation, the start current is dexterously worked out by considering the energy flow above the grating. The predictions of our theory agree with the results from the particle-in-cell simulations.

THPD40

Femtosecond Electron Bunch Measurement using THz Cherenkov Radiation in Dielectric Materials

622

J. Yang, K. Kan, T. Kondoh, K. Norizawa, A. Ogata, T. Toigawa, Y. Yoshida
ISIR, Osaka, Japan
M. Hangyo
ILE Osaka, Suita, Japan
H. Kobayashi
KEK, Ibaraki, Japan
R. Kuroda, H. Toyokawa
AIST, Ibaraki, Japan

A novel method of femtosecond electron bunch measurement has been proposed using THz Cherenkov radiation in dielectric materials. When the ultrashort electron beam moves to the dielectric materials, such as a hollow quartz tube covered by a metal, the electron induced coherent Cherenkov radiation is occurred as a frequency spectrum in THz range with discrete components (higher mode radiations). The intensities of the THz components and the width of the frequency spectrum are determined strictly by the bunch length. In the preliminary experiments, we succeeded to observe the THz Cherenkov radiation from a 200 fs electron bunch using mm-sized dielectric tubes. It was found that the radiation spectra are dependent on the bunch length. The higher mode radiations are appeared by decreasing the electron bunch length.