PAC2013 - List of Authors (Kuroda, R.)

Paper

Title

Page

Ultra-Short Electron Bunch Generation by a Photocathode RF Gun

719

M. Mizugaki, Y. Koshiba, K. Sakaue, M. Washio
Waseda University, Tokyo, Japan
R. Kuroda
AIST, Tsukuba, Ibaraki, Japan
T. Takatomi, J. Urakawa
KEK, Ibaraki, Japan

We have been studying on the accelerator physics at Waseda University with BNL type 1.6cell rf gun. Such photocathode rf gun can generate low emittance and short bunch electron beam. Generating ultra-short electron bunch (shorter than 1ps) in a compact accelerator system would be meaningful because some applications need to be miniaturized, THz imaging, for example. However a short laser pulse cannot generate the bunch length of less than 1ps due to the space charge effects. So as to generate ultra-short electron bunch in compact system, we have newly designed Energy Chirping Cell attached rf gun (ECC rf gun). ECC is attached subsequently to the 1.6 cell. The role of ECC is to chirp the electron energy so that the electron bunch is compressed by velocity difference as it drifts. Simulation results show ECC rf gun can accelerate100pC electron bunch with the bunch length shorter than 100fs. We have successfully measured the coherent THz light by synchrotron radiation and transition radiation. Therefore, we inferred that the bunch was compressed into shorter than 1ps. In this conference, we will report the results of the bunch length measurement, present progresses and future plans.
JSPS Grant-in-Aid for Young Science (B) 23740203 and Scientific Research (A) 10001619

Slides WEOBA2 [7.527 MB]

WEOBB1

Development of THz-TDS System on the Basis of the S-band Compact Electron Linac

R. Kuroda
AIST, Tsukuba, Ibaraki, Japan

The terahertz (THz) radiation is a useful tool for progressing on security field. Especially, THz time-domain spectroscopy (THz-TDS) has recently emerged as a powerful probe for the investigation of various dangerous materials such as explosives. A high power THz source has been developed on the basis of the S-band compact electron linac at AIST. The THz pulse is generated with coherent radiation using ultra-short electron bunch with bunch length of less than 0.5 ps (rms) and energy of around 40 MeV. The THz pulse is detected by Electro-Optical (EO) sampling method with a ZnTe crystal like the pump-probe technique. The THz temporal waveform can be measured using the probe laser. The spectrum and the phase information of the sample is calculated by the Fourier Transform of the obtained waveform. In this conference, we will talk about details of our system and results of THz-TDS experiments.

Slides WEOBB1 [2.450 MB]

Paper	Title	Page
WEOBA2	Ultra-Short Electron Bunch Generation by a Photocathode RF Gun	719
	M. Mizugaki, Y. Koshiba, K. Sakaue, M. Washio Waseda University, Tokyo, Japan R. Kuroda AIST, Tsukuba, Ibaraki, Japan T. Takatomi, J. Urakawa KEK, Ibaraki, Japan
	We have been studying on the accelerator physics at Waseda University with BNL type 1.6cell rf gun. Such photocathode rf gun can generate low emittance and short bunch electron beam. Generating ultra-short electron bunch (shorter than 1ps) in a compact accelerator system would be meaningful because some applications need to be miniaturized, THz imaging, for example. However a short laser pulse cannot generate the bunch length of less than 1ps due to the space charge effects. So as to generate ultra-short electron bunch in compact system, we have newly designed Energy Chirping Cell attached rf gun (ECC rf gun). ECC is attached subsequently to the 1.6 cell. The role of ECC is to chirp the electron energy so that the electron bunch is compressed by velocity difference as it drifts. Simulation results show ECC rf gun can accelerate100pC electron bunch with the bunch length shorter than 100fs. We have successfully measured the coherent THz light by synchrotron radiation and transition radiation. Therefore, we inferred that the bunch was compressed into shorter than 1ps. In this conference, we will report the results of the bunch length measurement, present progresses and future plans. JSPS Grant-in-Aid for Young Science (B) 23740203 and Scientific Research (A) 10001619
	Slides WEOBA2 [7.527 MB]

WEOBB1	Development of THz-TDS System on the Basis of the S-band Compact Electron Linac
	R. Kuroda AIST, Tsukuba, Ibaraki, Japan
	The terahertz (THz) radiation is a useful tool for progressing on security field. Especially, THz time-domain spectroscopy (THz-TDS) has recently emerged as a powerful probe for the investigation of various dangerous materials such as explosives. A high power THz source has been developed on the basis of the S-band compact electron linac at AIST. The THz pulse is generated with coherent radiation using ultra-short electron bunch with bunch length of less than 0.5 ps (rms) and energy of around 40 MeV. The THz pulse is detected by Electro-Optical (EO) sampling method with a ZnTe crystal like the pump-probe technique. The THz temporal waveform can be measured using the probe laser. The spectrum and the phase information of the sample is calculated by the Fourier Transform of the obtained waveform. In this conference, we will talk about details of our system and results of THz-TDS experiments.
	Slides WEOBB1 [2.450 MB]