IPAC2015 - List of Authors (Kondoh, T.)

Paper	Title	Page
MOPTY002	Bunch Length Measurement of Femtosecond Electron Beam by Monitoring Coherent Transition Radiation	940
	I. Nozawa, M. Gohdo, K. Kan, T. Kondoh, A. Ogata, J. Yang, Y. Yoshida ISIR, Osaka, Japan
	Ultrashort electron bunches with durations of femtoseconds and attoseconds are essential for time-resolved measurements, including pulse radiolysis and ultrafast electron microscopy. However, generation of the ultrashort electron bunches is commonly difficult because of bunch length growth due to space charge effect, nonlinear momentum dispersion and so on. Several bunch length measurement methods for the ultrashort electron beams have also been considered so far, which have not been established yet. In this study, the femtosecond electron beams were generated using a laser photocathode radio-frequency gun linac and a magnetic bunch compressor. The bunch length measurement was carried out using a Michelson interferometer based on monitoring coherent transition radiation (CTR), which is characterized by square modulus of the Fourier transform of the longitudinal bunch distribution. Analyzing the experimentally obtained interferograms of CTR, the electron beams with the average duration of 5 fs were generated and measured successfully at the condition of bunch charge of 1 pC. Consideration of the longitudinal bunch shapes was also carried out using the Kramers-Kronig relation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPTY002
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TUPJE007	Measurement of Temporal Electric Field of Electron Bunch using Photoconductive Antenna	1623
	K. Kan, M. Gohdo, T. Kondoh, I. Nozawa, A. Ogata, T. Toigawa, J. Yang, Y. Yoshida ISIR, Osaka, Japan
	A temporal electric field profile, which is a radially polarized terahertz (THz) pulse from an electron bunch, was measured by a large-aperture photoconductive antenna (PCA) with micro-structured concentric electrodes* for the detection of THz pulses. Photo-induced charge carriers were generated by irradiation of femtosecond laser pulses on semiconductor plane of the electrodes on the PCA. Time-domain measurement of coherent transition radiation (CTR) was conducted by the measurement of electric-field-induced current output from the PCA with sweeping the timing of the laser irradiation. The measurements on femtosecond electron bunches of 32 MeV and >80 pC will be reported. * K. Kan et al., Appl. Phys. Lett. 102, 221118 (2013).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE007
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Paper

Title

Page

Bunch Length Measurement of Femtosecond Electron Beam by Monitoring Coherent Transition Radiation

940

I. Nozawa, M. Gohdo, K. Kan, T. Kondoh, A. Ogata, J. Yang, Y. Yoshida
ISIR, Osaka, Japan

Ultrashort electron bunches with durations of femtoseconds and attoseconds are essential for time-resolved measurements, including pulse radiolysis and ultrafast electron microscopy. However, generation of the ultrashort electron bunches is commonly difficult because of bunch length growth due to space charge effect, nonlinear momentum dispersion and so on. Several bunch length measurement methods for the ultrashort electron beams have also been considered so far, which have not been established yet. In this study, the femtosecond electron beams were generated using a laser photocathode radio-frequency gun linac and a magnetic bunch compressor. The bunch length measurement was carried out using a Michelson interferometer based on monitoring coherent transition radiation (CTR), which is characterized by square modulus of the Fourier transform of the longitudinal bunch distribution. Analyzing the experimentally obtained interferograms of CTR, the electron beams with the average duration of 5 fs were generated and measured successfully at the condition of bunch charge of 1 pC. Consideration of the longitudinal bunch shapes was also carried out using the Kramers-Kronig relation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPTY002

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPJE007

Measurement of Temporal Electric Field of Electron Bunch using Photoconductive Antenna

1623

K. Kan, M. Gohdo, T. Kondoh, I. Nozawa, A. Ogata, T. Toigawa, J. Yang, Y. Yoshida
ISIR, Osaka, Japan

A temporal electric field profile, which is a radially polarized terahertz (THz) pulse from an electron bunch, was measured by a large-aperture photoconductive antenna (PCA) with micro-structured concentric electrodes* for the detection of THz pulses. Photo-induced charge carriers were generated by irradiation of femtosecond laser pulses on semiconductor plane of the electrodes on the PCA. Time-domain measurement of coherent transition radiation (CTR) was conducted by the measurement of electric-field-induced current output from the PCA with sweeping the timing of the laser irradiation. The measurements on femtosecond electron bunches of 32 MeV and >80 pC will be reported.
* K. Kan et al., Appl. Phys. Lett. 102, 221118 (2013).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE007

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)