IPAC2021 - List of Authors (Honda, Y.)

Paper	Title	Page
MOPAB330	Production and Performance Evaluation of a Compact Deflecting Cavity to Measure the Bunch Length in the cERL	1023
	D. Naito, Y. Honda, T. Miyajima, N. Yamamoto KEK, Ibaraki, Japan
	At the KEK compact energy recovery linac, we try to generate an infrared free-electron laser (FEL). To generate the FEL, an electron bunch should be compressed along the longitudinal direction. The measurement of the bunch length is key to optimize the bunch compression. We plan to measure the bunch length by deflecting cavities in the burst mode. The deflecting cavities are required to be a time resolution of 33 fs in order to not only measure the bunch length but also resolve the structure inside the electron bunch. To achieve the requirement, we developed a c-band cavity whose RF input port is compact. The deflecting cavity is a single cell and normal conducting cavity. The deflection mode of the cavity is TM110. The 12 cavities will be located at the exit of undulators. In this presentation, we explain the design of our cavity and report the production of the first cavity. We also report the evaluation of the resonance frequency, the unloaded Q and the external Q of the cavity. From the measurements and simulations, the R/Q is estimated to be 1 mega orms. The time resolution of the cavity is expected to be 400 fs when the input RF power is 1 kW and the beam energy is 20 MeV.
	Poster MOPAB330 [12.920 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB330
About •	paper received ※ 12 May 2021 paper accepted ※ 08 June 2021 issue date ※ 28 August 2021
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TUPAB064	Specifications and Performance of a Chicane Magnet for the cERL IR-FEL	1512
	N. Nakamura, K. Harada, N. Higashi, Y. Honda, R. Kato, C. Mitsuda, S. Nagahashi, T. Obina, H. Sakai, M. Shimada, H. Takaki, O.A. Tanaka KEK, Ibaraki, Japan Y. Lu Sokendai, Ibaraki, Japan
	Funding: Work supported by NEDO project "Development of advanced laser processing with intelligence based high-brightness and high-efficiency laser technologies (TACMI project)". The IR-FEL was constructed in the Compact ERL (cERL) at KEK from October 2019 to May 2020 for the purpose of developing high-power mid-infrared lasers for high-efficiency laser processing utilizing molecular vibrational absorption. The chicane magnet was newly installed between two IR-FEL undulators in the cERL in order to increase the FEL gain and pulse energy by converting the energy modulation to the density modulation in an electron bunch. It consists of three dipole magnets with laminated yokes made of 0.1-mm-thick permalloy sheets and the coil currents of the three magnets are independently controlled by three power supplies with the maximum current of 10 A. The maximum closed orbit bump made by the chicane magnetic field has the longitudinal dispersion(R56) of -6 mm. The coil-current ratio of the three dipole magnets was tuned after installation to make its orbit bumps closed and then the chicane magnet was used in the FEL operation. We present specifications and operational performance of the chicane magnet.
	Poster TUPAB064 [4.053 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB064
About •	paper received ※ 18 May 2021 paper accepted ※ 25 May 2021 issue date ※ 25 August 2021
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TUPAB099	Construction of an Infrared FEL at the Compact ERL	1608
	R. Kato, M. Adachi, S. Eguchi, K. Harada, N. Higashi, Y. Honda, T. Miyajima, S. Nagahashi, N. Nakamura, K.N. Nigorikawa, T. Nogami, T. Obina, H. Sagehashi, H. Sakai, M. Shimada, T. Shioya, M. Tadano, R. Takai, O.A. Tanaka, Y. Tanimoto, K. Tsuchiya, T. Uchiyama, A. Ueda, M. Yamamoto KEK, Ibaraki, Japan R. Hajima QST, Tokai, Japan N.P. Norvell SLAC, Menlo Park, California, USA F. Sakamoto Akita National College of Technology, Akita, Japan M. Shimada HSRC, Higashi-Hiroshima, Japan
	Funding: Work supported by NEDO project "Development of advanced laser processing with intelligence based high-brightness and high-efficiency laser technologies (TACMI project)". The compact Energy Recovery Linac (cERL) has been in operation at KEK since 2013 to demonstrate ERL performance and develop ERL technology. Recently KEK has launched an infrared FEL project with a competitive funding. The purpose of this project is to build a mid-infrared FEL at the cERL, and to use that FEL as a light source for construction of the processing database required for industrial lasers. The FEL system is composed of two 3-m undulators and a matching section between them, and generates light with a maximum pulse energy of 0.1 micro-J at the wavelength of 20 microns with an 81.25 MHz repetition rate. The FEL is also expected to become a proof-of-concept machine for ERL base FELs for future EUV lithography.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB099
About •	paper received ※ 20 May 2021 paper accepted ※ 14 June 2021 issue date ※ 29 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Production and Performance Evaluation of a Compact Deflecting Cavity to Measure the Bunch Length in the cERL

1023

D. Naito, Y. Honda, T. Miyajima, N. Yamamoto
KEK, Ibaraki, Japan

At the KEK compact energy recovery linac, we try to generate an infrared free-electron laser (FEL). To generate the FEL, an electron bunch should be compressed along the longitudinal direction. The measurement of the bunch length is key to optimize the bunch compression. We plan to measure the bunch length by deflecting cavities in the burst mode. The deflecting cavities are required to be a time resolution of 33 fs in order to not only measure the bunch length but also resolve the structure inside the electron bunch. To achieve the requirement, we developed a c-band cavity whose RF input port is compact. The deflecting cavity is a single cell and normal conducting cavity. The deflection mode of the cavity is TM110. The 12 cavities will be located at the exit of undulators. In this presentation, we explain the design of our cavity and report the production of the first cavity. We also report the evaluation of the resonance frequency, the unloaded Q and the external Q of the cavity. From the measurements and simulations, the R/Q is estimated to be 1 mega orms. The time resolution of the cavity is expected to be 400 fs when the input RF power is 1 kW and the beam energy is 20 MeV.

Poster MOPAB330 [12.920 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB330

About •

paper received ※ 12 May 2021 paper accepted ※ 08 June 2021 issue date ※ 28 August 2021

Export •

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

TUPAB064

Specifications and Performance of a Chicane Magnet for the cERL IR-FEL

1512

N. Nakamura, K. Harada, N. Higashi, Y. Honda, R. Kato, C. Mitsuda, S. Nagahashi, T. Obina, H. Sakai, M. Shimada, H. Takaki, O.A. Tanaka
KEK, Ibaraki, Japan
Y. Lu
Sokendai, Ibaraki, Japan

Funding: Work supported by NEDO project "Development of advanced laser processing with intelligence based high-brightness and high-efficiency laser technologies (TACMI project)".
The IR-FEL was constructed in the Compact ERL (cERL) at KEK from October 2019 to May 2020 for the purpose of developing high-power mid-infrared lasers for high-efficiency laser processing utilizing molecular vibrational absorption. The chicane magnet was newly installed between two IR-FEL undulators in the cERL in order to increase the FEL gain and pulse energy by converting the energy modulation to the density modulation in an electron bunch. It consists of three dipole magnets with laminated yokes made of 0.1-mm-thick permalloy sheets and the coil currents of the three magnets are independently controlled by three power supplies with the maximum current of 10 A. The maximum closed orbit bump made by the chicane magnetic field has the longitudinal dispersion(R56) of -6 mm. The coil-current ratio of the three dipole magnets was tuned after installation to make its orbit bumps closed and then the chicane magnet was used in the FEL operation. We present specifications and operational performance of the chicane magnet.

Poster TUPAB064 [4.053 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB064

About •

paper received ※ 18 May 2021 paper accepted ※ 25 May 2021 issue date ※ 25 August 2021

Export •

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

TUPAB099

Construction of an Infrared FEL at the Compact ERL

1608

R. Kato, M. Adachi, S. Eguchi, K. Harada, N. Higashi, Y. Honda, T. Miyajima, S. Nagahashi, N. Nakamura, K.N. Nigorikawa, T. Nogami, T. Obina, H. Sagehashi, H. Sakai, M. Shimada, T. Shioya, M. Tadano, R. Takai, O.A. Tanaka, Y. Tanimoto, K. Tsuchiya, T. Uchiyama, A. Ueda, M. Yamamoto
KEK, Ibaraki, Japan
R. Hajima
QST, Tokai, Japan
N.P. Norvell
SLAC, Menlo Park, California, USA
F. Sakamoto
Akita National College of Technology, Akita, Japan
M. Shimada
HSRC, Higashi-Hiroshima, Japan

Funding: Work supported by NEDO project "Development of advanced laser processing with intelligence based high-brightness and high-efficiency laser technologies (TACMI project)".
The compact Energy Recovery Linac (cERL) has been in operation at KEK since 2013 to demonstrate ERL performance and develop ERL technology. Recently KEK has launched an infrared FEL project with a competitive funding. The purpose of this project is to build a mid-infrared FEL at the cERL, and to use that FEL as a light source for construction of the processing database required for industrial lasers. The FEL system is composed of two 3-m undulators and a matching section between them, and generates light with a maximum pulse energy of 0.1 micro-J at the wavelength of 20 microns with an 81.25 MHz repetition rate. The FEL is also expected to become a proof-of-concept machine for ERL base FELs for future EUV lithography.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB099

About •

paper received ※ 20 May 2021 paper accepted ※ 14 June 2021 issue date ※ 29 August 2021

Export •

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