LINAC2022 - Classification: Electron Accelerators and Applications / Synchrotron light sources

Paper	Title	Page
MOPOJO18	Manipulation and Measurement of Polarization State for THz Coherent Undulator Radiation	69
	S. Kashiwagi, H. Hama, F. Hinode, T. Muto, I. Nagasawa, K. Nanbu, H. Saito Tohoku University, Research Center for Electron Photon Science, Sendai, Japan A. Irizawa ISIR, Osaka, Japan H. Zen Kyoto University, Kyoto, Japan
	We are developing an accelerator-based terahertz source that can produce arbitrary polarization states from linearly polarized coherent undulator radiation (CUR). The polarization manipulation of the CUR can be realized using the Martin’Puplett interferometer employed as an optical phase shifter. This study also demonstrates a variable polarization manipulator by using the terahertz CUR (THz-CUR) source based on an extremely short electron bunch at Research Center for Electron Photon Science (ELPH), Tohoku University. The horizontally polarized CUR with a frequency of 1.9 THz was manipulated into variable polarization state, and Stokes parameters were measured to derive the degree of polarization. Beam experimental results will be presented in this conference.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOJO18
About •	Received ※ 09 September 2022 — Revised ※ 18 September 2022 — Accepted ※ 21 September 2022 — Issue date ※ 12 October 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOJO19	Programmable SLED System for Single Bunch and Multibunch Linac Operation	73
	C. Christou, P. Gu, A. Tropp DLS, Oxfordshire, United Kingdom
	The Diamond Light Source pre-injector linac generates single bunch and multibunch 100 MeV electron beams for top-up and fill of the storage ring. The linac is powered by two high-power 3 GHz klystrons, and both klystrons are required for reliable injection into the booster and storage ring. In order to introduce redundancy, a SLED pulse compression cavity has been installed so that the linac can operate from just one klystron, with the second klystron held as a standby. A simple phase flip can be used to generate a high-power transient RF spike, suitable for single bunch linac operation, and a programmable amplitude and phase drive profile can be specified to generate a constant-power klystron output suitable for multibunch operation. Details are presented of design, installation and high-power operation of the SLED system, and the ability to generate a long pulse, including corrections for klystron nonlinearity and deviations from modulator flat-top, is demonstrated.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOJO19
About •	Received ※ 09 August 2022 — Revised ※ 29 August 2022 — Accepted ※ 02 September 2022 — Issue date ※ 08 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Manipulation and Measurement of Polarization State for THz Coherent Undulator Radiation

69

S. Kashiwagi, H. Hama, F. Hinode, T. Muto, I. Nagasawa, K. Nanbu, H. Saito
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
A. Irizawa
ISIR, Osaka, Japan
H. Zen
Kyoto University, Kyoto, Japan

We are developing an accelerator-based terahertz source that can produce arbitrary polarization states from linearly polarized coherent undulator radiation (CUR). The polarization manipulation of the CUR can be realized using the Martin’Puplett interferometer employed as an optical phase shifter. This study also demonstrates a variable polarization manipulator by using the terahertz CUR (THz-CUR) source based on an extremely short electron bunch at Research Center for Electron Photon Science (ELPH), Tohoku University. The horizontally polarized CUR with a frequency of 1.9 THz was manipulated into variable polarization state, and Stokes parameters were measured to derive the degree of polarization. Beam experimental results will be presented in this conference.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOJO18

About •

Received ※ 09 September 2022 — Revised ※ 18 September 2022 — Accepted ※ 21 September 2022 — Issue date ※ 12 October 2022

Cite •

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

MOPOJO19

Programmable SLED System for Single Bunch and Multibunch Linac Operation

73

C. Christou, P. Gu, A. Tropp
DLS, Oxfordshire, United Kingdom

The Diamond Light Source pre-injector linac generates single bunch and multibunch 100 MeV electron beams for top-up and fill of the storage ring. The linac is powered by two high-power 3 GHz klystrons, and both klystrons are required for reliable injection into the booster and storage ring. In order to introduce redundancy, a SLED pulse compression cavity has been installed so that the linac can operate from just one klystron, with the second klystron held as a standby. A simple phase flip can be used to generate a high-power transient RF spike, suitable for single bunch linac operation, and a programmable amplitude and phase drive profile can be specified to generate a constant-power klystron output suitable for multibunch operation. Details are presented of design, installation and high-power operation of the SLED system, and the ability to generate a long pulse, including corrections for klystron nonlinearity and deviations from modulator flat-top, is demonstrated.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOJO19

About •

Received ※ 09 August 2022 — Revised ※ 29 August 2022 — Accepted ※ 02 September 2022 — Issue date ※ 08 September 2022

Cite •

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