LINAC2022 - List of Authors (Kim, H.)

Paper	Title	Page
MOPOPA20	Q Drop Tendency of Half-Wave Resonator Cavity	118
	Y. Jung, H. Jang, H. Kim, H. Kim, J.W. Kim IBS, Daejeon, Republic of Korea S. Jeon Kyungpook National University, Daegu, Republic of Korea
	All HWRs (half-wave resonator superconducting cavities) have been fabricated and installed in the low energy section of the LINAC in IBS. All HWR cavities have been tested (vertical tests, VT) both at 4.2 K and 2.1 K cryogenic surroundings although operating temperature of HWRs is 2.1 K. Good cavities of high quality factors showed the Q drop tendency of 2.1 k were very similar to that of 4.2 K. However, in many cases, Q drop tendency of 2.1 K were not similar with 4.2 K, rather Q decreased more rapidly than 4.2 K which means the surface resistance of the cavity rapidly increased at 2 K surrounding. In this study, we will report that various Q results of HWRs and compare their Q drop tendency as a function of temperature, 2.1 K and 4.2 K.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOPA20
About •	Received ※ 23 August 2022 — Revised ※ 28 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 01 September 2022
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MOPOGE24	Understanding Q Slope of Superconducting Cavity with Magnetic Defect and Field Emission	208
MOOPA07	use link to see paper's listing under its alternate paper code
	H. Kim, Y. Jung, H. Kim, J.W. Kim IBS, Daejeon, Republic of Korea S. Jeon Kyungpook National University, Daegu, Republic of Korea
	Funding: This research was supported by the RISP of ibs funded by the Ministry of Science and the National Research Foundation (NRF) of the Republic of Korea under Contract 2013M7A1A1075764. RF test for quarter-wave resonator (QWR) and half-wave resonator (HWR) superconducting cavities is performed at low temperature. The quality factors of the superconducting cavities are measured as a function of accelerating field. The magnetic heating effect for the quarter-wave resonator (QWR) is studied. For the half-wave resonator (HWR), the Q slope degradation is investigated with x-ray radiation and field emission.
	Slides MOPOGE24 [2.506 MB]
	Poster MOPOGE24 [1.174 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE24
About •	Received ※ 25 July 2022 — Revised ※ 18 August 2022 — Accepted ※ 23 August 2022 — Issue date ※ 12 October 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOGE06	Performance Test of Mass-Production of HWR Cryomodules for SCL32	491
	Y. Kim, J.W. Choi, D.H. Gil, H. Jang, Y.W. Jo, J. Joo, H.C. Jung, H. Kim, M.S. Kim, M. Kwon, M. Lee, J.H. Shin IBS, Daejeon, Republic of Korea Y.U. Sohn PAL, Pohang, Republic of Korea
	Funding: This work was supported by the Rare Isotope Science Project of Institute for Basic Science funded by Ministry of Science and ICT and NRF of Korea (2013M7A1A1075764) Mass production of the HWR (half wave resonator) cryomodules for SCL32 of RAON had been conducted since 2018 and all cryomodules were installed in the SCL3 tunnel in 2021. Total number of the HWR cavities and the HWR cryomodules are 10⁶ and 34, respectively. Cryomodule performance test was started in September 2020 and finished in October 2021, except for one bunching cryomodule that will be installed in front of the high energy linac. The detailed procedure and the results of performance test is reported in detail.
	Poster TUPOGE06 [1.211 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOGE06
About •	Received ※ 14 August 2022 — Revised ※ 23 August 2022 — Accepted ※ 12 September 2022 — Issue date ※ 15 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOPA18	Development of a Tuner Control System for Low-Energy Superconducting Linac at RAON	778
	H. Kim, M.O. Hyun, H. Jang, M.S. Kim, Y. Kim IBS, Daejeon, Republic of Korea
	Funding: This research was supported by the RISP of ibs funded by the Ministry of Science and the National Research Foundation (NRF) of the Republic of Korea under Contract 2013M7A1A1075764. We propose a tuner control system for low-energy superconducting linac at RAON. The frequency error of the superconducting cavities must be smaller than a few of Hz to operate in beam acceleration mode. To minimize the freuqency error as much as possible, the error is calculated in the low-level RF(LLRF), and the proposed tuner control system changes the superconducting cavity frequency by using a mechanical tuner and a motor attached to the cavity directly. This control system deals with not only the initial frequency error of the cavity but also the frequency drift of the cavity induced by external disturbance such as the slow fluctuation helium pressure automatically. In addition, an automatic proportional gain calibration technique is also proposed. In this paper, the detailed operation and techniques will be described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOPA18
About •	Received ※ 13 August 2022 — Revised ※ 23 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 11 September 2022
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Paper

Title

Page

Q Drop Tendency of Half-Wave Resonator Cavity

118

Y. Jung, H. Jang, H. Kim, H. Kim, J.W. Kim
IBS, Daejeon, Republic of Korea
S. Jeon
Kyungpook National University, Daegu, Republic of Korea

All HWRs (half-wave resonator superconducting cavities) have been fabricated and installed in the low energy section of the LINAC in IBS. All HWR cavities have been tested (vertical tests, VT) both at 4.2 K and 2.1 K cryogenic surroundings although operating temperature of HWRs is 2.1 K. Good cavities of high quality factors showed the Q drop tendency of 2.1 k were very similar to that of 4.2 K. However, in many cases, Q drop tendency of 2.1 K were not similar with 4.2 K, rather Q decreased more rapidly than 4.2 K which means the surface resistance of the cavity rapidly increased at 2 K surrounding. In this study, we will report that various Q results of HWRs and compare their Q drop tendency as a function of temperature, 2.1 K and 4.2 K.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOPA20

About •

Received ※ 23 August 2022 — Revised ※ 28 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 01 September 2022

Cite •

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

MOPOGE24

Understanding Q Slope of Superconducting Cavity with Magnetic Defect and Field Emission

208

MOOPA07

use link to see paper's listing under its alternate paper code

H. Kim, Y. Jung, H. Kim, J.W. Kim
IBS, Daejeon, Republic of Korea
S. Jeon
Kyungpook National University, Daegu, Republic of Korea

Funding: This research was supported by the RISP of ibs funded by the Ministry of Science and the National Research Foundation (NRF) of the Republic of Korea under Contract 2013M7A1A1075764.
RF test for quarter-wave resonator (QWR) and half-wave resonator (HWR) superconducting cavities is performed at low temperature. The quality factors of the superconducting cavities are measured as a function of accelerating field. The magnetic heating effect for the quarter-wave resonator (QWR) is studied. For the half-wave resonator (HWR), the Q slope degradation is investigated with x-ray radiation and field emission.

Slides MOPOGE24 [2.506 MB]

Poster MOPOGE24 [1.174 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE24

About •

Received ※ 25 July 2022 — Revised ※ 18 August 2022 — Accepted ※ 23 August 2022 — Issue date ※ 12 October 2022

Cite •

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

TUPOGE06

Performance Test of Mass-Production of HWR Cryomodules for SCL32

491

Y. Kim, J.W. Choi, D.H. Gil, H. Jang, Y.W. Jo, J. Joo, H.C. Jung, H. Kim, M.S. Kim, M. Kwon, M. Lee, J.H. Shin
IBS, Daejeon, Republic of Korea
Y.U. Sohn
PAL, Pohang, Republic of Korea

Funding: This work was supported by the Rare Isotope Science Project of Institute for Basic Science funded by Ministry of Science and ICT and NRF of Korea (2013M7A1A1075764)
Mass production of the HWR (half wave resonator) cryomodules for SCL32 of RAON had been conducted since 2018 and all cryomodules were installed in the SCL3 tunnel in 2021. Total number of the HWR cavities and the HWR cryomodules are 10⁶ and 34, respectively. Cryomodule performance test was started in September 2020 and finished in October 2021, except for one bunching cryomodule that will be installed in front of the high energy linac. The detailed procedure and the results of performance test is reported in detail.

Poster TUPOGE06 [1.211 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOGE06

About •

Received ※ 14 August 2022 — Revised ※ 23 August 2022 — Accepted ※ 12 September 2022 — Issue date ※ 15 September 2022

Cite •

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

THPOPA18

Development of a Tuner Control System for Low-Energy Superconducting Linac at RAON

778

H. Kim, M.O. Hyun, H. Jang, M.S. Kim, Y. Kim
IBS, Daejeon, Republic of Korea

Funding: This research was supported by the RISP of ibs funded by the Ministry of Science and the National Research Foundation (NRF) of the Republic of Korea under Contract 2013M7A1A1075764.
We propose a tuner control system for low-energy superconducting linac at RAON. The frequency error of the superconducting cavities must be smaller than a few of Hz to operate in beam acceleration mode. To minimize the freuqency error as much as possible, the error is calculated in the low-level RF(LLRF), and the proposed tuner control system changes the superconducting cavity frequency by using a mechanical tuner and a motor attached to the cavity directly. This control system deals with not only the initial frequency error of the cavity but also the frequency drift of the cavity induced by external disturbance such as the slow fluctuation helium pressure automatically. In addition, an automatic proportional gain calibration technique is also proposed. In this paper, the detailed operation and techniques will be described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOPA18

About •

Received ※ 13 August 2022 — Revised ※ 23 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 11 September 2022

Cite •

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