SRF2021 - List of Authors (Jung, Y.)

Paper	Title	Page
THPCAV002	Low Temperature Heat Treatment on the HWR Cavity	779
	Y. Jung, H. Jang, H. Kim, H. Kim, J.W. Kim, M.S. Kim, J. Lee, M. Lee IBS, Daejeon, Republic of Korea S. Jeon Kyungpook National University, Daegu, Republic of Korea
	Institute for Basic Science have been constructing Superconducting LINAC composed of quarter wave resonator (QWR) and half wave resonator (HWR). All QWR cavities have been completely fabricated and successfully tested to be assembled in QWR cryomodules. For now, we have been testing HWR cavities over 50%. For the testing period, the success rate experienced up and downs like we went through during the QWR tests. In many cases, we observed that some cavities did not reach requirement performance 2K although they showed high performance at 4K. We increased the temperature of heat treatment to cure the rapid Q drop at the high gradient and observed most cavities passed the test after heat treatment.
	Poster THPCAV002 [1.979 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-THPCAV002
About •	Received ※ 21 June 2021 — Revised ※ 25 August 2021 — Accepted ※ 22 November 2021 — Issue date ※ 23 February 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPTEV008	Development of a Digital LLRF System for SRF Cavities in RAON Accelerator	845
	H. Jang, D.H. Gil, Y. Jung, H. Kim, Y. Kim, M. Lee IBS, Daejeon, Republic of Korea
	An ion accelerator, RAON is planned and under construction in Daejeon, Korea by Rare Isotope Science Project (RISP) team in Institute of Basic Science (IBS). The purpose of this accelerator is the generation of rare isotope by ISOL (Isotope Separation On-Line) and IF (In-flight Fragmentation) method. To achieve this goal RAON adopted the superconducting cavities at three different frequency (81.25 MHz, 162.5 MHz and 325 MHz) and their RF field will be controlled independently for the acceleration of ions with various A/q. A solid state power amplifier and a low level RF (LLRF) controller pairs are under development to generate and to control the RF for the cavities. Recently the development and evaluation of the digital-based LLRF have been performed. For the operation and test of SRF cavities, self-excited loop (SEL) and generator-driven-resonator (GDR) algorithm is digitally implemented and its test was performed. In this paper the status and test result of RAON LLRF controller will be described.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-THPTEV008
About •	Received ※ 21 June 2021 — Revised ※ 30 August 2021 — Accepted ※ 26 September 2021 — Issue date ※ 23 November 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Low Temperature Heat Treatment on the HWR Cavity

779

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

Institute for Basic Science have been constructing Superconducting LINAC composed of quarter wave resonator (QWR) and half wave resonator (HWR). All QWR cavities have been completely fabricated and successfully tested to be assembled in QWR cryomodules. For now, we have been testing HWR cavities over 50%. For the testing period, the success rate experienced up and downs like we went through during the QWR tests. In many cases, we observed that some cavities did not reach requirement performance 2K although they showed high performance at 4K. We increased the temperature of heat treatment to cure the rapid Q drop at the high gradient and observed most cavities passed the test after heat treatment.

Poster THPCAV002 [1.979 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-THPCAV002

About •

Received ※ 21 June 2021 — Revised ※ 25 August 2021 — Accepted ※ 22 November 2021 — Issue date ※ 23 February 2022

Cite •

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

THPTEV008

Development of a Digital LLRF System for SRF Cavities in RAON Accelerator

845

H. Jang, D.H. Gil, Y. Jung, H. Kim, Y. Kim, M. Lee
IBS, Daejeon, Republic of Korea

An ion accelerator, RAON is planned and under construction in Daejeon, Korea by Rare Isotope Science Project (RISP) team in Institute of Basic Science (IBS). The purpose of this accelerator is the generation of rare isotope by ISOL (Isotope Separation On-Line) and IF (In-flight Fragmentation) method. To achieve this goal RAON adopted the superconducting cavities at three different frequency (81.25 MHz, 162.5 MHz and 325 MHz) and their RF field will be controlled independently for the acceleration of ions with various A/q. A solid state power amplifier and a low level RF (LLRF) controller pairs are under development to generate and to control the RF for the cavities. Recently the development and evaluation of the digital-based LLRF have been performed. For the operation and test of SRF cavities, self-excited loop (SEL) and generator-driven-resonator (GDR) algorithm is digitally implemented and its test was performed. In this paper the status and test result of RAON LLRF controller will be described.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-THPTEV008

About •

Received ※ 21 June 2021 — Revised ※ 30 August 2021 — Accepted ※ 26 September 2021 — Issue date ※ 23 November 2021

Cite •

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