IPAC2022 - List of Authors (Feng, G.)

Paper	Title	Page
TUPOTK065	Design of a Passive Superconducting Harmonic Cavity for HALF Storage Ring	1378
	Y. Wei, B. Du, G. Feng, D. Jia, J. Pang, S.C. Zhang USTC/NSRL, Hefei, Anhui, People’s Republic of China C.P. Welsch, H.D. Zhang The University of Liverpool, Liverpool, United Kingdom C.P. Welsch, H.D. Zhang Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Higher harmonic cavities, also known as Landau cavities, have been proposed to improve beam lifetime and provide Landau damping by lengthening the bunch without energy spread for stable operations of present and future low-emittance storage rings. This contribution presents design of a passive superconducting 3rd-harmonic cavity (super-3HC) for the planned Hefei Advanced Light Facility (HALF) at University of Science and Technology of China. It is designed to provide 0.43 MV at 1499.4 MHz for the nominal 2.2 GeV, 350 mA electron beam, and 1.44 MV main RF voltage in storage ring. Through optimizations it has a low R/Q < 45 Ohm, which has potential to achieve a good bunch lengthening. Higher-order-modes are strongly damped using a pair of room-temperature silicon carbide (SiC) rings to meet the requirement of beam instabilities. In addition, preliminary engineering design for the super-3HC cryomodule is also described in this contribution.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK065
About •	Received ※ 03 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOPT009	Dependency Measurement of BPM Reading in the HLS-II Storage Ring	2580
	G. Wang, K.M. Chen, G. Feng, M. Hosaka, Z. Wang, W. Xu USTC/NSRL, Hefei, Anhui, People’s Republic of China L. Guo Nagoya University, Nagoya, Japan S.W. Wang DLS, Oxfordshire, United Kingdom
	Beam orbit stability is essential for the operation of the storage ring based light sources. Orbit feedback systems are commonly adopted to maintain the beam on a reference orbit. However, the BPM reading could be affected by its temperature, beam current, etc, which leads to shift of the beam reference orbit. Online experiment is carried out in the HLS-II storage ring to study the dependence of the beam reference orbit on the BPM temperature and beam current. The result shows that the average change of BPM readings due to BPM temperature is about 37.4 ’m/’C horizontally and 11.5 ’m/’C vertically. The average change of BPM readings induced by beam current is about 0.27 ’m/mA horizontally and 0.20 ’m/mA vertically.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT009
About •	Received ※ 19 May 2022 — Revised ※ 23 June 2022 — Accepted ※ 27 June 2022 — Issue date ※ 28 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Design of a Passive Superconducting Harmonic Cavity for HALF Storage Ring

1378

Y. Wei, B. Du, G. Feng, D. Jia, J. Pang, S.C. Zhang
USTC/NSRL, Hefei, Anhui, People’s Republic of China
C.P. Welsch, H.D. Zhang
The University of Liverpool, Liverpool, United Kingdom
C.P. Welsch, H.D. Zhang
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Higher harmonic cavities, also known as Landau cavities, have been proposed to improve beam lifetime and provide Landau damping by lengthening the bunch without energy spread for stable operations of present and future low-emittance storage rings. This contribution presents design of a passive superconducting 3rd-harmonic cavity (super-3HC) for the planned Hefei Advanced Light Facility (HALF) at University of Science and Technology of China. It is designed to provide 0.43 MV at 1499.4 MHz for the nominal 2.2 GeV, 350 mA electron beam, and 1.44 MV main RF voltage in storage ring. Through optimizations it has a low R/Q < 45 Ohm, which has potential to achieve a good bunch lengthening. Higher-order-modes are strongly damped using a pair of room-temperature silicon carbide (SiC) rings to meet the requirement of beam instabilities. In addition, preliminary engineering design for the super-3HC cryomodule is also described in this contribution.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK065

About •

Received ※ 03 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022

Cite •

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

THPOPT009

Dependency Measurement of BPM Reading in the HLS-II Storage Ring

2580

G. Wang, K.M. Chen, G. Feng, M. Hosaka, Z. Wang, W. Xu
USTC/NSRL, Hefei, Anhui, People’s Republic of China
L. Guo
Nagoya University, Nagoya, Japan
S.W. Wang
DLS, Oxfordshire, United Kingdom

Beam orbit stability is essential for the operation of the storage ring based light sources. Orbit feedback systems are commonly adopted to maintain the beam on a reference orbit. However, the BPM reading could be affected by its temperature, beam current, etc, which leads to shift of the beam reference orbit. Online experiment is carried out in the HLS-II storage ring to study the dependence of the beam reference orbit on the BPM temperature and beam current. The result shows that the average change of BPM readings due to BPM temperature is about 37.4 ’m/’C horizontally and 11.5 ’m/’C vertically. The average change of BPM readings induced by beam current is about 0.27 ’m/mA horizontally and 0.20 ’m/mA vertically.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT009

About •

Received ※ 19 May 2022 — Revised ※ 23 June 2022 — Accepted ※ 27 June 2022 — Issue date ※ 28 June 2022

Cite •

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