COOL2023 - List of Authors (Wu, J.X.)

Paper	Title	Page
TUPPM1R2	Development of Stochastic Cooling Components for HIAF Spectrometer Ring	22
	G. Zhu, Z. Du, J.X. Wu, J. Yin IMP/CAS, Lanzhou, People’s Republic of China L.Y. Ma NWNU, Lanzhou, Gansu, People’s Republic of China
	Stochastic cooling of the spectrometer ring (SRing) with the bandwidth of 0.6-1.2 GHz at the High Intensity Heavy-Ion Accelerator Facility (HIAF) project in China, which is used mainly for experiments with radioactive fragment beams, is applied to speed up the cooling process of a stored ion beam. In this paper, both the prototypes of coaxial notch filter with amplitude equalizer and optical notch filter with phase-stabilized optical fiber cable are built and measured for SRing stochastic cooling system. A 9 bit wide-band 360° digital adjustable phase shifter with minimum step length of 0.7° has been fabricated and tested for HIAF stochastic cooling. Meanwhile, the prototype of RF signal transmission processing units of SRing stochastic cooling are measured. Finally, the development, performance, and testing of both a Faltin prototype traveling wave structure and a novel slot-ring prototype standing wave structure based on a ceramic vacuum chamber for the HIAF SRing stochastic cooling system are discussed briefly.
	Slides TUPPM1R2 [8.642 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-COOL2023-TUPPM1R2
About •	Received ※ 10 October 2023 — Revised ※ 11 October 2023 — Accepted ※ 20 November 2023 — Issued ※ 02 December 2023
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TUPPM2R1	Laser cooling of bunched O⁵⁺ ion beams at the CSRe: investigation of coherent effect and extraction of momentum distribution from Schottky spectrum
	H.B. Wang, D.Y. Chen, Z. Huang, X. Ma, L.J. Mao, W.Q. Wen, J.X. Wu, J.C. Yang, Y.J. Yuan, S.F. Zhang IMP/CAS, Lanzhou, People’s Republic of China M.H. Bussmann CASUS, Görlitz, Germany D. Kiefer, T. Walther TU Darmstadt, Darmstadt, Germany S. Klammes, D.F.A. Winters GSI, Darmstadt, Germany M. Löser, M. Siebold HZDR, Dresden, Germany U. Schramm Technische Universität Dresden, Dresden, Germany D. Zhang Xidian University, Xi’an, People’s Republic of China
	Laser cooling of O⁵⁺ ion beams with an energy of 275.7 MeV/u was achieved at the storage ring CSRe in Lanzhou, China [1]. In the experiment, the momentum distribution was measured by the Schottky resonator. Besides, a multi-particle tracking method has been developed to simulate the Schottky spectra of bunched ion beams. We systematically studied the dependence of the Schottky power on the number of stored ions at different bunching and observation harmonics. The central peak is coherently enlarged only when the observation harmonic is an integer multiple of the bunching harmonic. The reason is that the randomness of the phase for each ion disappears at this condition, thus all ions coherently contribute to the Schottky power (Pcenter-N²). Therefore, the greatly enhanced central peak, caused by the "coherent effect", has been fully interpreted for the first time. Besides, we propose a new method to extract the momentum distribution from the Schottky spectrum of the bunched ion beams. Unlike the previously used methods [2], this is a very simple and precise way to obtain momentum distribution in real-time for bunched ion beams during beam cooling experiments. [1] W.Q. Wen, Hyperfine Interact. 240, 45 (2019); [2] M. Bussmann, Proceedings of COOL 2007, 226-229; K. Lasocha, PRAB 23 (2020) 062803; V. Balbekov, Proceedings of EPAC 2004, Lucerne, Switzerland.
	Slides TUPPM2R1 [8.987 MB]
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THPOSRP19	Simulation of Broadband Laser Cooling of Relativistic Ion Beams at the Csre
	D.Y. Chen, Z. Huang, X. Ma, L.J. Mao, H.B. Wang, W.Q. Wen, J.X. Wu, J.C. Yang, Y.J. Yuan, S.F. Zhang IMP/CAS, Lanzhou, People’s Republic of China M.H. Bussmann CASUS, Görlitz, Germany D. Kiefer, T. Walther TU Darmstadt, Darmstadt, Germany S. Klammes, D.F.A. Winters GSI, Darmstadt, Germany M. Löser, M. Siebold HZDR, Dresden, Germany U. Schramm Technische Universität Dresden, Dresden, Germany D. Zhang Xidian University, Xi’an, People’s Republic of China
	Laser cooling of a bunched relativistic O⁵⁺ ion beam with a cw laser has been demonstrated at the CSRe [1]. The relative momentum spread of the cooled beams has reached 2×10^-6. But laser cooling does efficiently cool the ions only within a narrow velocity class due to the narrow linewidth of the cw laser, one thus needs to scan the laser frequency relative to the rf-frequency to cool all ions [2]. To extend the acceptance of the laser force, we are planning to utilize a pulsed laser that combines with the cw laser to achieve broadband laser cooling. The pulsed laser enables simultaneous interaction with a broad velocity classes ions and the cw laser can cool the ions to lower temperatures. It should be noted that laser cooling of relativistic C³⁺ ion beams using a pulsed laser was successfully investigated at the ESR recently [3]. To study the beam cooling procedures, simulations of the cooling dynamics under different conditions are being performed based on our newly developed simulation code [4]. Through simulations, the optimal conditions for achieving efficient beam cooling will be determined to guide the successful implementation of the broadband laser cooling experiments. [1] W.Q. Wen et al., to be submitted. [2] M. Bussmann et al., J. Phys: Conf. Ser. 88 (2007) 012043. [3] S. Klammes et al., COOL2023 conference. [4] D.Y. Chen et al., NIMA 1047 (2023) 167852.
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Paper

Title

Page

Development of Stochastic Cooling Components for HIAF Spectrometer Ring

22

G. Zhu, Z. Du, J.X. Wu, J. Yin
IMP/CAS, Lanzhou, People’s Republic of China
L.Y. Ma
NWNU, Lanzhou, Gansu, People’s Republic of China

Stochastic cooling of the spectrometer ring (SRing) with the bandwidth of 0.6-1.2 GHz at the High Intensity Heavy-Ion Accelerator Facility (HIAF) project in China, which is used mainly for experiments with radioactive fragment beams, is applied to speed up the cooling process of a stored ion beam. In this paper, both the prototypes of coaxial notch filter with amplitude equalizer and optical notch filter with phase-stabilized optical fiber cable are built and measured for SRing stochastic cooling system. A 9 bit wide-band 360° digital adjustable phase shifter with minimum step length of 0.7° has been fabricated and tested for HIAF stochastic cooling. Meanwhile, the prototype of RF signal transmission processing units of SRing stochastic cooling are measured. Finally, the development, performance, and testing of both a Faltin prototype traveling wave structure and a novel slot-ring prototype standing wave structure based on a ceramic vacuum chamber for the HIAF SRing stochastic cooling system are discussed briefly.

Slides TUPPM1R2 [8.642 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-COOL2023-TUPPM1R2

About •

Received ※ 10 October 2023 — Revised ※ 11 October 2023 — Accepted ※ 20 November 2023 — Issued ※ 02 December 2023

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

TUPPM2R1

Laser cooling of bunched O⁵⁺ ion beams at the CSRe: investigation of coherent effect and extraction of momentum distribution from Schottky spectrum

H.B. Wang, D.Y. Chen, Z. Huang, X. Ma, L.J. Mao, W.Q. Wen, J.X. Wu, J.C. Yang, Y.J. Yuan, S.F. Zhang
IMP/CAS, Lanzhou, People’s Republic of China
M.H. Bussmann
CASUS, Görlitz, Germany
D. Kiefer, T. Walther
TU Darmstadt, Darmstadt, Germany
S. Klammes, D.F.A. Winters
GSI, Darmstadt, Germany
M. Löser, M. Siebold
HZDR, Dresden, Germany
U. Schramm
Technische Universität Dresden, Dresden, Germany
D. Zhang
Xidian University, Xi’an, People’s Republic of China

Laser cooling of O⁵⁺ ion beams with an energy of 275.7 MeV/u was achieved at the storage ring CSRe in Lanzhou, China [1]. In the experiment, the momentum distribution was measured by the Schottky resonator. Besides, a multi-particle tracking method has been developed to simulate the Schottky spectra of bunched ion beams. We systematically studied the dependence of the Schottky power on the number of stored ions at different bunching and observation harmonics. The central peak is coherently enlarged only when the observation harmonic is an integer multiple of the bunching harmonic. The reason is that the randomness of the phase for each ion disappears at this condition, thus all ions coherently contribute to the Schottky power (Pcenter-N²). Therefore, the greatly enhanced central peak, caused by the "coherent effect", has been fully interpreted for the first time. Besides, we propose a new method to extract the momentum distribution from the Schottky spectrum of the bunched ion beams. Unlike the previously used methods [2], this is a very simple and precise way to obtain momentum distribution in real-time for bunched ion beams during beam cooling experiments.
[1] W.Q. Wen, Hyperfine Interact. 240, 45 (2019);
[2] M. Bussmann, Proceedings of COOL 2007, 226-229; K. Lasocha, PRAB 23 (2020) 062803; V. Balbekov, Proceedings of EPAC 2004, Lucerne, Switzerland.

Slides TUPPM2R1 [8.987 MB]

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THPOSRP19

Simulation of Broadband Laser Cooling of Relativistic Ion Beams at the Csre

D.Y. Chen, Z. Huang, X. Ma, L.J. Mao, H.B. Wang, W.Q. Wen, J.X. Wu, J.C. Yang, Y.J. Yuan, S.F. Zhang
IMP/CAS, Lanzhou, People’s Republic of China
M.H. Bussmann
CASUS, Görlitz, Germany
D. Kiefer, T. Walther
TU Darmstadt, Darmstadt, Germany
S. Klammes, D.F.A. Winters
GSI, Darmstadt, Germany
M. Löser, M. Siebold
HZDR, Dresden, Germany
U. Schramm
Technische Universität Dresden, Dresden, Germany
D. Zhang
Xidian University, Xi’an, People’s Republic of China

Laser cooling of a bunched relativistic O⁵⁺ ion beam with a cw laser has been demonstrated at the CSRe [1]. The relative momentum spread of the cooled beams has reached 2×10^-6. But laser cooling does efficiently cool the ions only within a narrow velocity class due to the narrow linewidth of the cw laser, one thus needs to scan the laser frequency relative to the rf-frequency to cool all ions [2]. To extend the acceptance of the laser force, we are planning to utilize a pulsed laser that combines with the cw laser to achieve broadband laser cooling. The pulsed laser enables simultaneous interaction with a broad velocity classes ions and the cw laser can cool the ions to lower temperatures. It should be noted that laser cooling of relativistic C³⁺ ion beams using a pulsed laser was successfully investigated at the ESR recently [3]. To study the beam cooling procedures, simulations of the cooling dynamics under different conditions are being performed based on our newly developed simulation code [4]. Through simulations, the optimal conditions for achieving efficient beam cooling will be determined to guide the successful implementation of the broadband laser cooling experiments.
[1] W.Q. Wen et al., to be submitted.
[2] M. Bussmann et al., J. Phys: Conf. Ser. 88 (2007) 012043.
[3] S. Klammes et al., COOL2023 conference.
[4] D.Y. Chen et al., NIMA 1047 (2023) 167852.

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