COOL2023 - Classification: Stochastic cooling

Paper	Title	Page
TUPPM1R1	Stochastic Cooling of Electrons and Positrons with EUV Light
	A.A. Zholents ANL, Lemont, Illinois, USA
	Funding: Supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02- 06CH11357. Stochastic cooling of electrons and positrons using their extreme ultraviolet radiation is considered. A few beneficial modifications of a stochastic cooling technique are described – a petaherz-scale bandwidth, ability to apply many uncorrelated corrections to particle offsets in one cooling system, cascade amplified stochastic cooling – all resulting in a simpler and more flexible cooling system producing fast cooling without the amplifier. This approach to cooling electron and positron beams easily outperforms radiation cooling in preparing low-emittance and low-energy-spread beams in moderate-energy storage rings. An option for using this technique to maintain a "cold" electron beam for an electron cooling of protons in Electron Ion Collider is considered.
	Slides TUPPM1R1 [2.665 MB]
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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
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPPM1R3	Numerical Study of the Wiggler-Based Microbunching Amplifier for EIC	26
	A.A. Zholents ANL, Lemont, Illinois, USA C.C. Hall RadiaSoft LLC, Boulder, Colorado, USA
	Funding: Supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02- 06CH11357. Coherent electron cooling* using a plasma-cascade amplifier (PCA) can provide significantly faster cooling of hadrons than the conventional microwave stochastic cooling due to a wide bandwidth of a pickup, a kicker, and an amplifier. The PCA creates unstable plasma oscillations by modulating the plasma frequency by varying the transverse beam size along the beam line. An alternative approach to the amplifier studied in this work is to modulate the plasma frequency by a sequence of wiggler magnets separated by weak chicanes. We present a new derivation of the amplifier spectral gain function following the initial analysis presented in . Numerical simulations of the gain function were also done using electron beam parameters projected for the Electron Ion Collider. The numerical results consistently show higher gains than those obtained using the analytical gain function. V. Litvinenko, Ya. Derbenev, Phys. Rev. Lett., 102, (2009)114801. V. Litvinenko et al., Phys. Rev. Accel. Beams, 24, (2021)014402. * G. Stupakov, A. Zholents, COOL2021
	Slides TUPPM1R3 [3.136 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-COOL2023-TUPPM1R3
About •	Received ※ 28 September 2023 — Revised ※ 11 October 2023 — Accepted ※ 13 October 2023 — Issued ※ 02 December 2023
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THPOSRP20	Beam Measurements of a Palmer Pick-up for the Collector Ring of FAIR	95
	C. Peschke, R.M. Böhm, C. Dimopoulou, S. Wunderlich, C. Zhang GSI, Darmstadt, Germany
	The stochastic cooling system of the Collector Ring (CR) of the future FAIR facility will have three pick-up tanks and two kicker tanks. For the pre-cooling of very hot RIBs, a pick-up tank with eight Faltin-type structures for Palmer-cooling has been constructed by GSI. The structures have been designed using High-Frequency Structure Simulator (HFSS). The Palmer PU tank has been tested with β = 0.83 proton beams at the COoler SYnchrotron (COSY) of the FZJ. This publication will present the results of measurements with beam and compare them with simulations (HFSS and Microwave Studio). The pick-up operates at room temperature. But it has artificial cold loads instead of normal terminators. The results of the noise temperature measurements will also be presented.
	Poster THPOSRP20 [2.699 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-COOL2023-THPOSRP20
About •	Received ※ 06 October 2023 — Revised ※ 11 October 2023 — Accepted ※ 12 October 2023 — Issued ※ 02 December 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOSRP21	How to Adjust Stochastic Cooling Systems	98
	N. Shurkhno GSI, Darmstadt, Germany
	The paper summarizes techniques and algorithms for adjustment of stochastic cooling systems, that have been developed and tested at the COSY accelerator facility (FZ Jülich, Germany). An overall goal was to automate typical time-consuming manual adjustment routines. As a result, a set of algorithms based on a Fokker-Planck description of stochastic cooling process was developed, which allow an accurate and fast automatic adjustment of main system’s parameters. The methods have been elaborated and used at COSY during development and testing of stochastic cooling systems for HESR and are planned for further use at the FAIR accelerator complex (GSI, Germany). The methods are quite universal and can be applied or adapted to any similar system.
	Poster THPOSRP21 [0.786 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-COOL2023-THPOSRP21
About •	Received ※ 17 October 2023 — Revised ※ 26 October 2023 — Accepted ※ 14 November 2023 — Issued ※ 02 December 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOSRP22	Experience with Beam Transfer Function Measurements for Setting-up the Stochastic Cooling System in the CERN Anti-Proton Decelerator (AD)	102
	S.F. Rey, W.B. Bastos, F. Caspers, B. Dupuy, D. Gamba, W. Höfle, R. Louwerse CERN, Meyrin, Switzerland
	Beam transfer function measurements have regularly been used to set-up the adjustable parameters for stochastic cooling systems. We report on the automation of these measurements at CERN that permit efficient set-up of the cooling loops in the anti-proton decelerator (AD) and enables insight into the bandwidth (nominal frequency range of 850 MHz to 1.7 GHz) of the overall system for the longitudinal, horizontal and vertical cooling at the two different beam momenta of 2 GeV/c and 3.5 GeV/c. Data collected in machine development sessions can be used to identify areas of improvement and will be indispensable in defining the planned path for consolidation and upgrade of the system. It allows the comparison of the bandwidth with the computed shunt impedance of the currently used kickers. The unwanted interplay between the three different planes of cooling is also evaluated and will help to define improvements in the system for the future.
	Poster THPOSRP22 [0.905 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-COOL2023-THPOSRP22
About •	Received ※ 23 October 2023 — Revised ※ 14 November 2023 — Accepted ※ 21 November 2023 — Issued ※ 02 December 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOSRP23	Kicker for the CR Stochastic Cooling System Based on HESR Slot-Ring Coupler	106
	R. Stassen, R. Greven, H. Schneider, J. Wolters FZJ, Jülich, Germany B. Breitkreutz GSI, Darmstadt, Germany
	A ’light’ version of the HESR stochastic cooling system was already successfully tested in the Cooler Synchrotron COSY. There the stochastic cooling was operated together with the original PANDA cluster jet target from University Münster. The system layout includes all components as planned for the HESR like low noise amplifier, switchable delay-lines and optical notch-filter. The robust split ring design has been proven itself. Hence it was decided to use this concept for the CR kicker as well. Therefore the parameters need to be adapted for the CR cooling system. However, the significantly higher RF power requires a new cooling concept for the heat dissipated in the divider board resistors. First simulations and measurements show that using heat pipes could be a possible solution. At COOL23 main parameter as well as the promising results will be presented.
DOI •	reference for this paper ※ doi:10.18429/JACoW-COOL2023-THPOSRP23
About •	Received ※ 20 September 2023 — Revised ※ 10 October 2023 — Accepted ※ 21 November 2023 — Issued ※ 02 December 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

TUPPM1R1

Stochastic Cooling of Electrons and Positrons with EUV Light

A.A. Zholents
ANL, Lemont, Illinois, USA

Funding: Supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02- 06CH11357.
Stochastic cooling of electrons and positrons using their extreme ultraviolet radiation is considered. A few beneficial modifications of a stochastic cooling technique are described – a petaherz-scale bandwidth, ability to apply many uncorrelated corrections to particle offsets in one cooling system, cascade amplified stochastic cooling – all resulting in a simpler and more flexible cooling system producing fast cooling without the amplifier. This approach to cooling electron and positron beams easily outperforms radiation cooling in preparing low-emittance and low-energy-spread beams in moderate-energy storage rings. An option for using this technique to maintain a "cold" electron beam for an electron cooling of protons in Electron Ion Collider is considered.

Slides TUPPM1R1 [2.665 MB]

Cite •

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

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

Cite •

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

TUPPM1R3

Numerical Study of the Wiggler-Based Microbunching Amplifier for EIC

26

A.A. Zholents
ANL, Lemont, Illinois, USA
C.C. Hall
RadiaSoft LLC, Boulder, Colorado, USA

Funding: Supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02- 06CH11357.
Coherent electron cooling* using a plasma-cascade amplifier (PCA)** can provide significantly faster cooling of hadrons than the conventional microwave stochastic cooling due to a wide bandwidth of a pickup, a kicker, and an amplifier. The PCA creates unstable plasma oscillations by modulating the plasma frequency by varying the transverse beam size along the beam line. An alternative approach to the amplifier studied in this work is to modulate the plasma frequency by a sequence of wiggler magnets separated by weak chicanes. We present a new derivation of the amplifier spectral gain function following the initial analysis presented in ***. Numerical simulations of the gain function were also done using electron beam parameters projected for the Electron Ion Collider. The numerical results consistently show higher gains than those obtained using the analytical gain function.
* V. Litvinenko, Ya. Derbenev, Phys. Rev. Lett., 102, (2009)114801.
** V. Litvinenko et al., Phys. Rev. Accel. Beams, 24, (2021)014402.
*** G. Stupakov, A. Zholents, COOL2021

Slides TUPPM1R3 [3.136 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-COOL2023-TUPPM1R3

About •

Received ※ 28 September 2023 — Revised ※ 11 October 2023 — Accepted ※ 13 October 2023 — Issued ※ 02 December 2023

Cite •

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

THPOSRP20

Beam Measurements of a Palmer Pick-up for the Collector Ring of FAIR

95

C. Peschke, R.M. Böhm, C. Dimopoulou, S. Wunderlich, C. Zhang
GSI, Darmstadt, Germany

The stochastic cooling system of the Collector Ring (CR) of the future FAIR facility will have three pick-up tanks and two kicker tanks. For the pre-cooling of very hot RIBs, a pick-up tank with eight Faltin-type structures for Palmer-cooling has been constructed by GSI. The structures have been designed using High-Frequency Structure Simulator (HFSS). The Palmer PU tank has been tested with β = 0.83 proton beams at the COoler SYnchrotron (COSY) of the FZJ. This publication will present the results of measurements with beam and compare them with simulations (HFSS and Microwave Studio). The pick-up operates at room temperature. But it has artificial cold loads instead of normal terminators. The results of the noise temperature measurements will also be presented.

Poster THPOSRP20 [2.699 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-COOL2023-THPOSRP20

About •

Received ※ 06 October 2023 — Revised ※ 11 October 2023 — Accepted ※ 12 October 2023 — Issued ※ 02 December 2023

Cite •

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

THPOSRP21

How to Adjust Stochastic Cooling Systems

98

N. Shurkhno
GSI, Darmstadt, Germany

The paper summarizes techniques and algorithms for adjustment of stochastic cooling systems, that have been developed and tested at the COSY accelerator facility (FZ Jülich, Germany). An overall goal was to automate typical time-consuming manual adjustment routines. As a result, a set of algorithms based on a Fokker-Planck description of stochastic cooling process was developed, which allow an accurate and fast automatic adjustment of main system’s parameters. The methods have been elaborated and used at COSY during development and testing of stochastic cooling systems for HESR and are planned for further use at the FAIR accelerator complex (GSI, Germany). The methods are quite universal and can be applied or adapted to any similar system.

Poster THPOSRP21 [0.786 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-COOL2023-THPOSRP21

About •

Received ※ 17 October 2023 — Revised ※ 26 October 2023 — Accepted ※ 14 November 2023 — Issued ※ 02 December 2023

Cite •

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

THPOSRP22

Experience with Beam Transfer Function Measurements for Setting-up the Stochastic Cooling System in the CERN Anti-Proton Decelerator (AD)

102

S.F. Rey, W.B. Bastos, F. Caspers, B. Dupuy, D. Gamba, W. Höfle, R. Louwerse
CERN, Meyrin, Switzerland

Beam transfer function measurements have regularly been used to set-up the adjustable parameters for stochastic cooling systems. We report on the automation of these measurements at CERN that permit efficient set-up of the cooling loops in the anti-proton decelerator (AD) and enables insight into the bandwidth (nominal frequency range of 850 MHz to 1.7 GHz) of the overall system for the longitudinal, horizontal and vertical cooling at the two different beam momenta of 2 GeV/c and 3.5 GeV/c. Data collected in machine development sessions can be used to identify areas of improvement and will be indispensable in defining the planned path for consolidation and upgrade of the system. It allows the comparison of the bandwidth with the computed shunt impedance of the currently used kickers. The unwanted interplay between the three different planes of cooling is also evaluated and will help to define improvements in the system for the future.

Poster THPOSRP22 [0.905 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-COOL2023-THPOSRP22

About •

Received ※ 23 October 2023 — Revised ※ 14 November 2023 — Accepted ※ 21 November 2023 — Issued ※ 02 December 2023

Cite •

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

THPOSRP23

Kicker for the CR Stochastic Cooling System Based on HESR Slot-Ring Coupler

106

R. Stassen, R. Greven, H. Schneider, J. Wolters
FZJ, Jülich, Germany
B. Breitkreutz
GSI, Darmstadt, Germany

A ’light’ version of the HESR stochastic cooling system was already successfully tested in the Cooler Synchrotron COSY. There the stochastic cooling was operated together with the original PANDA cluster jet target from University Münster. The system layout includes all components as planned for the HESR like low noise amplifier, switchable delay-lines and optical notch-filter. The robust split ring design has been proven itself. Hence it was decided to use this concept for the CR kicker as well. Therefore the parameters need to be adapted for the CR cooling system. However, the significantly higher RF power requires a new cooling concept for the heat dissipated in the divider board resistors. First simulations and measurements show that using heat pipes could be a possible solution. At COOL23 main parameter as well as the promising results will be presented.

DOI •

reference for this paper ※ doi:10.18429/JACoW-COOL2023-THPOSRP23

About •

Received ※ 20 September 2023 — Revised ※ 10 October 2023 — Accepted ※ 21 November 2023 — Issued ※ 02 December 2023

Cite •

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