COOL2017 - List of Authors (Stassen, R.)

Paper	Title	Page
TUP17	Design of Stochastic Pick-Ups and Kickers for Low Beta Particle Beams	68
	B. Breitkreutz, R. Stassen, H. Stockhorst FZJ, Jülich, Germany
	The COSY facility hosts experiments for the JEDI (Jülich Electric Dipole moment Investigations) collabora-tion. Polarized deuteron beams with a momentum of 970 MeV/c are stored in the ring. To achieve polarization times in the order of several minutes, small emittances and momentum spread are crucial. Therefore, the beam is pre-cooled with the 100-kV electron cooler. To further improve the spin coherence time, cooling during the experiments would be desirable. That way, the beam blow-up due to intra beam scattering could be compen-sated. But since the focusing solenoids in the e-cooler may not be perfectly compensated, it cannot be used to cool during the experiments. The existing stochastic cooling (SC) system is not sensitive at low beam veloci-ties. Thus, it is proposed to build a dedicated SC system for low beta beams. This work presents the proposed sys-tem. It emphasizes the design process of pick-up and kicker hardware. Starting from the slot-ring structures that have been developed for HESR, an optimization towards a high sensitivity at a beta of 0.46 is undertaken.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2017-TUP17
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THA11	The HESR Stochastic Cooling System, Design, Construction and Test Experiments in COSY	89
	R. Stassen, B. Breitkreutz, N. Shurkhno, H. Stockhorst FZJ, Jülich, Germany L. Thorndahl CERN, Geneva, Switzerland
	The construction phase of the stochastic cooling tanks for the HESR has started. Meanwhile two pickups (PU) and one kicker (KI) are fabricated. One PU and one KI are installed into the COSY ring for testing the new stochastic cooling system with real beam at various momenta. Small test-structures were already successfully operated at the Nuclotron in Dubna for longitudinal filter cooling but not for transverse cooling and as small PU in COSY. During the last COSY beam-time in 2017 additional transverse and ToF cooling were achieved. The first two series high power amplifiers were used for cooling and to test the temperature behavior of the combiner-boards at the KI. The system layout includes all components as planned for the HESR like low noise amplifier, switchable delay-lines and optical notch-filter. The HESR needs fast transmission-lines between PU and KI. Beside air-filled coax-lines, optical hollow fiber-lines are very attractive. First results with such a fiber used for the transverse signal path will be presented.
	Slides THA11 [11.863 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2017-THA11
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THA13	Algorithmic Control of Stochastic Cooling Systems
	N. Shurkhno, R. Stassen FZJ, Jülich, Germany
	Adjustment of stochastic cooling systems especially from scratch is usually very tedious and time-consuming, but at the same time it is quite straightforward and therefore could be made fully automatic. The basic parameters one should consider to set-up a stochastic cooling system are system delay and gain, and optionally a notch-filter frequency and attenuation. With proper algorithms the adjustment and control of these parameters could be done to the best accuracy and speed. To achieve this a universal software and hardware solutions were developed, allowing for fast automatic adjustment of stochastic cooling systems as well as for maintaining the adjustment during system operation without maintenance stops or beam disturbance. This report presents the developed approach for the automatic control and adjustment of stochastic cooling systems.
	Slides THA13 [1.549 MB]
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Paper

Title

Page

Design of Stochastic Pick-Ups and Kickers for Low Beta Particle Beams

68

B. Breitkreutz, R. Stassen, H. Stockhorst
FZJ, Jülich, Germany

The COSY facility hosts experiments for the JEDI (Jülich Electric Dipole moment Investigations) collabora-tion. Polarized deuteron beams with a momentum of 970 MeV/c are stored in the ring. To achieve polarization times in the order of several minutes, small emittances and momentum spread are crucial. Therefore, the beam is pre-cooled with the 100-kV electron cooler. To further improve the spin coherence time, cooling during the experiments would be desirable. That way, the beam blow-up due to intra beam scattering could be compen-sated. But since the focusing solenoids in the e-cooler may not be perfectly compensated, it cannot be used to cool during the experiments. The existing stochastic cooling (SC) system is not sensitive at low beam veloci-ties. Thus, it is proposed to build a dedicated SC system for low beta beams. This work presents the proposed sys-tem. It emphasizes the design process of pick-up and kicker hardware. Starting from the slot-ring structures that have been developed for HESR, an optimization towards a high sensitivity at a beta of 0.46 is undertaken.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2017-TUP17

Export •

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

THA11

The HESR Stochastic Cooling System, Design, Construction and Test Experiments in COSY

89

R. Stassen, B. Breitkreutz, N. Shurkhno, H. Stockhorst
FZJ, Jülich, Germany
L. Thorndahl
CERN, Geneva, Switzerland

The construction phase of the stochastic cooling tanks for the HESR has started. Meanwhile two pickups (PU) and one kicker (KI) are fabricated. One PU and one KI are installed into the COSY ring for testing the new stochastic cooling system with real beam at various momenta. Small test-structures were already successfully operated at the Nuclotron in Dubna for longitudinal filter cooling but not for transverse cooling and as small PU in COSY. During the last COSY beam-time in 2017 additional transverse and ToF cooling were achieved. The first two series high power amplifiers were used for cooling and to test the temperature behavior of the combiner-boards at the KI. The system layout includes all components as planned for the HESR like low noise amplifier, switchable delay-lines and optical notch-filter. The HESR needs fast transmission-lines between PU and KI. Beside air-filled coax-lines, optical hollow fiber-lines are very attractive. First results with such a fiber used for the transverse signal path will be presented.

Slides THA11 [11.863 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2017-THA11

Export •

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

THA13

Algorithmic Control of Stochastic Cooling Systems

N. Shurkhno, R. Stassen
FZJ, Jülich, Germany

Adjustment of stochastic cooling systems especially from scratch is usually very tedious and time-consuming, but at the same time it is quite straightforward and therefore could be made fully automatic. The basic parameters one should consider to set-up a stochastic cooling system are system delay and gain, and optionally a notch-filter frequency and attenuation. With proper algorithms the adjustment and control of these parameters could be done to the best accuracy and speed. To achieve this a universal software and hardware solutions were developed, allowing for fast automatic adjustment of stochastic cooling systems as well as for maintaining the adjustment during system operation without maintenance stops or beam disturbance. This report presents the developed approach for the automatic control and adjustment of stochastic cooling systems.

Slides THA13 [1.549 MB]

Export •

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