IPAC2017 - List of Authors (Breitkreutz, B.)

Paper	Title	Page
TUPVA080	Stochastic Cooling Hardware for Low Energy Deuterons at COSY	2261
	B. Breitkreutz, R. Greven, N. Shurkhno, R. Stassen, H. Stockhorst FZJ, Jülich, Germany
	One of the central utilizations of the COSY facility nowadays is to host experiments for the JEDI (Jülich Electric Dipole moment Investigations) collaboration. These experiments use polarized deuteron beams at momenta below 1 GeV/c, that are stored for several minutes. In order to increase the spin coherence time, beam cooling is necessary. Electron cooling is applied to pre-cool the beam, but the solenoids of the electron cooler may not be perfectly compensated. Thus, stochastic cooling would be desirable instead. Unfortunately, the existing stochastic cooling system is not sensitive at low beam velocities. This paper presents newly developed stochastic cooling pickups and kickers for a system dedicated to low beam velocities of approximately 0.5c. The design is based on the slot-ring type pickups that have been developed for the High Energy Storage Ring (HESR), but optimized for low particle velocities and a low frequency band of 350-700 MHz. Since the structures get much bigger in comparison to the HESR version, mechanical properties must be reconsidered and a trade-off between electrical properties, cooling performance and constructability must be found.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA080
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TUPVA085	First Experiences with HESR Stochastic Cooling System	2278
	R. Stassen, B. Breitkreutz, T. Katayama, N. Shurkhno, H. Stockhorst FZJ, Jülich, Germany T. Katayama Nihon University, Narashino, Chiba, Japan L. Thorndahl CERN, Geneva, Switzerland
	The stochastic cooling system of the HESR (High Energy Storage Ring) is based on completely new structures especially designed for the HESR. Each beam surrounding slot of these so called slot-ring couplers covers the whole image current without a reduction of the HESR aperture and without any plunging system. One pickup and one kicker have been already fabricated and installed into the COSY ring to demonstrate stochastic cooling in all three dimensions with only one structure. First results of commissioning with proton beams will be presented. The longitudinal cooling system at HESR is based on filter cooling with an optical notch-filter and ToF cooling. The demanding accuracy concerning phase stability requires dedicated control of the notch-frequency. The optical COSY filter has been modified and can be proven in long term runs together with the new stochastic cooling system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA085
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Stochastic Cooling Hardware for Low Energy Deuterons at COSY

2261

B. Breitkreutz, R. Greven, N. Shurkhno, R. Stassen, H. Stockhorst
FZJ, Jülich, Germany

One of the central utilizations of the COSY facility nowadays is to host experiments for the JEDI (Jülich Electric Dipole moment Investigations) collaboration. These experiments use polarized deuteron beams at momenta below 1 GeV/c, that are stored for several minutes. In order to increase the spin coherence time, beam cooling is necessary. Electron cooling is applied to pre-cool the beam, but the solenoids of the electron cooler may not be perfectly compensated. Thus, stochastic cooling would be desirable instead. Unfortunately, the existing stochastic cooling system is not sensitive at low beam velocities. This paper presents newly developed stochastic cooling pickups and kickers for a system dedicated to low beam velocities of approximately 0.5c. The design is based on the slot-ring type pickups that have been developed for the High Energy Storage Ring (HESR), but optimized for low particle velocities and a low frequency band of 350-700 MHz. Since the structures get much bigger in comparison to the HESR version, mechanical properties must be reconsidered and a trade-off between electrical properties, cooling performance and constructability must be found.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA080

Export •

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

TUPVA085

First Experiences with HESR Stochastic Cooling System

2278

R. Stassen, B. Breitkreutz, T. Katayama, N. Shurkhno, H. Stockhorst
FZJ, Jülich, Germany
T. Katayama
Nihon University, Narashino, Chiba, Japan
L. Thorndahl
CERN, Geneva, Switzerland

The stochastic cooling system of the HESR (High Energy Storage Ring) is based on completely new structures especially designed for the HESR. Each beam surrounding slot of these so called slot-ring couplers covers the whole image current without a reduction of the HESR aperture and without any plunging system. One pickup and one kicker have been already fabricated and installed into the COSY ring to demonstrate stochastic cooling in all three dimensions with only one structure. First results of commissioning with proton beams will be presented. The longitudinal cooling system at HESR is based on filter cooling with an optical notch-filter and ToF cooling. The demanding accuracy concerning phase stability requires dedicated control of the notch-frequency. The optical COSY filter has been modified and can be proven in long term runs together with the new stochastic cooling system.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA085

Export •

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