HIAT2022 - List of Authors (Bozyk, L.H.J.)

Paper	Title	Page
TUP05	Prototype Room Temperature Quadrupole Chamber with Cryogenic Installations	75
	S. Aumüller, L.H.J. Bozyk, P.J. Spiller GSI, Darmstadt, Germany K. Blaum MPI-K, Heidelberg, Germany
	The synchrotron SIS100 at FAIR accelerator complex at the GSI Helmholtzzentrum will generate heavy ion beams of ultimate intensities. As medium charge states have to be used, the probability for charge exchange in collisions with residual gas particles of such ions is much lager than for higher charge states. In the last years, several measures have lowered the residual gas density to extreme high vacuum conditions. For example 55% of the circumference of SIS18 have already been coated with NEG, which provides high and distributed pumping speed. Nevertheless, this coating does not pump nobel and nobel-like components, which have very high ionization cross sections. A cryogenic environment at e.g. 50-80K provides a high pumping speed for all heavy residual gas particles. The only typical residual gas particle that cannot be pumped at this temperature is hydrogen. With the pumping speed of an additional NEG coating in these areas, the pumping will be optimized for all residual gas particles. The installation of cryogenic installations in the existing room temperature synchrotron SIS18 at GSI has been investigated. Measurements on a prototype chamber and simulations of SIS18 with cryogenic installations based on these measurements are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HIAT2022-TUP05
About •	Received ※ 21 June 2022 — Revised ※ 30 June 2022 — Accepted ※ 01 July 2022 — Issue date ※ 10 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP06	Cryogenic Surfaces in a Room Temperature SIS18 Ioncatcher	79
	L.H.J. Bozyk, S. Aumüller, P.J. Spiller GSI, Darmstadt, Germany
	For FAIR operation, the existing heavy ion synchrotron SIS18 at GSI will be used as booster for the future SIS100. In order to reach the intensity goals, medium charge state heavy ions will be used. Unfortunately, such ions have very high ionization cross sections in collisions with residual gas particles, yielding in beam loss and a subsequent pressure rise via ion impact stimulated gas desorption. To reduce the desorption yield, room temperature ioncatcher have been installed, which provide low desorption surfaces. Simulations including cryogenic surfaces show, that their high sticking probability prevents the vacuum system from pressure built-ups during operation. Such, the operation with heavy ion beams can be stabilized at higher heavy ion intensities, than solely with room temperature surfaces. A prototype ioncatcher containing cryogenic surfaces has been developed and built. The surfaces are cooled by a commercial coldhead, which easily allows this system being integrated into the room temperature synchrotron. The development and first laboratory tests including fast pressure measurements of this system will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HIAT2022-TUP06
About •	Received ※ 21 June 2022 — Accepted ※ 01 July 2022 — Issue date ※ 10 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Prototype Room Temperature Quadrupole Chamber with Cryogenic Installations

75

S. Aumüller, L.H.J. Bozyk, P.J. Spiller
GSI, Darmstadt, Germany
K. Blaum
MPI-K, Heidelberg, Germany

The synchrotron SIS100 at FAIR accelerator complex at the GSI Helmholtzzentrum will generate heavy ion beams of ultimate intensities. As medium charge states have to be used, the probability for charge exchange in collisions with residual gas particles of such ions is much lager than for higher charge states. In the last years, several measures have lowered the residual gas density to extreme high vacuum conditions. For example 55% of the circumference of SIS18 have already been coated with NEG, which provides high and distributed pumping speed. Nevertheless, this coating does not pump nobel and nobel-like components, which have very high ionization cross sections. A cryogenic environment at e.g. 50-80K provides a high pumping speed for all heavy residual gas particles. The only typical residual gas particle that cannot be pumped at this temperature is hydrogen. With the pumping speed of an additional NEG coating in these areas, the pumping will be optimized for all residual gas particles. The installation of cryogenic installations in the existing room temperature synchrotron SIS18 at GSI has been investigated. Measurements on a prototype chamber and simulations of SIS18 with cryogenic installations based on these measurements are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HIAT2022-TUP05

About •

Received ※ 21 June 2022 — Revised ※ 30 June 2022 — Accepted ※ 01 July 2022 — Issue date ※ 10 August 2022

Cite •

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

TUP06

Cryogenic Surfaces in a Room Temperature SIS18 Ioncatcher

79

L.H.J. Bozyk, S. Aumüller, P.J. Spiller
GSI, Darmstadt, Germany

For FAIR operation, the existing heavy ion synchrotron SIS18 at GSI will be used as booster for the future SIS100. In order to reach the intensity goals, medium charge state heavy ions will be used. Unfortunately, such ions have very high ionization cross sections in collisions with residual gas particles, yielding in beam loss and a subsequent pressure rise via ion impact stimulated gas desorption. To reduce the desorption yield, room temperature ioncatcher have been installed, which provide low desorption surfaces. Simulations including cryogenic surfaces show, that their high sticking probability prevents the vacuum system from pressure built-ups during operation. Such, the operation with heavy ion beams can be stabilized at higher heavy ion intensities, than solely with room temperature surfaces. A prototype ioncatcher containing cryogenic surfaces has been developed and built. The surfaces are cooled by a commercial coldhead, which easily allows this system being integrated into the room temperature synchrotron. The development and first laboratory tests including fast pressure measurements of this system will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HIAT2022-TUP06

About •

Received ※ 21 June 2022 — Accepted ※ 01 July 2022 — Issue date ※ 10 August 2022

Cite •

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