Universität zu Köln

Altenkirch, R., Feuerstein, C., Schiffer, M., Hackenberg, G., Heinze, S., Mueller-Gatermann, C. and Dewald, A. (2019). Operating the 120 degrees Dipol-Magnet at the CologneAMS in a gas-filled mode. Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms, 438. S. 184 - 189. AMSTERDAM: ELSEVIER SCIENCE BV. ISSN 1872-9584

Full text not available from this repository.

Abstract

Routine measurements of the last years at the 6 MV AMS system showed a good isobar suppression for all light isotopes, measured with the Degrader-Foil-Method, especially Cl-36 and Be-10. However, the efficiency is reduced due to the charge state distribution generated by the degrader-foil. For measurements injecting atomic Al-26, the ionization efficiency becomes the bottleneck, which leads to a relatively low ion source output. In the case of AlO-, the output is expected about one order of magnitude higher. However, to use AlO- the isobar interference of Mg-26 will become an issue. It has to be suppressed in several steps, e.g. by different dE/dx methods like TOF, degrader-foil or gas-filled magnet. In order to minimize the efficiency losses generated by the degrader-foil method, the 120 degrees-magnet at the 6 MV AMS system was modified to enable a gas-filled operation, and therefore focus the beam to a mean charge state. A constraint for all modification of the detection beam line was that the operation of the degrader-foil method is not affected. In this paper, we report on the performed construction work, as well as test measurements for Al-27 at 40 MeV ion energy. Isobar separation for Cl-36 and S-36 was measured as a function of the gas pressure. We compare measured data with Monte Carlo simulations performed with a computer code developed by our group. In addition, we will present a new dedicated gas ionization chamber designed for particle detection directly after the gas-filled magnet.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Altenkirch, R. UNSPECIFIED UNSPECIFIED UNSPECIFIED Feuerstein, C. UNSPECIFIED UNSPECIFIED UNSPECIFIED Schiffer, M. UNSPECIFIED UNSPECIFIED UNSPECIFIED Hackenberg, G. UNSPECIFIED UNSPECIFIED UNSPECIFIED Heinze, S. UNSPECIFIED UNSPECIFIED UNSPECIFIED Mueller-Gatermann, C. UNSPECIFIED UNSPECIFIED UNSPECIFIED Dewald, A. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-140818
DOI:	10.1016/j.nimb.2018.05.001
Journal or Publication Title:	Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms
Volume:	438
Page Range:	S. 184 - 189
Date:	2019
Publisher:	ELSEVIER SCIENCE BV
Place of Publication:	AMSTERDAM
ISSN:	1872-9584
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language HEAVY; FORMULAS; IONS Multiple languages Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/14081