Gießen 2007 – scientific programme

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HK: Fachverband Physik der Hadronen und Kerne

HK 49: Poster

HK 49.42: Poster

Thursday, March 15, 2007, 16:00–17:00, P

Preparation of isotopically enriched mercury sulphide targets — •J. Szerypo, H. U. Friebel, D. Frischke, R. Grossmann, and H. J. Maier — Department für Physik, Universität München (LMU) and Maier-Leibnitz-Laboratorium (MLL), D-85748 Garching, Germany

The primary difficulty in performing nuclear reactions on mercury is to obtain a suitable target. The primary difficulty in performing nuclear reactions on mercury is to obtain a suitable target. The utilization of amalgam targets has been reported in early publications [1,2]. These targets, however, were lacking homogeneity and in-beam stability. A thorough investigation of literature shows, that HgS, because of its comparatively high chemical and mechanical stability, is one of the more adequate Hg compounds for accelerator target applications. In this presentation we describe the production of HgS targets consisting of an enriched Hg isotope and S of natural isotopic abundance, starting up from HgO. Following the outline given in [3], in this special case HgS can be prepared by dissolving HgO in diluted HNO₃ and subsequent precipitation of the black HgS modification with gaseaous H₂S. Last step of the target production procedure is evaporation-condensation of HgS in vacuum. In the present case, HgS layers of 500 µg/cm² on a backing carbon foil of 26 µg/cm² with a protective carbon layer of about 20 µg/cm² thickness on top of the HgS layer were produced.

[1] H. Bohn et al., MLL Annual Report 1973, p. 53 [2] H. Puchta, Diploma Thesis, Sektion Physik, LMU Muenchen, 1974 [3] H.U. Friebel et al., Proc. Fifth Annual Conference of the INTDS, Oct. 19-21, 1976, Los Alamos, New Mexico, (LA 6850-C)