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HK: Hadronen und Kerne

HK 56: Polarisierte Ionenstrahlen und Targets II

HK 56.6: Vortrag

Mittwoch, 26. März 1997, 18:45–19:00, HS K

The Liquid Hydrogen/Deuterium Target at the external COSY Experiments — •A. Hassan* for the COSY-TOF Collaboration. * on leave from AEA, NRC Egypt —
Institute f"ur Kernphysik, Forschungszentrum J"ulich,
D-52425 J"ulich.

For the COSY-TOF experiments it is essential that all forms of background are kept to a minimum. A large source of background is the condensation of nitrogen, oxygen, water etc. due to kryogenic effects on the target foils. A fast method of cleaning the foils by heating up the target cell to 280 K with a SMD resistor (6 Watt ) is introduced. This procedure takes only 10 minutes. The target cell is built from a 45  µm thick copper tube and has window foils of only 0.9 µm. Measurements of the evaporation of the condensed gases on the target tube as a function of time will be shown. The effect on the quality of the measured data is demonstrated.
Another improvement is the construction of a 2 mm thick target which will further reduce the energy uncertainty and double scattering background.

[1] V. Jaeckle.et al, Nucl. Inst. and Meth. Phys. 347, 3316 (1981)