München 2006 – wissenschaftliches Programm
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HK: Physik der Hadronen und Kerne
HK 21: Postersitzung
HK 21.81: Poster
Dienstag, 21. März 2006, 15:30–17:00, P
Development of Neutron-Time-Of-Flight Detectors for the Investigation of Astrophysically Relevant (γ,n)-Reactions — •R. Beyer1, E. Grosse1,2, K. Heidel1, J. Hutsch1, A.R. Junghans1, J. Klug1, G. Rusev1, K.D. Schilling1, R. Schwengner1, and A. Wagner1 — 1Institut für Kern- und Hadronenphysik, FZ Rossendorf, PF 510119, 01314 Dresden, Germany — 2Institut für Kern- und Teilchenphysik, TU Dresden, 01062 Dresden, Germany
For future experiments at the new bremsstrahlung facility [1] at the ELBE accelerator of the FZ Rossendorf, several types of neutron scintillation detectors (Li-glass-, ZnS- and plastic) were investigated. They will be applied to detect neutrons produced in (γ,n) reactions in nuclei, which are relevant to the astrophysical nucleosynthesis in the energy range from 20 keV - 2 MeV.
A VME-based data-acquisition system was set up with TDCs (CAEN V1190A) and QDCs (CAEN V792). List-mode data with correlated time and energy informations of up to 10 detectors were recorded simultaneously using a real-time operating system. A 252Cf neutron source was used to measure the time resolution and to estimate the neutron-detection efficiency.
The plastic scintillators can reach efficiencies > 50 % at En=50 keV using a coincidence trigger threshold just below the single electron peak of the photomultiplier tubes [2]. A time resolution of about 1 ns (FWHM) has been achieved.
[1] R. Schwengner et al., NIM A 555 (2005) 211
[2] N.W. Hill et al., IEEE Transactions on Nucl. Sci., Vol. NS-32, 1985