1. The Argonne Fragment Mass Analyzer and measurements of entry distributions.
- Author
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Heinz, A., Khoo, T. L., Reiter, P., Ahmad, I., Bhattacharyya, P., Caggiano, J., Carpenter, M. P., Cizewski, J. A., Davids, C. N., Henning, W. F., Janssens, R. V. F., Jones, G. D., Julin, R., Kondev, F. G., Lauritsen, T., Lister, C. J., Seweryniak, D., Siem, S., Sonzogni, A. A., and Uusitalo, J.
- Subjects
GERMANIUM diodes ,GAMMASPHERE - Abstract
The Argonne Fragment Mass Analyzer (FMA) is designed to separate and identify evaporation residues according to their mass-to-charge ratio. The FMA in combination with GAMMASPHERE — an array of 100 compton-suppressed germanium detectors — allowed for a number of very interesting in-beam gamma-spectroscopy studies, as the FMA provided a very clean trigger on evaporation residues to obtain extremely background-free gamma-spectra. This setup was used to measure the total gamma-energy and multiplicity after particle evaporation — the so-called entry distribution — by exploiting the calorimetric properties of GAMMASPHERE, using its germanium detectors as well as its BGO shields for a maximum gamma efficiency. The entry distribution can be used to estimate the height of the fission barrier as a function of angular momentum. This method is especially favorable for unstable nuclei, for which the fission barrier is otherwise very difficult to measure. Here, the entry distributions of [sup 220]Th at beam energies of 206 MeV and 219.5 MeV in the [sup 176]Yb([sup 48]Ca,4n) reaction are presented. The results are compared to a previous measurement. [ABSTRACT FROM AUTHOR]
- Published
- 2001