The40Ca(t,p)42Careaction at triton energies near 10 MeV per nucleon

Autor: M. A. Nagarajan, P R Hayes, R. P. Ward, C. O. Blyth, Ian J. Thompson, M. Cohler, C.N. Pinder, N.M. Clarke, K I Pearce, A. Ghazarian, D. L. Watson, M. B. Becha
Rok vydání: 1997
Předmět:
Zdroj: Physical Review C. 56:1960-1971
ISSN: 1089-490X
0556-2813
DOI: 10.1103/physrevc.56.1960
Popis: Two nucleon transfer reactions have been used to probe for correlations in nuclei but there have been doubts about the assumptions made and hence about the success of the analyses. An experimental study of the ${}^{40}\mathrm{Ca}{(t,p)}^{42}\mathrm{Ca}$ reaction at incident triton energies of 10\char21{}15 MeV/nucleon was made to determine if the one-step, two-nucleon transfer mechanism was dominant at these energies. Measurements were made with 28, 33, and 37.3 MeV incident energy and particular care was taken to measure absolute differential cross sections for transitions to several residual states in ${}^{42}\mathrm{Ca}.$ The analysis of all the data used the results of full finite-range calculations and care was taken to calculate all the one-step and two-step reaction channels in a consistent manner starting from a shell-model description of the relevant Ca isotopes with a single, large basis set of single-particle wave functions. Although a complete prediction of the data was not achieved, it is concluded that incident triton energies about 10 MeV/nucleon are still not enough for one-step, two-nucleon transfer to dominate the $(t,p)$ reaction mechanism. Even with a full analysis, it was not possible to reliably extract the reaction amplitudes by fitting the data because of the effects of the discrete potential ambiguity when describing elastic scattering. Hence it is not possible to extract accurate data about two-nucleon correlations in nuclei from $(t,p)$ reactions at these energies. Additionally, some measurements on the ${}^{8}\mathrm{Ca}{(t,p)}^{50}\mathrm{Ca}$ reaction with 37.3 MeV incident energy are presented. Using a similar analysis, calculations predicted the magnitude of the differential cross-section data and the structure of the angular distributions. The ${J}^{\ensuremath{\pi}}$ of the second excited state of ${}^{49}\mathrm{Ca}$ was shown to be ${7/2}^{\ensuremath{-}}.$
Databáze: OpenAIRE
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