BARC/PUB/2013/0871

 
 

Nuclear temperatures from evaporation fragment spectra and observed anomalies

 
     
 
Author(s)

Ray, A.; De, A.; Chatterjee, A.; Kailas, S.; Banerjee, S. R.; Banerjee, K.; Saha, S.
(NPD)

Source

Physical Review-C, 2013. Vol. 87 (6): pp. 064604.1-064604.15

ABSTRACT

The extreme back-angle evaporation spectra of alpha, lithium, beryllium, boron and carbon from different compound nuclei near A ≈ 100 (EX = 76–210 MeV) have been compared with the predictions of standard statistical model codes such as CASCADE and GEMINI. It was found that the shapes of the alpha spectra agree well with the predictions of the statistical models. However, the spectra of lithium, beryllium, boron, and carbon show significantly gentler slopes implying higher temperature of the residual nuclei, even though the spectra satisfy all other empirical criteria of statistical emissions. The observed slope anomaly was found to be largest for lithium and decreases at higher excitation energy. These results could not be understood by adjusting the parameters of the statistical models or from reaction dynamics and might require examining the statistical model from a quantum mechanical perspective.

 
 
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