Correlations between the nuclear level density parameters

A recent set of nuclear level density parameters obtained for the constant temperature (CT) and back-shifted Fermi gas (BSFG) model is reviewed. Very simple correlations are observed between the parameters T of CT, and a of BSFG, and between $E_0$ of CT and $E_1$ of BSFG. The average behavior of the level density parameter a with mass number is found to be $a~A^{0.90}$.

Figure 1

(Color online) Examples of fits of the experimental cumulative number of levels of different nuclei from our set with the BSFG and CT model formulas. Note that the fit was also made to the level spacing at the neutron resonance energy, which is not shown on the graphs.

Figure 2

(Color online) Empirical relations between the parameters T (of CT) and a (of BSFG) and between the back shifts $E_0$ (of CT) and $E_1$ (of BSFG).