DETERMINATION OF THE SI-29 LEVEL DENSITY FROM 3 TO 22 MEV

The level density of Si-29 has been studied over an excitation energy range of 3 to 22 MeV. Three techniques were used to derive level densi ty values from experimental data. In the region of resolved levels, re sults were obtained from level counting while neutron resonance data w ere used in the region of slightly overlapping levels near the neutron binding energy. At the highest excitation energies, characterized by strongly overlapping levels, Ericson theory was employed to deduce lev el densities by examining energy-dependent fluctuations in cross secti ons. Three reactions yielding the same compound nucleus, Si-29, were i nvestigated. Partial cross sections from Si-28(n,p), Si-28(n,alpha), a nd Al-27(d,n) Si-28 reactions were measured with good experimental res olution and statistical accuracy. From these cross sections, level den sities were extracted using the two independent methods proposed by Er icson. Reasonable agreement was found among level densities derived fr om the two Ericson methods. Values obtained are also fairly consistent with those of various predictions and theoretical models.