| Abstrakt: |
Excitation functions for the reactions 197Au(p,n)197gHg and 197Au(p,n)197mHg have been measured over the energy ranges from threshold up to 20 MeV using stacked foil activation technique. The isomeric cross-section ratio σm/(σm+σg) for the formation of 197g, mHg was determined. The excitation functions and isomeric cross-section ratios were calculated for the reactions 197Au(p,n)197g,mHg, 197 Au(p,2n)196Hg, 197Au(p,3n)195g,mHg, 197Au(p,4n)194Hg, 197 Au(p,5n)193g,mHg, 197Au(α, n)200Tl, 197Au(α,2n)199Tl, 197Au(α,3n)198g,mTl, 197Au(α,4n)197Tl and 197Au(α,5n)196g,mTl from reaction threshold up to 40 MeV for proton induced reactions and 80 MeV for alpha induced reactions. The results were compared with the theoretical cross-sections calculated by means of the code EMPIRE-II and with the available literature data, which makes use of the Hauser Feshbach model for the compound nuclear calculations and the exciton model for the pre-equilibrium emission part. The isomeric cross-section ratio is found to depend strongly on the relative spins of the isomeric and ground state, energy difference between the levels, presence of intermediate states and some dependence on decay modes and on the onset of pre-equilibrium emission. [ABSTRACT FROM AUTHOR] |
