Theoretical Evaluation of the Reaction Rates for 26Al(n,p)26Mg and 26Al(n,a)23Na

The reactions that destroy 26Al in massive stars have significance in a number of astrophysical contexts. We evaluate the reaction rates of 26Al(n,p)26Mg and 26Al(n,a)23Na using cross sections obtained from the codes EMPIRE and TALYS. These have been compared to the published rates obtained from the non-smoker code and to some experimental data. We show that the results obtained from EMPIRE and TALYS are comparable to those from non-smoker. We also show how the theoretical results vary with respect to changes in the input parameters. Finally, we present recommended rates for these reactions using the available experimental data and our new theoretical results

Gamma-gamma angular-correlation measurements in the 44Ca(n, γ)45Ca reaction

Angular correlation measurements of γ-radiation following thermal neutron capture in 44Ca have been performed with a combination of Ge(Li) and NaI detectors. Spins could be assigned to the following 45Ca levels (Ex in MeV): Jπ(0.17) = , , and assignment is consistent with recent shell-model calculations. Some E2/M1 mixing ratios of transitions between bound states of 45Ca have been determined

Thermal-neutron capture gamma rays from natural calcium

Gamma rays from thermal-neutron capture in natural Ca and enriched 40Ca were investigated with a 5 cm3 Ge(Li) detector. Many low-energy γ-lines have been found. More than 90% of the γ-rays result from capture in 40Ca and about 5% from capture in 44Ca. From the data a decay scheme of 41Ca and a partial decay scheme of 45Ca were constructed. The Q-values for the reactions 40Ca(n, γ)41Ca and 44Ca(n, γ)45Ca were determined as Q = 8363.4±1.0 and 7418.1±3.0 keV,respectively. In 41Ca, it is found that hole states preferentially decay to hole states, and single-particle states to single-particle states

Investigation of the 32S(n, γ)33S reaction

The γ radition following thermal neutron capture in 32S was investigated with scintillation spectrometers. From γ-γ coincidence and angular correlation measurements the following spin assignments in 33S were derived: New transitions in the γ-ray decay were found, a few of which are of M1 character competing favourably with E1 radiation

Thermal-neutron capture gamma rays from natural magnesium and enriched 25Mg

Gamma rays from neutron capture in natural magnesium and in enriched 25Mg have been studied with Ge(Li) detectors. Altogether 101 γ-rays have been observed. Most of these γ-rays could be fitted into the level schemes of 25Mg, 26Mg and 27Mg. If it is assumed that the capture cross section for natural magnesium amounts to 64±3 mb, the capture cross sections for 24Mg, 25Mg and 26Mg have been determined as 52±13 mb, 182±50 mb and 34±10 mb, respectively

Investigation of the 42Ca(n, γ)43Ca reaction

Gamma rays from thermal-neutron capture in enriched 42Ca were investigated with Ge(Li) detectors. Gamma-gamma coincidence measurements were performed with a Ge(Li)---NaI detector combination. A decay scheme of 43Ca has been constructed containing 42 of the 47 observed γ-lines. The excitation energies of 16 levels of 43Ca were determined with uncertainties of 0.2 to 1.1 keV. The 42Ca(n,γ) reaction Q-value is Q = 7932.7±0.5 keV. From the γ-decay, can be assigned to the ln(d, p) = 1 level at Ex = 2046 keV. A strong correlation between the (n, γ) and (d, p) strengths was found

User manual for THRES-F Code

5.00Available from British Library Document Supply Centre- DSC:9091.9F(CLM-R--261) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Intercomparison of adjusted data sets for capture cross sections of fission products

SIGLEAvailable from CEN Saclay, Service de Documentation, 91191 Gif-sur-Yvette Cedex (France) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc