L.B. Hughes

A study of the 55Mn(n, γ)56Mn reaction

Abstract The gamma radiation from the 55 Mn(n, γ) 56 Mn reaction has been studied using a Ge(Li) spectrometer and also a Ge(Li)-NaI coincidence spectrometer. A total of 130 gamma rays were observed and their intensity and energy determined. The neutron separation energy was found to be 7272±3 keV . The level structure for the first 4000 keV is in excellent agreement with the (d, p) results. The decay modes of several of the low-energy states have been deduced from coincidence and energy information. A calculation of the correlation between the gamma-ray reduced widths and the (d, p) strength yields a coefficient of +0.84.

Large volume lithium-drifted germanium gamma-ray detectors☆

Abstract A new electroplating method was used for the fabrication of large-volume Ge(Li)-detectors in “wrap-around” configuration. The properties and performance of a 6 cm3 and a 10 cm3 detector were investigated. Some applications are described.

A study of the 127I(n, γ)128I and 133Cs(n, γ)134Cs reactions

Abstract The capture γ-ray spectra of the 127 I(n, γ) 128 I and 133 Cs(n, γ) 134 Cs reactions have been investigated using a Ge(Li) spectrometer. A total of 184 high- and low-energy γ-rays were observed for the 127 I(n, γ) 128 I reaction. A neutron separation energy of 6826±3 keV was deduced by means of coincidence experiments. For the 133 Cs(n, γ) 134 Cs reaction 86 γ-rays were observed. Both spectra show an enhancement of high energy intensity which appears to be related to a high level density at low excitation energy.

A study of the 59Co(n, γ)60Co reaction

The gamma radiation from the 56Co(n, γ)60Co reaction has been studied using a Ge(Li) spectrometer. A total of 122 transitions was observed and their intensity and energy determined. The neutron separation energy of 7495±5 keV was obtained. The level structure of 60Co was determined from the primary transitions and compared to those revealed in charged particle spectra. A decay scheme has been constructed for some of the lower-lying levels. An observed dependence of partial radiative widths on the final state structure is discussed.

The level structure of 140La and 142Pr from the (n, γ) reaction

Abstract A study of the 139 La(n, γ ) 140 La and 141 Pr(n, γ ) 142 Pr reactions using a Ge(Li) spectrometer has given neutron separation energies of 5165±5 and 5842±5 keV, respectively. Both nuclei have reasonably simple spectra for doubly-odd species due to the 83 neutron configuration. About 40 high-energy transitions were found in each case, and for 140 La the reduced dipole width to f-wave neutron states appears wider than to p-wave states. The low-energy transitions for both nuclei were also examined.

Study of thermal neutron capture in sulphur

Abstract The 32 S(n, γ) 33 S reaction has been studied using a Ge(Li) and a Ge(Li)NaI(TI) spectrometer. The principal aim was to establish a set of accurate energies for high-energy gamma-ray standards. In order to employ energy loops for consistency checks, a coincidence experiment was also conducted. The neutron separation energy was determined to be 8646 ± 1 keV for 33 S and 6988 ± 2 keV for 35 S and the energies of virtually all the transitions observed are accurate to 2 keV. The two parameter coincidence experiment revealed the presence of a strong 4640-2348 keV cascade belonging to the 34 S(n, γ) 35 S reaction.

The 39K(n, γ)40K reaction

Abstract The gamma radiation from the 39K(n, γ)40K reaction has been studied using a Ge(Li) spectrometer. A total of 65 transitions was observed with an average precision of 3 keV. The neutron separation energy was found to be 7797±3 keV. A detailed comparison with (d, p) results reveals that the M1 and E1 strengths are almost equal as are the transitions to ln = 1 and ln = 3 levels. The results presented indicate that this reaction proceeds mainly through compound nucleus formation.