Gamma-widths, lifetimes and fluctuations in the nuclear quasi-continuum

Statistical $\gamma$-decay from highly excited states is determined by the nuclear level density (NLD) and the $\gamma$-ray strength function ($\gamma$SF). These average quantities have been measured for several nuclei using the Oslo method. For the first time, we exploit the NLD and $\gamma$SF to evaluate the $\gamma$-width in the energy region below the neutron binding energy, often called the quasi-continuum region. The lifetimes of states in the quasi-continuum are important benchmarks for a theoretical description of nuclear structure and dynamics at high temperature. The lifetimes may also have impact on reaction rates for the rapid neutron-capture process, now demonstrated to take place in neutron star mergers.Comment: CGS16, Shanghai 2017, Proceedings, 5 pages, 3 figure

Scissors resonance in the quasi-continuum of Th, Pa and U isotopes

The gamma-ray strength function in the quasi-continuum has been measured for 231-233Th, 232,233Pa and 237-239U using the Oslo method. All eight nuclei show a pronounced increase in gamma strength at omega_SR approx 2.4 MeV, which is interpreted as the low-energy M1 scissors resonance (SR). The total strength is found to be B_SR = 9-11 mu_N^2 when integrated over the 1 - 4 MeV gamma-energy region. The SR displays a double-hump structure that is theoretically not understood. Our results are compared with data from (gamma, gamma') experiments and theoretical sum-rule estimates for a nuclear rigid-body moment of inertia.Comment: 11 pages, 9 figure

A Medical Support in Offshore Racing — Workshop on Medical Support for Offshore Yacht Races, Telemedical Advice Service (TMAS), 1–2 December 2018, London, United Kingdom

The safety and health of sailors offshore is of major concern. World Sailing (WS) and International Maritime Health Association (IMHA) are taking seriously the potential dangers to the safety and health at sea. By the nature of their sport, the sailors racing in offshore racing environment can be exposed to injuries and other health problems that can endanger their lives. Being aware of the potential dangers caused by the distance from onshore health facilities and lack of professional help on board, IMHA and WS decided to support the activities that are leading to the enhancement of safety and health protection on board. With common initiative, joint Workgroup on Medical Support in Offshore Racing has been formed and the series of workshop organised. The WS/IMHA Workgroup on Medical Support for Offshore Yacht Races previously reached consensus on the common competences and learning outcomes for medical training for offshore racing. In addition, the Workgroup has also set standards for required medical kit inventory for yachts par- ticipating in the various categories of offshore yacht races. Documents were both approved by WS Medical Commission and the IMHA Board. Fourth workshop on Medical Support for Offshore Yacht Races was held in London, United Kingdom, 1–2 December 2018 and workgroup reached consensus on the standards for availability of Telemedical Advice Services (TMAS) for the various categories of offshore yacht races held under the authority of WS. This position paper sets out how the TMAS should be integrated with the practical usage of medicines and medical equipment on board offshore racing yachts. In addition, this position paper also sets out how the level of medical training integrates with appropriate use of the TMAS. Overall, the three WS/IMHA position papers on the triad of medical inventories, medical training and TMAS, are aimed at providing the best possible medical care on offshore racing yachts, by fully integrating each part of the triad of medical support.

Spectroscopic studies of Dy-168,170 using CLARA and PRISMA

Preliminary results from an experiment aiming at Dy-170. Submitted to the LNL Annual Report 2008.Comment: 2 pages, 4 figures, Submitted to the LNL Annual Report 200

Statistical properties of 243^{243}Pu, and 242^{242}Pu(n,γ\gamma) cross section calculation

The level density and gamma-ray strength function (gammaSF) of 243Pu have been measured in the quasi-continuum using the Oslo method. Excited states in 243Pu were populated using the 242Pu(d,p) reaction. The level density closely follows the constant-temperature level density formula for excitation energies above the pairing gap. The gammaSF displays a double-humped resonance at low energy as also seen in previous investigations of actinide isotopes. The structure is interpreted as the scissors resonance and has a centroid of omega_{SR}=2.42(5)MeV and a total strength of B_{SR}=10.1(15)mu_N^2, which is in excellent agreement with sum-rule estimates. The measured level density and gammaSF were used to calculate the 242Pu(n,gamma) cross section in a neutron energy range for which there were previously no measured data.Comment: 9 pages, 8 figure

Completing the nuclear reaction puzzle of the nucleosynthesis of 92Mo

One of the greatest questions for modern physics to address is how elements heavier than iron are created in extreme, astrophysical environments. A particularly challenging part of that question is the creation of the so-called p-nuclei, which are believed to be mainly produced in some types of supernovae. The lack of needed nuclear data presents an obstacle in nailing down the precise site and astrophysical conditions. In this work, we present for the first time measurements on the nuclear level density and average strength function of $^{92}$Mo. State-of-the-art p-process calculations systematically underestimate the observed solar abundance of this isotope. Our data provide stringent constraints on the $^{91}$Nb$(p,{\gamma})^{92}$Mo reaction rate, which is the last unmeasured reaction in the nucleosynthesis puzzle of $^{92}$Mo. Based on our results, we conclude that the $^{92}$Mo abundance anomaly is not due to the nuclear physics input to astrophysical model calculations.Comment: Submitted to PR