Multifragmentation threshold in 93 Nb + nat Mg collisions at 30 MeV/nucleon
We analyzed the $^{93}Nb$ on $^{nat}Mg$ reaction at $30$ MeV/nucleon in the aim of disentangling binary sequential decay and multifragmentation decay close to the energy threshold, i.e. $\simeq 3$ MeV/nucleon. Using the backtracing technique applied to the statistical models GEMINI and SMM we reconstruct simulated charge, mass and excitation energy distributions and compare them to the experimental ones. We show that data are better described by SMM than by GEMINI in agreement with the fact that multifragmentation is responsible for fragment production at excitation energies around $3$ MeV/nucleon.
Excitation energy and angular momentum of quasiprojectiles produced in the Xe+Sn collisions at incident energies between 25 and 50 MeV/nucleon☆
Abstract The excitation energy and angular momentum transferred to quasiprojectiles have been measured in the 129 Xe+ nat Sn collisions at bombarding energies between 25 and 50 MeV/nucleon. The excitation energy of quasiprojectiles has been determined from the kinetic energy of all decay products (calorimetry). It increases with the violence of the collision, approaching 10 MeV/nucleon in the most dissipative ones. The angular momentum has been deduced from the kinetic energies and angular distributions of the emitted light charged particles (p, d, t, 3 He and α ). The (apparent) spin value decreases with the violence of the collision. Larger spin values are observed at the lowest bombarding energy. Data are compared with the predictions of dynamical and statistical models. They reproduce the data in a quantitative way indicating that large spin values are transferred to quasiprojectiles during the interaction. The results show that the one-body dissipation formalism still applies at intermediate bombarding energies and low-energy dissipations. With the increase of the energy, the data seem to be better described when the two-body interaction is accounted for.
Line Arrester Energy Discharge Duties
Surge arresters could practically eliminate lightning flashovers on distribution lines, if they are properly deployed in large enough numbers, and if they could survive the current and energy discharge duties imposed by high-magnitude lightning strokes. The discharge duty depends on complex interactions between the arrester locations, grounding, shielding from nearby objects, and the local lightning environment. But many factors of traditional concern with distribution arrester application, such as the lead length, surge front time, and protective margin, play little or no role in the discharge duty. Probabilistic methods determine the expected arrester failure rate. This should be much lower than the original flashover rate on the line insulation, otherwise the design is not acceptable. A transient program such as EMTP/ATP provides the best tool for calculating the discharge duty, but simplified methods are also available