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.
Response of CsI(Tl) scintillators over a large range in energy and atomic number of ions. Part I: recombination and δ-electrons
Abstract A simple formalism describing the light response of CsI(Tl) to heavy ions, which quantifies the luminescence and the quenching in terms of the competition between radiative transitions following the carrier trapping at the Tl activator sites and the electron–hole recombination, is proposed. The effect of the δ-rays on the scintillation efficiency is for the first time quantitatively included in a fully consistent way. The light output expression depends on four parameters determined by a procedure of global fit to experimental data.
IMF-IMF correlations 3–4-fragment correlations reveal details of the breaking process
Abstract The existence of the Coulomb hole in the IMF-IMF correlation function indicates the breakdown of independent sequential emission of an expanded or nonexpanded source. The Berlin multifragmentation model allows to predict any many-fragment correlation with sufficient statistical accuracy and to trace it back to a few parameters describing the freeze-out configuration: At fixed freeze-out volume the width of the Coulomb hole at low relative velocities is found to be independent of the fragmentation mode. This opens the possibility to determine the size of the freeze-out. For low excitation energies a bump is seen at lower relative velocities in the correlation function. This rise is interpreted as a signal of a very asymmetric hot fission. The reason for the bump is the presence of a very large fragment besides intermediate-mass fragments in multifragmentation events. We analysed the events from different multifragmentation modes. Especially correlation functions for fragmentation events with two very large fragments in addition to an IMF pair may contain information on whether the emission process is simultaneous and statistical, or if not, whether the decay is occurring first by evaporation of smaller particles and then by fission of the rest, or in the opposite way.