Properties of projectile-fragments in the 40Ar+27Al reaction at 44 A MeV. Comparison with a multisequential decay model

Abstract

Results on projectile fragment-fragment coincidences in the forward direction and for the reaction 40 Ar+ 27 Al at 44 A.MeV are presented and compared with the predictions of two different entrance channel models, a two-body and a three-body mechanism both followed by a binary multisequential decay including fission. This analysis shows that many features of the projectile decay products are well accounted for by the binary multisequential decay model. However the results depend critically upon the initial masses and excitation energies of the primary projectile fragments. In this respect, the three-body approach underestimates the excitation energy imparted to the primary fragments whereas the two-body scenario overestimates it. The present data put strong constraints on the initial excitation energy imparted to the primary fragments which appears to be intermediate between the predictions of the two models.

Projectile fragmentation reactions of40Ar at 57 MeV/nucleon

“…When more nucleons are removed, effects such as nucleon transfer and evaporation tend to lead the isospin close to the β stability line. The interesting thing is that, for the light fragments, the N f /Z f ratio goes toward the projectile again, which is different from some early works [43][44][45][46]. Although the N/Z values of 9 Be and 181 Ta are much different (1.25 for 9 Be and 1.479 for 181 Ta), no obvious difference has been observed for the N f /Z f ratio.…”

On-Beam Digital Pulse Shape Acquisition From NE102A-${\rm BaF}_{2}$ Phoswich Detector

“…An enhancement in the application of to medium energy physics arrived with the possibility to detect at the same time light charged particle (isotopically separated) and heavy ions (charge separation only), by just putting at the surface of the crystal a typical fast plastic scintillator (NE102A) [11], [12] exploiting the advantages of the phoswich technique [13], [14] and of the high time resolution [1]. The Argos forward wall, constituted by about 60 of such phoswiches, has already been successfully used for studying nuclear reaction mechanisms in experiments at intermediate energies [15], [16]. It has been also adapted for the measurement of fast electrons [17].…”