| Multifragmentation processes have been studied by measuring 129 Xe+197Au collisions at 50A MeV with a large area silicon-strip/CsI detector array (LASSA). The LASSA was designed and constructed to provide excellent energy, angular and isotope resolution for the detection of charged particles. Each of nine LASSA telescopes consists of two silicon strip detectors (65mum and 500mum thick, respectively) and four CsI(Tl) crystals. A non-uniformity in light output of the CsI(Tl) crystals better than 1% was obtained via the crystal selection and quality control procedure. Isotopically resolved particles from hydrogen to oxygen were detected in polar angles of 12° < theta < 62° with an angular resolution of +/-0.43°.;Experimental correlation functions for particles detected in LASSA are analyzed using the Koonin-Pratt formalism and by making an assumption of thermal equilibrium. A method of probing the breakup density is demonstrated and the results from the equilibrium approach are compared with those from the Koonin-Pratt formalism for light particle correlations. The extracted values of the free volume are about 2.5 (10% uncertainty) times the volume of the total system at saturation density, which corresponds to a freezeout density of 1/5--1/3 times the nuclear saturation density.;A new technique of spin determination from particle correlation functions is proposed utilizing the same equilibrium assumption. A few examples of correlation functions are studied to demonstrate the promising sensitivity of this new technique. In particular, the spin of the first excited state of 8 B at 0.774 MeV is determined as J = 1 via the p-7Be correlation function.;To better understand the isospin effects and to further confront calculations with experimental data, an empirically modified statistical multifragmentation model (SMM) was developed.;From the isotopic composition of particles emitted during an energetic nucleus-nucleus collision, we can test the isospin dependence of the nuclear equation of state (EOS). Hybrid calculations were performed using isospin dependent BUU transport model and the improved SMM. Comparisons between measured isotopic yield ratios and theoretical predictions in the equilibrium limit are used to assess the sensitivity to the density dependence of the asymmetry term of the EOS. This analysis suggests preference for a stiff density dependence and indicates that such comparisons may provide an opportunity to constrain this important property of nuclear matter. (Abstract shortened by UMI.). |
