Two-stage multifragmentation of1AGeV Kr, La, and Au

Abstract

Multifragmentation in fully reconstructed events from 1A GeV Kr and La collisions with C has been studied. Results are compared with similar data for 1A GeV AuϩC. The emitted charged particles and fragments are identified with emission from either a prompt first stage or a second stage in which the remnant resulting from the first stage breaks up. The nuclear charge, mass, and excitation energy distributions of the remnant are determined. The total charged multiplicity, as well as those of the first and second stages are obtained. Freeze-out temperatures and thermal excitation energy permit the determination of the caloric curve. The fragment charge distribution as well as the IMF multiplicity distribution and those of individual fragments are obtained. The various results are examined as to the extent of universal behavior when scaled for varying system size. Comparisons are made with intranuclear cascade and statistical multifragmentation model calculations.

Isospin-dependent multifragmentation of relativistic projectiles

“…The charge distribution evolves from a socalled "U-shaped" distribution, with domination of evaporation of the compound nucleus and asymmetric binary decay during the onset of multifragmentation, to a rapidly dropping exponential distribution. This evolution is a characteristic feature of the present type of spectator fragmentation [23,25,72]. The variation of the symmetry-term coefficient in the calculations, down to one third of its standard value, has a negligible effect on the resulting charge distributions except in the bin of largest jectiles.…”

Determination of the coexistence curve, critical temperature, density, and pressure of bulk nuclear matter from fragment emission data

“…The excited remnant is a thermal source that emits protons, neutrons and other heavier charged fragments. In multifragmentation experiments, the excitation energy is estimated based on measurements of the kinetic energy of the fragments emitted from the remnant and other considerations [40,41].…”

“…Some of the multifragmentation data analyzed here are from the reactions 1 AGeV 197 Au+ 12 C, 1 AGeV 139 La+ 12 C and 1 AGeV 84 Kr+ 12 C and were collected by the EOS Collaboration at the Lawrence Berkeley National Laboratory Bevalac. This experiment studied the projectile fragmentation and detected nearly all of the charged reaction products on an event-by-event basis [4,[40][41][42]. Charged particles with charges of from 1 to 6 were identified using a time projection chamber [43] while a multiple sampling ionization chamber detected charged particles with charges from 7 to 79 [44].…”

Tabulated Equation of State for Supernova Matter Including Full Nuclear Ensemble

“…Randrup and Koonin (1981); Gross (1982); Bondorf et al (1985). These models were able to describe many characteristics of nuclear fragments observed in nuclear experiments: multiplicities of intermediate-mass fragments, charge and isotope distributions, event by event correlations of fragments (including fragments of different sizes), their angular and velocity correlations, and other observables (Gross (1990); Bondorf et al (1995); Souliotis et al (2007); Ogul et al (2011); Botvina, Iljinov, & Mishustin (1990); Botvina et al (1995); Scharenberg et al (2001);D'Agostino et al (1996D'Agostino et al ( , 1999; Bellaize et al (2002); Avdeyev et al (2002); Hauger et al (2000); Iglio et al (2006); Hudan et al (2009); Wang et al (1999); Viola et al (2001); Rodionov et al (2002); Pienkowski et al (2002)). The temperature and density of nuclear matter at the stage of fragment formation can also be established reliably in experiment by measuring relative velocities of fragments and ratios of isotope yields.…”

“…The nuclear composition and thermodynamic properties of nuclear matter under supernova conditions were studied recently within different approaches (Botvina & Mishustin (2010) (Botvina & Mishustin (2004) as a direct generalization of the Statistical Multifragmentation Model -SMM (Bondorf et al (1995)). The SMM was successfully used for description of nuclear multifragmentation reactions (Ogul et al (2011);Botvina et al (1995); Scharenberg et al (2001);D'Agostino et al (1996D'Agostino et al ( , 1999; Bellaize et al (2002); Avdeyev et al (2002); Hauger et al (2000); Iglio et al (2006); Hudan et al (2009);Wang et al (1999); Viola et al (2001)). This gives us confidence that this model can realize a realistic approach to clustered nuclear matter under astrophysical conditions, as discussed in Introduction.…”