Isoscaling of fragments with Z = 1 − 17 from reconstructed quasiprojectiles

• Published in: Physical review. C, Nuclear physics Nuclear physics, 2009-06, Vol.79 (6), Article 061602
• Main Authors: Wuenschel, S., Dienhoffer, R., Souliotis, G. A., Galanopoulos, S., Kohley, Z., Hagel, K., Shetty, D. V., Huseman, K., May, L. W., Soisson, S. N., Stein, B. C., Caraley, A. L., Yennello, S. J.
• Format: Article
• Language: English
• Subjects: EVOLUTION; EXCITATION; HEAVY ION REACTIONS; KRYPTON 78; KRYPTON 86; MEV RANGE 10-100; NEUTRONS; NICKEL 58; NICKEL 64; NIMROD; NUCLEAR PHYSICS AND RADIATION PHYSICS; PROTONS; SYMMETRY
• ISSN: 0556-2813; 1089-490X
• DOI: 10.1103/PhysRevC.79.061602

In heavy-ion collisions, isoscaling provides a method for studying the evolution of nuclear symmetry energy as a function of excitation energy. One challenge in using isoscaling is to accurately determine the neutron-to-proton ratio (N/Z) of the fragmenting source. Isoscaling results are presented for the reactions of {sup 86,78}Kr+{sup 64,58}Ni at 35 MeV/nucleon taken on the NIMROD-ISiS array at Texas A and M University. The N/Z of the source was calculated from the isotopically identified fragments and experimentally measured neutrons emitted from reconstructed quasiprojectiles. These data exhibit isoscaling for elements with Z=1-17 over a broad range of isotopes. The isoscaling parameter {alpha} is shown to increase with increasing difference in the neutron composition ({delta}) of the compared sources. For a selected {delta}, the ratio {alpha}/{delta} is also shown to decrease with increasing excitation energy. This may reflect a corresponding decrease in the nuclear symmetry energy.