Alpha-cluster description of excitation energies inC12(12

Abstract

An alpha-cluster expansion of the Glauber multiple scattering [correction of scatteirng] series is used to calculate the energy transfer spectrum to the 12C projectile in the 12C(12C,3 alpha)X reaction at 2.1A GeV. Cluster-abrasion response functions are defined in terms of alpha-cluster wave function and the collision dynamics appropriate for heavy-ion reactions. Comparisons are made to recent quasiexclusive experimental data with good agreement found. Calculations indicate that substructures in a 12C projectile are likely to be true spectators in fragmentation, however, with virtual states of excitation in the projectile ground state making a significant contribution to the fragmentation cross section.

Description of light ion production cross sections and fluxes on the Mars surface using the QMSFRG model

“…The QMSFRG considers the multiple scattering series for two heavy ions and introduces the impulse and eikonal approximation for the total momentum transfer vector in order to obtain a closed-form solution to the abrasion cross section excitation spectrum [7][8][9][10]. For inclusive reactions where a single fragment originating in the projectile is measured, closure is performed on the final target state with a momentum vector denoted p used to represent these states.…”

“…The total momentum transfer is q X = p T − p X where p T is the initial target momentum. The pre-fragment, F* excitation spectrum following nucleon or alpha particle abrasion was found [7,8] as an impact parameter dependent convolution of the pre-fragment excitation response for a transition of the pre-fragment core from state n to n' and the project fireball response, average over the target ground-state wave function, …”

Transport of light ions in matter

“…These are also interesting ions for which the NUCFRG code (based on a liquid drop model) is expected to be least appropriate (Wilson et al, 1995;Cucinotta and Dubey, 1994b;Cucinotta, 1994a). Hence, the current data set is an important test for the fragmentation database used in space studies.…”

“…It is surmised that the fault lies in the liquid drop assumption. The nuclear interaction viewed as a combination of inelastic, quasielastic, and nonelastic events leads us to assume the main quasielastic event in which specific particles or clusters are removed from a reasonably stable core cannot be accommodated within a liquid drop formalism (Cucinotta and Dubey, 1994b;Cucinotta et al, 1994a) while the highly nonelastic events in which the mass removed from the projectile is fully dissociated is better represented by the NUCFRG2 code. One can see these dynamic differences in the 12C113C ratio in the fragmentation of 40At (ratio of 1) in comparison with the value for fragmentation of 160 (ratio of 2.3) as measured by Tall (1990); Olson et al (1983) respectively.…”

“…The cluster effect for 160 projectiles is taken herein from the work of Cucinotta and Dubey (1994b); Cucinotta et al (1994a) some additional ad hoc adjustments are made to the liquid drop model cross sections representing the non elastic events until a more complete cluster code is available. The resultant database is an improvement over the NUCFRG2 code but Li and Be fragments remain untested by the GSI experiments.…”