Light particle emission inO16-induced reactions at 140, 215, and 310 MeV

Abstract

Double differential cross sections have been measured for energetic p, d, t, and u particles emitted in 0-induced reactions on targets of Al, Zr, and Au at incident energies of 140, 215, and 310 MeV. The energy and angular distributions are well described by isotropic emission from a moving thermal source. The extracted temperature and velocity parameters are found to vary systematically with the incident energy per nucleon above the Coulomb barrier. The observed trends cannot be explained by compound nucleus emission but instead suggest emission from a source which consists of comparable contributions from target and projectile. Alternatively, the proton energy spectra are compared with a precompound model and with a simple knockout model. The d, t, and a-particle cross sections are also described in terms of a generalized coalescence relation which takes into account Coulomb repulsion from the target nucleus. NUCLEAR REACTIONSAl(' O~), E=140, 215, and 310 MeV; Zr(' O~), E =215 and 310 MeV; ' Au('6O~), E =140, 215, and 310 MeV; x =p, d, t, and a. Measured o. (E",O"}. Analysis in terms of moving source, precompound, knockout, and coalescence models.

Nuclear stopping and light charged particle emission in C12+C12 at 95 MeV/nucleon

“…7 indicate that this difference originates from the exhibition of the alpha cluster structure in 12 C nuclei when they are excited below 10-15MeV [44,45]. In our analysis, the P 0 values for 4 He and deuterons show a similar value for the IV component, which is distinct contract to those of other analysis, such as those of 40 Ar + 112 Sn at 47 MeV/nucleon [46] and 16 O + 197 Au at 310 MeV/nucleon [7]. In these references, deuterons show smaller P 0 values, reflecting the weak binding and therefore a possible large spread of nucleons in the deuterons.…”

“…As shown in the figures, IMFs originate from two sources, PLF at the forward angles and TLF at larger angles. For 7 Li the spectra are dominated by the secondary emission, though the magnitude is more than 10 times smaller in the calculation. The contribution from the primary process increases as the mass increases and for 11 C, the primary products becomes comparable.…”

“…As mentioned in the introduction, the energy spectra in intermediate energy heavy ion collisions can be described well by a moving source fit with three sources, that is, PLF, IV and TLF sources [6][7][8][9]. For the later discussions, we first perform a moving source characterization of LCP spectra to characterize the experimental energy spectra at different …”

“…Wada et al, applied an antisymmetrized molecular dynamics (AMD) for 64 Zn + 58 Ni, 92 Mo, 197 Au at 26 to 47 MeV/nucleon and showed that AMD reproduces reasonably well the multiplicity and energy distributions of LCPs, including those of the intermediate mass fragments [20]. For light cluster emissions at intermediate energy domains, it has been shown that their energy spectra are well described by a thermal coalescence model [6,7,21]. A possible difference of the emission mechanisms for the IV source component of the protons and alpha clusters is suggested using a kinematical three body calculation in 32 S + Ag at 30 MeV/nucleon in Ref [22].…”

“…Particle spectra at intermediate energy collisions have been empirically analyzed, using a moving source fit with three sources, projectile-like (PLF), intermediate velocity (IV) and target-like (TLF) sources [6][7][8][9]. The IV source has a source velocity of about a half projectile velocity and a harder slope, comparing to those of PLF and TLF.…”