Fragment emission mechanism in the ${}^{32}\mathrm{S}+{}^{12}\mathrm{C}$ reaction

The complex fragment emission from the decay of fully energy-relaxed composite, ${}^{44}\mathrm{Ti}^{*}$ formed via the ${}^{32}\mathrm{S}+{}^{12}\mathrm{C}$ reaction at two excitation energies, have been studied. Inclusive energy distributions of the fragments ($3\le Z\le 8$) emitted in the reaction ${}^{32}\mathrm{S}+{}^{12}\mathrm{C}$ have been measured in the angular range $\sim {16}^{\circ }–{28}^{\circ }$, at two incident energies, 200 and 220 MeV, respectively. Damped fragment yields in all the cases have been found to have the characteristic of emission from fully-energy-equilibrated composites. The binary fragment yields are found to be in good agreement with the standard statistical model predictions of the extended Hauser–Feshbach model (EHFM).

Figure 1

Typical two-dimensional spectrum of fragments obtained in the reaction ${}^{32}\mathbf{S}+{}^{12}\mathbf{C}$.

Figure 2

(a) Isotopic energy distribution of fragments obtained from reaction ${}^{32}\mathrm{S}$ (220 MeV) + ${}^{12}\mathrm{C}$ at an angle ${\theta }_{\mathrm{lab}}=21.6^{\circ }$. Red solid line shows fitted Gaussian and arrow indicates the energy of the fragments as obtained from Viola systematics. (b) Isotopic angular distribution of fragments for the same reaction.

Figure 3

Energy distribution of fragments for the reactions ${}^{32}\mathrm{S}$ (200, 220 MeV) + ${}^{12}\mathrm{C}$ at an angle ${\theta }_{\mathrm{lab}}=21.6^{\circ }$. Red solid line shows fitted Gaussian and arrow represents the energy of the fragments as obtained from Viola systematics.

Figure 4

The average velocities of the fragments plotted in ${\mathrm{v}}_{\parallel }$ vs ${\mathrm{v}}_{\perp }$ plane at bombarding energies 200 and 220 MeV. The average velocities are denoted by semi open circles (Li), open triangles (Be), open stars (B), open squares (C), open inverted triangles (N), and open hexagons (O). The arrows correspond to the compound nucleus velocities.

Figure 5

Angular distribution of fragments obtained in the reaction ${}^{32}\mathrm{S}+{}^{12}\mathrm{C}$ at 200 and 220 MeV beam energy (denoted by circles and inverted triangles) as a function of c.m. angle.

Figure 6

Average $\langle Q\rangle$ value of the fragments at 200 and 220 MeV incident energy (represented by circles and inverted triangles, respectively) plotted as a function of c.m. angle.

Figure 7

Total cross section of different fragments obtained at incident energies 200 and 220 MeV. Red line represents corresponding EHFM result.

Figure 8

Cross-section ratio vs $Z$ plot of ${}^{32}\mathrm{S}$ (220 MeV) + ${}^{12}\mathrm{C}, {}^{32}\mathrm{S}$ (200 MeV) + ${}^{12}\mathrm{C}$, and ${}^{16}\mathrm{O}$ (116 MeV) + ${}^{28}\mathrm{Si}$ reaction (represented by filled blue circles, open black circles, and red triangles, respectively).

Figure 9

Ratio of oxygen and carbon yield as a function of excitation energy, the filled and empty circles represents $E_{\mathrm{lab}}=200$ and 220 MeV, respectively.