arXiv subjects

T. Bhattacharjee

Publications and source records attributed to T. Bhattacharjee.

22 records · Page 2Linked to original sources

arXiv2007

Characterization of fragment emission in ^{20}Ne (7 - 10 MeV/nucleon) + ^{12}C reactions

The inclusive energy distributions of the complex fragments (3 $\leq$ Z $\leq$ 7) emitted from the bombardment of ^{12}C by ^{20}Ne beams with incident energies between 145 and 200 MeV have been measured in the angular range 10$^{o} \leq θ_{lab} \leq$ 50^{o}. Damped fragment yields in all the cases have been found to be the characteristic of emission from fully energy equilibrated composites. The binary fragment yields are compared with the standard statistical model predictions. Enhanced yields of entrance channel fragments (5 $\leq$ Z $\leq$ 7) indicate the survival of orbiting-like process in ^{20}Ne + ^{12}C system at these energies.

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arXiv2005

Survival of orbiting in $^{20}$Ne (7 - 10 MeV/nucleon) + $^{12}$C reactions

The inclusive energy distributions of fragments with Z $\geq$ 3 emitted from the bombardment of $^{12}$C by $^{20}$Ne beams with incident energies between 145 and 200 MeV have been measured in the angular range $θ_{lab} \sim$ 10$^\circ$ - 50$^\circ$. Damped fragment yields in all cases have been found to be characteristic of emission from fully energy equilibrated composites; for B, C fragments, average Q-values, $ $, were independent of the centre of mass emission angle ($θ_{c.m}$), and the angular distributions followed $\sim$1/sin$θ_{c.m}$ like variation, signifying long life times of the emitting di-nuclear systems. Total yields of these fragments have been found to be much larger compared to the standard statistical model predictions of the same. This may be indicative of the survival of orbiting like process in $^{12}$C + $^{20}$Ne system at these energies.

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arXiv2004

Dissipation of angular momentum in light heavy ion collision

The inclusive energy distributions of fragments (4$\leq$Z$\leq$7) emitted in the reactions $^{16}$O (116 MeV) + $^{27}$Al, $^{28}$Si, $^{20}$Ne (145 MeV) + $^{27}$Al, $^{59}$Co have been measured in the angular range $θ_{lab} $= 10$^\circ$ - 65$^\circ$. Fusion-fission and deep inelastic components of the fragment emission have been extracted from the experimental data. The angular mometum dissipations in fully damped deep inelastic collisions have been estimated assming exit channel configuration similar to those for fusion-fission process. It has been found that, the angular momentum dissipations are more than those predicted by the empirical sticking limit in all cases. The deviation is found to increase with increasing charge transfer (lighter fragments). Qualitatively, this may be due to stronger friction in the exit channel. Moreover, for the heavier system $^{20}$Ne + $^{59}$Co, the overall magnitude of deviation is less as compared to those for the lighter systems, {\it i.e.}, $^{16}$O + $^{27}$Al, $^{28}$Si, $^{20}$Ne + $^{27}$Al. This may be due to lesser overlap in time scales of fusion and deep inelastic time scales for heavier systems.

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arXiv2002

Dissipative collisions in $^{16}$O + $^{27}$Al at E$_{lab}$=116 MeV

The inclusive energy distributions of fragments (3$\leq$Z$\leq$7) emitted in the reaction $^{16}$O + $^{27}$Al at $E_{lab} = $116 MeV have been measured in the angular range $θ_{lab} $= 15$^\circ$ - 115$^\circ$. A non-linear optimisation procedure using multiple Gaussian distribution functions has been proposed to extract the fusion-fission and deep inelastic components of the fragment emission from the experimental data. The angular distributions of the fragments, thus obtained, from the deep inelastic component are found to fall off faster than those from the fusion-fission component, indicating shorter life times of the emitting di-nuclear systems. The life times of the intermediate di-nuclear configurations have been estimated using a diffractive Regge-pole model. The life times thus extracted ($\sim 1 - 5\times 10^{-22}$ Sec.) are found to decrease with the increase in the fragment charge. Optimum Q-values are also found to increase with increasing charge transfer i.e. with the decrease in fragment charge.

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