The fusion-fission process in the reaction $^{34}$S + $^{186}$W near the interaction barrier
Résumé
The reaction 34S + 186W at Elab=160 MeV was investigated with the aim of diving into the features of the
fusion-fission process. Gamma rays in coincidence with binary reaction fragments were measured using the high efficiency
gamma-ray spectrometer ORGAM at the TANDEM Accelerator facility of I.P.N., Orsay, and the time-of-flight spectrometer
for fission fragments (FF) registration CORSET of the Flerov Laboratory of Nuclear Reactions (FLNR), Dubna. The coupling
of the ORGAM and CORSET setups offers the unique opportunity of extracting details for characterizing the fusion-fission
process and gives information regarding production of neutron-rich heavy nuclei. The FF-$\gamma$ coincidence method is of better
use then the $\gamma$ - $\gamma$ coincidence method when dealing with low statistic measurements and also offers the opportunity to
precisely correct the Dopler shift for in-flight emitted gamma rays.
Evidence of symmetric and asymmetric fission modes were observed in the mass and TKE distributions, occurring due to
shell effects in the fragments. Coincident measurements allow for discrimination between the gamma rays by accepting a
specific range within the mass distribution of the reaction products. Details regarding the experimental setup, methods of
processing the acquisitioned data and preliminary results are presented.