DirFis: A hybrid silicon and PPAC detector array for direct reaction and fission coincidence measurements

Abstract: To further study the heavy-ion nuclear reaction mechanisms and fission of actinide nuclides by using the surrogate reaction method, a compact and efficient hybrid detector array for coincidence measurements of the beam-like particles and fission fragments has been developed and tested online. This detector array consists of four silicon strip detector telescopes and two parallel-plate avalanche counters. For the near-barrier \(^{7}\mathrm{Li} + ^{238}\mathrm{U}\) reaction, the fission fragments correlated with the beam-like \(^{6}\mathrm{He}\) particles originating from the transfer reaction were confirmed by analyzing the folding angle. The fission barrier height for the short-lived actinide nucleus \(^{239}\mathrm{Np}\), produced in the \(1p\) stripping channel, was extracted from its fission probability. The deduced value shows a good agreement with the existing literature data.