Measurement of Time Resolution of Scintillation Detectors with EQR-15 Silicon Photodetectors for the Time-of-Flight Neutron Detector of the BM@N Experiment

To study the dependence of the equation of state of high-density nuclear matter on the term characterizing the isospin (proton–neutron) asymmetry of nuclear matter, it is necessary to measure azimuthal flow of neutrons as well as azimuthal flow of charged particles from a dense nuclear matter in the nuclear–nuclear collisions. For this purpose, the Institute for Nuclear Research (Russian Academy of Sciences) is developing a new high-granular neutron detector that will be used in the BM@N experiment at the extracted beam of the Nuclotron accelerator at the Joint Institute for Nuclear Research (JINR, Dubna). This detector will identify neutrons and measure their energies in the heavy-ion collisions up to 4 GeV per nucleon. This article presents the results of measurements of the time resolution and light yields of samples of scintillation detectors with sizes 40 × 40 × 25 mm³ that will be used in a neutron detector based on the currently available fast plastic scintillator manufactured by JINR using an EQR15 11-6060D-S photodetector for light readout. For comparison, the results of measurements for a detector of the same size with a EJ-230 fast scintillator and with the same type of photodetector are given. The measurements were made on cosmic muons as well as on the Pakhra electron synchrotron of the Lebedev Physical Institute of the Russian Academy of Sciences located in Troitsk, Moscow.