Design of Wide-energy-range Neutron Calorimeter for Nuclear Collisions in the Korea Rare-isotope Accelerator

Abstract

for measuring high-energy neutrons. The detection eciency is estimated to be about 88% for neutron energies larger than 50 MeV and decreases to 78% at 30 MeV. We have estimated the energy resolution as a function of the incident energy based on the time-of-flight method. Assuming an ideal detector performance with null time resolution, the relative energy resolution decreases as the incident neutron energy increases. However, under a more realistic situation with a finite time resolution for the detector, the energy resolution monotonically increases with increasing the neutron energy, following a logarithmic function. Imposing an energy resolution of better than 3% at the highest neutron energy, we find the nominal position of the hybrid calorimeter to be 15 m from the target for a time resolution of 1.0 ns, but the detector needs to be free to move closer to or farther from the target, depending on the physics goal.