Simulation of the Experimental Program with Ultracold Neutrons at the PIK Reactor

In this paper, we model a complex for research based on a high-intensity source of ultracold neutrons at the PIK reactor. Superfluid helium is used as a converter of cold neutrons into ultracold ones. A model, which includes a source, a neutron-guide system, and experimental setups taking into account their real location in the main hall of the reactor is developed using the Monte Carlo method. Based on the simulation, it is found that in a closed source chamber, it is possible to obtain an ultracold-neutron density of 3.5 × 10 3 n/cm 3 . By means of calculations, the values of the sensitivity of the measuring setups for the search for the electric dipole moment of the neutron and for the measurement of the neutron lifetime at the PIK reactor are obtained. For the experiment on searching for the electric dipole moment of the neutron, it is found that the density of ultracold neutrons in the chambers of the spectrometer can be 200 n/cm 3 , which is 50 times better than that in the source at the Institute Laue-Langevin. For the experiment on measuring the neutron lifetime, it is found that the counts of the neutron detector can be increased by a factor of 16 compared to similar measurements at the reactor at the Institute Laue-Langevin. This indicates the possibility of achieving a statistical accuracy of the measurement result of 0.2 s at a similar measurement duration.