INES Time-of-Flight Spectrometer

A method for determining the start pulse for the time-of-flight technique has been developed, significantly improving the accuracy of temporal alignment with the proton beam pulse. The energy spectrum of the pulsed neutron source RADEX has been measured and compared with the results of simulations. The procedure for determining the shape of the neutron pulse over time is described based on the measured shape of the proton beam pulse when neutrons are slowed down in the target. A method for absolute calibration of the spectrometer is outlined, taking into account the effect of neutron energy changes due to multiple elastic scattering of neutrons in the sample. A procedure for recovering neutron capture cross-sections by a nucleus during multiple elastic scattering of neutrons in the sample has been developed. Calibration measurement results for the neutron capture cross-section by Au on the time-of-flight spectrometer at the INES facility are presented. The measured cross-sections are compared with calculated cross-sections based on known resonance parameters and with cross-sections previously obtained in experiments using a thin sample.