A routine method for accurate neutron energy measurements in the range 1-20 MeV

A routine method for accurate neutron energy measurements using a time-of-flight spectrometer is described. The applicability of the method has been investigated by measuring the energy of different neutron groups in the range 1-20 MeV. The neutrons were produced at the Studsvik 6 MV pulsed Van de Graaff accelerator, using the 7Li(p, n)7Be, 9Be(d, n)10B and 11B(d, n)12C reactions. The energy of the narrow resonance in the 12C total neutron cross section at approx.=2078 keV was determined in a transmission measurement, and the result of 2077.6 +- 1.8 keV was used as a calibration point. The uncertainties in the measured neutron energies were estimated to be 0.1 - 0.3% over the energy range mentioned. (orig.)