| Popis: |
Fusion data validation requires experiments to be conducted with sources capable of delivering neutron spectra closer to that of a fusion machine. (D,T) driven tokamaks under fabrication, which are the forerunner of the near fusion machines, incorporate medium and medium heavy elements for their fabrication. The presence of these materials result in absorption, scattering and other nuclear reactions, which will alter the virgin neutron spectra. At the LOTUS facility, 14 MeV Haefely neutron generator is used for fusion blanket studies. This generator employs cooling water, silicon oil, polyethylene and several medium heavy elements. The presence of lighter elements may significantly change the neutron spectra, studies are therefore conducted by using Cd or B4C absorbers held in front of the generator. It is experimentally found that by using 1 mm Cd or 2.6 mm thick B4C, the reaction rates for higher threshold detectors are affected at the most by 11%, whereas the Au foil response is reduced by a factor of 1.4 and 3.5 respectively. |
