Abstract
The source transfer function has been measured in a natural uranium-light water moderated sub-critical assembly as a function of source frequency and position. A square wave input of fast neutrons from the D-T reaction was supplied by a SAMES type J accelerator suitably modified for the purpose. Prompt gamma radiation from fission, energy above 2.5 Mev was detected with a sodium iodide scintillation counter and the time variation of the detector output was recorded on a multi-channel analyser used in the time sequence storage mode and synchronised with the source pulsing frequency. By Fourier analysing the recorded waveform the source transfer function was found.Two group diffusion theory was used to determine the spatially dependent source transfer function for a system similar to the experimental one. The computer programs ATEST and GAMMARESFU, were written to calculate the neutron flux in the core and also prompt fission gamma rays response function outside the subcritical assembly at chosen frequency and detector position. The method gave good agreement with the experiment.
| Date of Award | 1978 |
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| Original language | English |
| Awarding Institution |
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Keywords
- transfer function
- subcritical system
- gamma radiation