Dt Neutron Source Engineering Simulation Undesired Neutron Research

The article analyzes the intention of the experimental study on the non-expected neutron and the importance significance in engineering simulation experiment. The non-expected neutron and non-expected signal have been parsed and defined. The effect of the experimental result has been carefully analyzed .In engineering simulation experiment, the non-expected neutron may come into being in the Monitoring the signal of the accelerator neutron sources and surroundings scattering and structure material of the detector. The neutron yield of d-T reaction is acquired through the associated a particle monitored. If the non-expected signal in the monitoring of the charged particle is not discriminated, which may be though that the non-expected neutron would bring in the neutron yield.The principle and method to measure d-T reaction neutron fluence rate with the associated particle method is introduced. The a particle spectrum is monitored with the associated particle method is analyzed. The factors to effect the neutron fluence rate are theoretically analyzed and calculated. The error source in measuring neutron fluence rate is gived.The efficiency of U-fission chamber is studied. The effect factors to detector are analyzed and experimentally studied. The effect of detector disturb and the shell of the detector and construction material is not distinct. The low absorb cross section material is used to 235U-fission chamber. The low Z material is used in experimental bracket and shielding material and the material is used less.The autogeny target neutron and pipeline neutron are monitored with associated particle method and long counter through changing different target foil. The effect of the autogeny target neutron is over ten times than that of the pipeline neutron. The effect of the autogeny target neutron relates to the target time being used. When the ratio of the proton(d-D) counter and a particle counter exceed the experimental need, the target must be changed in time. Generally, the share of the autogeny target neutron in d-T neutron source is less than one percent.In the engineering simulation experiment, the distance between the neutron source and the detector is close, the scattered neutron cannot directly measured through shielding from neutron source with shield cone. So, The distributing of the scattering background neutrons in the experiment hall is calculated with the MCNP/4A code. In the experiment, the scatteredbackground neutrons is studied with the shielding method and the scattered background neutrons in the experiment hall is eliminated from signal neutrons by the method of combining the shielding experiment's results with the MCNP/4A code calculation.