An intrinsic sensor(diameter 16 mm,thickness 300 μm) based on chemical vapor deposition derived polycrystalline diamond was developed.Ultra low dark current under 100 pA and high n/discrimination of 15.8 were obtained on this device,which enable it to be used for neutron detection in multi-radiation field.Moreover,the neutron sensitivity of this detector was characterized theoretically and experimentally.And for fast and ultra-fast neutron,the detection sensitivity is in the magnitude of 10 17 to 10 16 C cm 2 /n with good stability and negligible pump effect.All these results indicate that the as-prepared sensor to be ideal for fast and ultra-fast neutron monitoring,and it may pave the way to build neutron detector with low cost and large sensitive area with diamond.
LIU LinYueOUYANG XiaoPingZHANG ZhongBingZHANG JianFuZHANG XianPengZHONG YunHongWANG Wei
When neutron yield is very low,reconstruction of coding penumbra image is rather difficult.In this paper,low-yield（109）14 MeV neutron penumbra imaging was simulated by Monte Carlo method.The Richardson Lucy（R-L）iteration method was proposed to incorporated with Bayesian least square-Gaussian scale mixture model（BLS-GSM）wavelet denoising for the simulated image.Optimal number of R-L iterations was gotten by a large number of tests.The results show that compared with Wiener method and median filter denoising,this method is better in restraining background noise,the correlation coefficient Rsrbetween the reconstructed and the real images is larger,and the reconstruction result is better.
