补偿中子测井中与温度相关轻水热中子散射数据库的研制与应用

Development and application of temperature-dependent thermal neutron scattering data of light water for compensated neutron logging

补偿中子测井受到环境温度的影响,利用数值模拟计算来进行修正,但目前的理论计算程序MCNP缺乏水的精细温度相关的热中子散射数据库。为了解决蒙特卡罗模拟热中子散射S(α,β)模型只能求解特定温度条件下中子输运问题的局限性,基于热中子散射的S(α,β)原理,采用内插法得到不同温度下水的频谱分布、振动;在最新的ENDFB-VII.1数据库上,利用NJOY99程序制作了ACE格式的轻水热中子散射截面数据库。利用系列次临界基准题对数据的准确性进行了验证,不同数据库之间的计算结果及基准题的结果符合得很好。自制的数据应用于测井仪器中的温度效应修正,取得了较好的效果。

Compensated neutron logging is often affected by log perature correction for neutron log porosity by numerical simulation. environmental temperature, thus it is necessary to do tern In Monte Carlo simulation, the S（a,β）model of light water can only be used at some given temperature. Based on the principle of thermal neutron scattering, the frequency spectra of interpo lation with different temperature and the latest release of version VII of Evaluated Nuclear Data File（ENDF/B VII. 1}, a new fine ACE（a compact ENDF） formatted thermal neutron scattering database of light water was developed by NJ（）Y99 code. The vali dation of data were clone by a suite of criticality benchmarks, it is concluded that the results of benchmarks, the existing database and the newly developed database are in good agreement. A good result was achieved in temperature correction of well logging da ta with the new database.