基于MCNP和能谱法对γ射线吸收实验的改进

The improvement of the experiment about the absorption of gamma ray based on the MCNP and the energy spectrum method

针对一般的测量物质线性吸收系数实验的缺点,文章利用Monte Carlo N Particle Transport Code(MCNP)和全能峰面积法模拟计算了不同实验条件下物质γ射线吸收的线性吸收系数,计算与公认值的偏差.通过使偏差在较小的合理范围内,并与其它方法对比,找出了合适的实验条件,使测量装置易于调试,可得射线能量信息,而且比计数法的准确度高,探测效率较高,以此改进并简化了实验.

In view of the defect of the traditional measurements of materials linear absorption coefficients,in this work the linear absorption coefficients of gamma ray in different experimental conditions are simulated and calculated using the Monte Carlo N Particle Transport Code(MCNP)and the method of full energy peak area,and the deviations of the coefficients from the recognized values are also calculated.The appropriate experimental condition is obtained by reducing the deviation to a reasonable scope and contrasting with other methods.As a result,the approved measuring equipment which is easy to adjust is able to obtain the information about radiation energy.It offers a better accuracy and higher detection efficiency compared with the counting method.