HPGe伽马谱仪的源峰探测实验结果分析

HPGe伽马谱仪的源峰探测实验结果分析在双对数坐标下同时也可以看出在能量大于200keV效率与能量大致成线性关系形式，通过origin8计算给出拟合结果。.1标准源质质量g活度9误差活度(1σ)Bq2543273活度4.1.2实验计算半衰期活度A0日期与实验日期31d=0.0849y0,T1(4.1(4.1).2.2效率计算缓冲器(MCB)和计算机对多道分析器进行了仿真，具有强大的功能和灵活性。ii6(4.1)A=hCgi(4.2)修正的峰总计数是所有峰道址的总计数之和但是不包括峰道址之外的背景A=3Cagili(4.3)A=AA=Anag(hl+1) 净面积的的不确定度是由修正的峰总计数的不确定度的平方根总和以及修正的背景的权重误差所决定的。背景的不确定度的权重是由修正峰宽度和用来计算修正背景的道址数的比率来确定。所以净峰面积的不确定度为：=A+B(hl5)(hl5)Anag6hl+1(4.5)可以计算出探测器的源峰探测效率。在寻峰过程中可以看到有偶然符合相加效i斯展宽处理，所以模拟出的全能峰几乎没有展宽。其输出文件(见附录2)中的的序号E(keV)实验效率(5cm)实验误差MCNP(6.5cm)MCNP误差180.970.021331.36E-040.022284.72E-052121.920.036389.63E-050.036016.00E-053245.030.029371.96E-040.030455.52E-054276.740.02883.31E-040.028095.30E-055303.230.026661.82E-040.02625.12E-056356.420.024238.65E-050.023424.84E-057384.250.023672.25E-040.022184.71E-058444.370.019143.17E-040.019924.46E-0596620.015612.43E-050.014843.85E-05779.190.013028.59E-050.013173.63E-05867.650.011951.82E-040.012253.50E-05964.350.011247.98E-050.011473.39E-051112.340.010357.10E-050.010313.21E-0512000.009833.13E-0513000.009293.05E-0514000.008812.97E-0515000.008352.89E-05序号123456789E(keV)80.95 121.89245.01276.71303.22356.41384.23444.35661.98779.17867.64964.311112.32 1200 130014001500实验效率(15cm)实验误差MCNP(17.3cm)MCNP误差0.004484.42E-050.00462.14E-050.007593.04E-050.007462.73E-050.006596.77E-050.006662.59E-050.006241.18E-040.006182.50E-050.005955.97E-050.005842.43E-050.005242.87E-050.005252.30E-050.004977.35E-050.004972.25E-050.004441.22E-040.004482.13E-050.003367.96E-060.003381.85E-050.002943.42E-050.003041.73E-050.00266.24E-050.002831.66E-050.002512.65E-050.002621.61E-050.002372.37E-050.002391.52E-050.002271.51E-050.002141.47E-050.002031.43E-050.001931.40E-05序号123456789E(keV)80.94121.88245.01276.72303.19356.4384.22661.97779.17867.62964.32100011001200130014001500实验效率(25cm)0.001960.003310.002950.002720.002640.002380.002280.001520.001380.001250.00119实验误差3.16E-052.04E-054.47E-058.53E-054.18E-051.91E-054.90E-055.35E-061.96E-054.12E-051.61E-05MCNP(26.8cm)0.002040.003310.003020.002820.002660.00240.002290.001560.001390.00130.001210.001190.001120.001070.001019.55E-049.08E-04MCNP误差1.43E-051.82E-051.74E-051.68E-051.63E-051.55E-051.51E-051.25E-051.18E-051.14E-051.10E-051.09E-051.06E-051.03E-051.00E-059.77E-069.53E-06通过实验数据在坐标系下做出实验效率随能量变化关系图，如下图所示：00rgykeVm 00yyee0Energy/keV参数对探测效率也有很大影响。探测器的直径决定了源对探测器所张开的立体mycneycne在MCNP模拟过程如果没有对探测器几何尺寸进行修正，则在低能区模拟0.0.040.030.020.010500cyncynee0ergy4.7模拟源距17.3cm时探测效率与能量关系图 0Energy/keV探测效率的曲线拟合j0 3025201510eexperimentfittingcurvey=exp(a*(ln(x))^2+b*ln(x)+c)0.98898StandardError0.65272-3.72526EquationAdj.R-Squareexpexpexp0.064110.79022.42284cValue04000400 007006005004003002eexperimentfittingcurvey=exp(a*(ln(x))^2+b*ln(x)+c)0.99692StandardError0.03360.41831.27791EquationAdj.R-SquareBBBValue-0.060370.03015-3.3454c004000004000Energy/keV0.00300.00280.0026experiment0.00300.00280.0026Equationy=exp(a*(ln(x))^2+b*ln(x)+c)Adj.R-Square0.987460.0024ValueStandardErrorBa-0.019290.073570.0022yBb-0.441750.89154ycnBc-2.802532.7013cne0.0020e0.00180.00160.00140.00120.00102003004005006007008009001000曲线的拟合程度较好能够反映出数据的整体变化。在低能区(<200keV)，由于需要改进的地方。4.3.2探测器死层对效率的影响别是在低能下(<100keV)，死层和外包层的铝层对低能伽马光子的吸收特别强cLideadcLideadlayer2mmLideadlayer1.5mmLideadlayer1mmexperimentynecie0eV1.5mm，2mm时探测效率随能量变化同实验值的比较