Technical Note: Characterization of the new microSilicon diode detector
Technical Note: Characterization of the new microSilicon diode detector
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DOI：
10.1002/mp.13710
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发表时间：
2019-07-31
期刊：
影响因子：
3.8
通讯作者：
Looe, Hui Khee
中科院分区：
文献类型：
--
作者：
Schoenfeld, Ann-Britt;Poppinga, Daniela;Looe, Hui Khee
目的研究新型微硅二极管探测器（60023）的剂量学特性，重点研究其在小野剂量学中的应用。已经量化了敏感体积的尺寸和围绕microSilicon的硅芯片的环氧树脂层的密度的影响，并将其与其前身（Diode E 60017）和microDiamond（60019，所有PTW-Freiburg，德国）进行了比较。方法在0.01~8.55戈伊剂量范围内研究了剂量线性关系，在0.13~0.86 m戈伊/脉冲剂量范围内研究了剂量依赖性。通过将测量的百分比深度剂量曲线与参考曲线（鲁什室）进行比较，确定有效测量点（EPOM）。输出比测量标称字段大小从0.5 × 0.5 cm（2）到4 × 4 cm（2）。相应的小场输出校正因子，k，推导出与塑料闪烁探测器作为参考。使用狭缝束几何形状确定横向剂量响应函数K（x）。结果MicroSilicon在8.55戈伊以下的低剂量和高剂量范围内均表现出线性剂量响应（R-2 = 1.000），在所研究的每脉冲剂量值内偏差仅为1%。发现EPOM位于前探测器表面下方（0.7 +/-0.2）mm处。微硅的导出k（在s（eff）= 0.55 cm时为0.960）与微金刚石的k（0.956）相似，而二极管E需要更大的校正（0.929）。与二极管E相比，微硅在小场中的这种改进的行为反映在略宽的K（x）中。此外，在敏感体积的边界处K（x）的负值的幅度已经减小。结论与前代产品相比，微晶硅具有更高的灵敏度和更小的剂量依赖性。轮廓测量表明，微硅引起离轴测量的扰动较小。它特别适合于小场输出因子和轮廓测量。
Purpose Dosimetric properties of the new microSilicon diode detector (60023) have been studied with focus on application in small-field dosimetry. The influences of the dimensions of the sensitive volume and the density of the epoxy layer surrounding the silicon chip of microSilicon have been quantified and compared to its predecessor (Diode E 60017) and the microDiamond (60019, all PTW-Freiburg, Germany). Methods Dose linearity has been studied in the range from 0.01 to 8.55 Gy and dose-per-pulse dependence from 0.13 to 0.86 mGy/pulse. The effective point of measurement (EPOM) was determined by comparing measured percentage depth dose curves with a reference curve (Roos chamber). Output ratios were measured for nominal field sizes from 0.5 x 0.5 cm(2) to 4 x 4 cm(2). The corresponding small-field output correction factors, k, were derived with a plastic scintillation detector as reference. The lateral dose-response function, K(x), was determined using a slit beam geometry. Results MicroSilicon shows linear dose response (R-2 = 1.000) in both low and high dose range up to 8.55 Gy with deviations of only up to 1% within the dose-per-pulse values investigated. The EPOM was found to lie (0.7 +/- 0.2) mm below the front detector's surface. The derived k for microSilicon (0.960 at s(eff) = 0.55 cm) is similar to that of microDiamond (0.956), while Diode E requires larger corrections (0.929). This improved behavior of microSilicon in small-fields is reflected in the slightly wider K(x) compared to Diode E. Furthermore, the amplitude of the negative values in K(x) at the borders of the sensitive volume has been reduced. Conclusions Compared to its predecessor, microSilicon shows improved dosimetric behavior with higher sensitivity and smaller dose-per-pulse dependence. Profile measurements demonstrated that microSilicon causes less perturbation in off-axis measurements. It is especially suitable for the applications in small-field output factors and profile measurements.