Massillon-JL G, Minniti R, Soares C G, Maryanski M J, Robertson S
Ionizing Radiation Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Appl Radiat Isot. 2010 Jan;68(1):144-54. doi: 10.1016/j.apradiso.2009.08.016. Epub 2009 Sep 3.
The properties of a new polymer gel with two sensitivities, made specifically for high-dose-gradient dosimetry, were investigated. The measurements were performed at NIST using a 1cmx1cm calibrated (60)Co field, and a 1cm active diameter (90)Sr/(90)Y beta particle source. A high-resolution laser CT scanner was used to quantify the response. The results show that the high-sensitivity gel responds linearly to the absorbed dose for doses from 0.5 up to 15Gy, while the low-sensitivity one is linear up to 225Gy. For both radiation types, the gel response remains stable in time up to a month after the irradiation. The response of the gel was found to have no dose rate dependence for dose rates ranging from 3.7 to 15mGy/s. Within the measurement uncertainty, the gel response is more sensitive for beta particles than high energy photons.
研究了一种专门为高剂量梯度剂量测定法制备的具有两种敏感性的新型聚合物凝胶的特性。测量在国家标准与技术研究院（NIST）进行，使用的是1cm×1cm校准的钴 - 60场以及活性直径为1cm的锶 - 90/钇 - 90β粒子源。使用高分辨率激光CT扫描仪对响应进行量化。结果表明，高敏感性凝胶在0.5至15Gy剂量范围内对吸收剂量呈线性响应，而低敏感性凝胶在高达225Gy时呈线性响应。对于两种辐射类型，凝胶响应在辐照后长达一个月的时间内保持稳定。发现凝胶响应在3.7至15mGy/s的剂量率范围内与剂量率无关。在测量不确定度范围内，凝胶对β粒子的响应比对高能光子更敏感。
