Calibration of ophthalmic applicators at NIST: a revised approach.
Calibration of ophthalmic applicators at NIST: a revised approach.
复制标题
NIST 眼科涂药器的校准：修订方法。
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
Christopher G. Soares
中科院分区：
文献类型：
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作者：
Christopher G. Soares
提出了一种修正的方法来测量从β粒子发射眼科施源器的表面吸收剂量的问题。所选择的技术采用外推室配备了一个4毫米直径的收集电极，使电流测量在空气间隙从0.08至0.20毫米，在0.02毫米的间隔。这些数据产生电流和空气间隙之间的线性关系，其斜率用于确定源中心区域的平均表面吸收剂量率。对于源表面上的活性分布的其他信息，使用校准的辐射变色染料膜的放射自显影进行分析，以绘制整个施用器表面的剂量率曲线。实验不同的几个参数的外推室测量，包括收集电极面积，电压梯度，使用的空气间隙的范围，和入口箔材料，进行了说明。还处理的是校准，并说明使用，辐射变色染料膜源剖析。确定校正因子的外推室测量的实验进行了说明，并与这些测量的不确定性的评估。
A revised approach to the problem of measuring a surface-absorbed dose from beta-particle-emitting ophthalmic applicators is presented. The technique chosen employs an extrapolation chamber equipped with a 4-mm-diam collecting electrode to make current measurements at air gaps from 0.08 to 0.20 mm at 0.02-mm intervals. These data yield a linear relationship between current and air gap, the slope of which is used to determine average surface-absorbed-dose rate over the central area of the source. For additional information about the distribution of the activity over the source surface, autoradiographs using calibrated radiochromic dye films are analyzed to map the dose-rate profile across the surface of the applicator. Experiments varying several parameters of the extrapolation chamber measurement, including collecting electrode area, voltage gradient, range of air gaps used, and entrance foil material, are described. Also treated are calibrations of, and a description of the use of, radiochromic dye films for source profiling. Experiments for determining correction factors for the extrapolation chamber measurements are described, and an assessment of the uncertainties associated with these measurements is given.