Hunter D, Dratz A F, Rohrer R H, Coberly J C
J Nucl Med. 1975 Oct;16(10):952-4.
The radioassay of very small 125I samples in both conventional and side-hole well crystals has been investigated. Using a multichannel analyzer, the source was counted at various positions within these well crystals. The effect of using a single-channel pulse-height analyzer was simulated by summing the counts over a 24-keV range across the primary peak, over a 30-keV range across the sum-coincidence peak, and over a 56-keV range across both peaks. In all crystals the primary peak was independent of sample position within the well over a range of several centimeters. The contribution of the sum-coincidence peak varied significantly with sample position in the conventional well crystals. With the side-hole crystal the counts contributed by the sum-coincidence peak exhibited a 2-cm plateau.
对常规晶体和侧孔井晶体中极少量¹²⁵I样本的放射性测定进行了研究。使用多通道分析仪，在这些井形晶体的不同位置对源进行计数。通过在主峰上跨24 keV范围、在和符合峰上跨30 keV范围以及在两个峰上跨56 keV范围求和计数，模拟了使用单通道脉冲高度分析仪的效果。在所有晶体中，主峰在几厘米范围内与井内样本位置无关。在常规井形晶体中，和符合峰的贡献随样本位置有显著变化。对于侧孔晶体，和符合峰贡献的计数呈现出2厘米的平稳段。
