• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Marine Chemistry >Calibration of RaDeCC systems for 223Ra measurements
【24h】

Calibration of RaDeCC systems for 223Ra measurements

机译：用于223Ra测量的RaDeCC系统的校准

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

RaDeCC (or radium delayed coincidence) counters have proved to be a fast and precise way to measure ~(224)Ra and ~(223)Ra in water samples. However, the calibration of these counters for ~(223)Ra has been problematic. Unlike standards prepared from ~(232)Th to calibrate ~(224)Ra-~(220)Rn measurements, standards prepared from ~(227)Ac for ~(223)Ra-~(219)Rn measurements decrease in the amount of ~(219)Rn they release with time. Here we develop a way to use the ~(232)Th calibration of the 220 channel efficiency to calibrate the 219 channel. We first consider the slightly different effects of delay and window opening time constants in the default RaDeCC system. These differences favor ~(220)Rn detection by about 3%. Next, we consider the effect of dead volume on the relative efficiencies. In a typical system, with a source volume in the range 100-300 ml, there is about a 3-8% lower predicted probability of ~(219)Rn decaying in the counting cell relative to ~(220)Rn. Thus, the absolute efficiency of the 219 channel should be about 6-11% lower than the efficiency of the 220 channel, depending on the dead volume of the system. We tested the effects of window time constants and dead volumes by altering these parameters in a known manner and correcting for the alterations. In this analysis we neglect the differences in alpha decay energy between the ~(219)Rn-~(215)Po pair and the ~(220)Rn-~(216)Po pair. These differences may increase slightly the efficiency of the 219 channel because of the higher alpha decay energies of ~(219)Rn-~(215)Po.
机译：RaDeCC（或镭延迟重合）计数器已被证明是测量水中样品中〜（224）Ra和〜（223）Ra的快速而精确的方法。但是，〜（223）Ra的这些计数器的校准存在问题。与〜（232）Th制备的用于校准〜（224）Ra-〜（220）Rn测量的标准品不同，~~（223）Ra制备的〜（223）Ra-〜（219）Rn测量的标准品减少了〜（219）Rn它们随时间释放。在这里，我们开发了一种使用220通道效率的〜（232）Th校准来校准219通道的方法。我们首先考虑默认的RaDeCC系统中延迟和窗口打开时间常数的影响略有不同。这些差异有利于〜（220）Rn检测约3％。接下来，我们考虑死体积对相对效率的影响。在典型的系统中，源体积在100-300 ml之间，相对于〜（220）Rn，计数单元中〜（219）Rn衰减的预测概率降低了约3-8％。因此，取决于系统的死体积，219通道的绝对效率应比220通道的效率低大约6-11％。通过以已知方式更改这些参数并校正更改，我们测试了窗口时间常数和死体积的影响。在此分析中，我们忽略了〜（219）Rn-〜（215）Po对和〜（220）Rn-〜（216）Po对之间的α衰变能量差异。这些差异可能会稍微提高219通道的效率，因为〜（219）Rn-〜（215）Po具有更高的alpha衰减能量。

著录项

  • 来源
    《Marine Chemistry》 |2013年第20期|130-137|共8页
  • 作者

    Willard S. Moore; Pinghe Cai;

  • 作者单位

    Department of Earth and Ocean Sciences, University of South Carolina, Columbia, SC 20208, USA,State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China;

    State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    Radium; RaDeCC; Calibration; Lucas cell;

    机译：镭;RaDeCC;校准;卢卡斯细胞;

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号