Background deduction of the Chang’E-1 gamma-ray spectrometer data
Background deduction of the Chang’E-1 gamma-ray spectrometer data
复制标题
嫦娥一号伽玛能谱仪数据背景扣除
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
Z. Ouyang
中科院分区：
文献类型：
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作者：
Liyan Zhang;Chunlai Li;J. Liu;Yongliao Zou;Z. Ouyang
利用伽马射线能谱仪(GRS)探测月球表面的元素丰度和分布。为了获得元素丰度，获取除月球伽马射线之外的本底伽马射线是至关重要的。因此，GRS将按计划观测地月转移过程中的背景光谱。但实际上，GRS在飞向月球的过程中并没有打开。在CE-1探测器完成为期一年的任务后，GRS于2008年11月21-22日对背景数据进行了测试。作者确实利用GRS在200公里轨道高度获得的2105小时可用伽马射线谱和在GRS背景试验中获得的5小时以上的伽马射线谱，对本底推算方法进行了研究。最后的研究结果表明，对于元素U、K和Th，采用CE-1GRS像素中的最小计数来扣除背景的方法是最优的。该方法适用于计数速率最小的像素点的元素丰度为0μg/g，且月球上连续本底计数恒定的情况。基于本底演绎的方法，计算了U、K和Th的全能峰计数。
Gamma-ray spectrometer (GRS) is used to detect the elemental abundances and distributions on the lunar surface. To derive the elemental abundances, it is vital to acquire background gamma rays except lunar gamma rays. So GRS would observe background spectra in the course of earth-moon transfer on schedule. But in fact, GRS was not switched on in the course of flying toward the moon. After the CE-1 probe finished one-year mission, GRS carried out a test on background data on November 21–22, 2008. The authors did conduct research on the methods of background deduction using 2105 hours of usable gamma-ray spectra acquired at the 200-km orbital height by the GRS and more than 5 hours of gamma-ray spectra acquired in the GRS background test. The final research results showed that the method of deducting the background using the minimum counts in the CE-1 GRS pixels is optimal for the elements, U, K and Th. The method applies to such a case that the elemental abundances in the pixel with the minimum counting rate are 0 μg/g and the continuum background counts are constant over the Moon. Based on the method of background deduction, the full energy peak counts of U, K, and Th are calculated.