中文摘要：

尽管多道能谱中X射线与γ射线重叠区内峰下的计数常具有能够提供重要信息的可能，但有时因这种重叠能区难于解谱而被摒弃。能量依赖的探测效率会使X射线峰出现左右不对称。探测器对X及γ射线响应形状的准确描述，及将已知信息在拟合中作为约束项的应用是精确分解出多道能谱中重叠区各成份计数的保障。充分利用RooFit软件包，建议了一种X射线峰形描述方式：利用洛伦兹函数描述其本征形状并与探测效率相乘，之后与分辨函数卷积以描述探测后的形状。测试显示放入与拟合出的峰下计数在统计误差范围内一致。所建议的方法及提供的代码可作为X及γ射线重峰区的解谱参考。

英文摘要：

Background： Although counts under peaks in overlap region of multi-channel spectrum from X- and γ-rays can provide useful information, they are usually discarded because of much difficulty in being unfolded. The line-shape of X-ray peak could be asymmetric in left and right side caused by an energy-dependent detector efficiency Purpose： To accurately fit out the shapes for the counts under the peaks, X- and γ-ray shapes should be described accurately, and all known information should be used as constraints for reliable results. Methods： With RooFit package, a method to describe the X-ray shape is proposed： take its intrinsic shape of X-ray described by a Lorentz function and multiplied by a detector efficiency function, then convoluted with a resolution function. Results： The results tested with the codes included in this paper show： the events number of input and output agrees within their statistical errors checked even with very heavily overlapped peaks unfolded with branch ratio constraint method. Conclusion： The method and the code introduced in this paper are feasible, and they can be used as an example to unfold overlap regions in X- and γ-ray multi-channel spectrum.