放射性束弹性散射实验中的一种位置校准方法

A Method of Detector Misalignment Correction for an Elastic Scattering induced by the Radioactive Beams

在弹性散射实验中，探测器的位置校准是非常重要的。结合兰州放射性束流线（RIBLL）的实际情况，以低能轻炮弹在重靶上的弹性散射截面在前角区为卢瑟福散射的事实为依据，发展了一种简单而有效的位置校准方法。通过蒙特卡洛模拟来检测弹性散射角分布与不同方向上位置未校准时的依赖关系。该方法成功地应用在7Be与重靶的弹性散射实验中，得到了正确的微分截面角分布。

In a typical nuclear elastic scattering experiment, differential cross section is very sensitive to the scattered angle and therefore the main source of systematic errors come from a millimetric uncertainties in the position measurement of detectors. A method for detector misalignment correction has been successfully applied to the elastic scattering of ~Be on Pb target at Elau=17.9 MeV/u at Radioactive Ion Beam Line in Lanzhou （RIBLL） at Heavy Ion Research Facility in Lanzhou （HIRFL）. The correction method is based on the fact that the ratio of elastic scattering and Rutherford cross sections should be independent of scattering angle 0, and equal to unity for very forward angles. A Monte Carlo simulation was performed to examine the angular distribution of cross sections for a given shift of detector position.