R & D of a Cosmic Ray Detector with High Energy Beams at CERN

我们对球载光纤电子望远镜（BETS）进行了加速器束流测试。探测器被转移到瑞士的CERN，并被照射到能量从5 GeV到100 GeV的电子束。这个能量区域对应于我们观测到宇宙射线电子的能量区域。该望远镜能够识别电子，并通过成像的簇射与纤维测量能量的发展。梁试验在西区SPS-T1/X5梁线上进行。在各种条件下辐照了近20万个电子，在数字记录磁带上记录了约5个GdR数据。实验是在CERN工作人员的大力支持下完成的。通过数据分析，我们证实BETS的性能如下：通过对簇射剖面成像成功地进行了电子选择，能量分辨率在15%~ 18%之间，角分辨率约为1度，利用1995年和1997年的气球数据，我们成功地导出了电子能谱。我们将通过质子束测试来确认抑制能力，并开发分析方法以获得对质子的更高抑制能力。

We have carried out accelerator beam tests for the balloon-borne electron telescope with scintillating fibers (BETS). The detector was transferred to CERN in Switzerland and was irradiated to the electron beams with energies from 5 GeV to 100 GeV. This energy region corresponds to the energy region in which we observed the cosmic-ray electrons. The telescope is capable to identify the electrons and measure the energies by imaging the shower developments with scintillating fibers. The beam tests were carried out at the SPS-T1/X5 beam line in the West Area. Nearly 200 thousands electrons were irradiated under various conditions and about 5 GBytes data were recorded on the digital recording tapes. The experiment was performed by excellent supports by the CERN staffs. The purpose of the test was completely accomplished within the scheduled dates.By the data analysis, we have confirmed the performance of BETS as following :The selection of electrons is successfully performed by imaging the shower profile.The energy resolution is in the range of 15% to 18%.The angle resolution is about 1 degree.We have successfully derived an electron energy spectrum from the balloon data in 1995 and 1997 by adopting the calibration results. We will confirm the rejection power by doing the proton beam tests and develop the analysis method to get higher rejection power against the protons.