Antiproton identification below threshold with the AMS-02 RICH detector

• 来源期刊: 中国物理C（英文版）
• 年，卷（期）: 2017,（5）
• 页码范围: 158-163
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1137/41/5/056001

摘要

The Alpha Magnetic Spectrometer (AMS-02),which is installed on the International Space Station (ISS),has been collecting data successfully since May 2011.The main goals of AMS-02 are the search for cosmic anti-matter,dark matter and the precise measurement of the relative abundance of elements and isotopes in galactic cosmic rays.In order to identify particle properties,AMS-02 includes several specialized sub-detectors.Among these,the AMS-02 Ring Imaging Cherenkov detector (RICH) is designed to provide a very precise measurement of the velocity and electric charge of particles.We describe a method to reject the dominant electron background in antiproton identification with the use of the AMS-02 RICH detector as a veto for rigidities below 3 GV.A ray tracing integration method is used to maximize the statistics of (p) with the lowest possible e-background,providing 4 times rejection power gain for e-background with respect to only 3％ of (p) signal efficiency loss.By using the collected cosmic-ray data,e-contamination can be well suppressed within 3％ with β ≈ 1,while keeping 76％ efficiency for (p) below the threshold.