Abstract:
Cosmic rays are used for the calibration of the Veto detector at ETF (External Target Facility) in HIRFL-CSR (Cooling Storage Ring of Heavy Ion Research Facility in Lanzhou). The work primarily involves two parts: position calibration and time calibration. Position calibration can provide the precise location of particle hits on the Veto detector, while time calibration can establish a uniform standard for the detection of the moment when a particle hits the detector. The information of hit position and hit time is crucial for identifying and excluding events of charged particles incident on the neutron wall detector, providing important support for the achievement of the physical objectives of the neutron wall detector. During the calibration process, the Veto detector's position resolution FWHM (Full Width at Half Maximum), was determined to be 2.53 cm, and the time resolution FWHM, after the normalization of the times of all unit bars, was found to be 1.09 ns.