Beam test of a dual layer silicon charge detector (SCD) for the CREAM experiment

Abstract

The Cosmic Ray Energetics and Mass (CREAM) balloon-borne experiment is designed for direct measurement of high-energy cosmic rays. The experimental goal is to measure single-element fluxes of all cosmic-ray nuclei from hydrogen to iron with energies up to the "knee", or spectral index change near 1015 eV, observed in the all-particle spectrum. The dual layer Silicon Charge Detector (SCD) was designed to provide precise charge measurements. Each SCD layer has an active area of 77.9 cm × 79.5 cm and consists of 156 silicon sensors mounted on 24 ladders. Each sensor contains a 4 × 4 array of single-sided DC type silicon pixels with an active area of 2.1 cm2. The detector was flown on the second CREAM flight (December 2005-January 2006) and recovered successfully. The SCD was refurbished for the third CREAM flight and tested with high-energy electron and hadron beams at CERN. This paper reports on the performance of the SCD during the beam test. © 2007 Elsevier B.V. All rights reserved.