Top and Bottom Counting Detectors for the ISS-CREAM experiment

Abstract

It is important to measure the cosmic ray spectrum to understand the origin, acceleration and propagation mechanisms of high-energy cosmic rays. The Cosmic Ray Energetics And Mass experiment will be launched in 2016 on the International Space Station (ISS-CREAM) to measure cosmic ray elemental spectra up to energies beyond the reach of balloon instruments. The main goal of the Top Counting Detector (TCD) and Bottom Counting Detector (BCD) is to separate electrons from protons using the difference between electromagnetic and hadronic shower shapes in the energy range of 300 GeV ∼ 800 GeV. The T/BCD consist of a plastic scintillator attached to 20 × 20 photodiodes. The active detection areas in the T/BCD are 500 × 500 mm 2 and 600 × 600 mm 2 , respectively. The TCD is located between the ISS-CREAM carbon target and its calorimeter, and the BCD is located below the calorimeter. Before integration with the payload, the T/BCD were assembled and conducted vibration and thermal vacuum tests to confirm the safety of the T/BCD under a space environment. The noise and gain of the T/BCD were tested with flight electronics, and the capability of the T/BCD to separate electrons from protons has been studied with a GEANT3 simulation. We present the design, construction, performance and simulation results of the T/BCD.

Cosmic Ray Energetics And Mass: from balloons to the ISS

“…They also provide a redundant cosmic ray trigger. Details of the TCD/BCD design and measured performances are presented elsewhere [9][10][11].…”