Silicon Charge Detector

SCD, dedicated to measuring the charge of cosmic rays up to Z=26, is placed as the outmost layer to avoid as much as possible fragmentation of high energy particles. Two to three position-sensitive double planes of silicon detectors are allocated on each of the five faces. 

At most 10 single-sided micro-Strip Silicon Detectors (SSDs) is bonded in a row as a ladder. Ladders on alternative planes are placed orthogonally in order to locate accurate position of the incoming particle. The pitch size and the width of the strips of SSDs have been optimized for more precise charge measurement.