A Silicon-Emulsion Shower Counter for Cosmic Ray High Energy Electron Observation

An instrument consisting of a combination of position sensitive silicon detectors, nuclear emulsion plates and lead plates is proposed for measurement of the energy of primary cosmic ray electrons with the energy of lower than 30 GeV. As position sensitive detector, two dimensional Si(Li) circular detectors with sensitive area of 38.5 cm2 have been fabricated and build-up curves (transition curves) of deposited energy in the detector versus thickness of lead plate for high energy electron beams are presented as fundamental data for design of such an instrument.