6 - SOLID CONDUCTION COUNTERS

Abstract

Publisher Summary This chapter discusses solid conduction counters. According to the current theory of the solid state, a perfect homopolar crystal consists of a regular array of atoms arranged according to the appropriate crystal structure. The theory then predicts that when the possible electronic energy levels of such a system are all completely filled and when an appreciable gap separates the next vacant level from the highest completely-filled level, the material will be an insulator. The existence of impurities or defects, of interstitial atoms or vacant sites, will disturb the regular periodicity of the crystal lattice. Theoretically, this leads to the existence of discrete localized states in the forbidden energy gap. If these states are normally occupied, the system can be excited thermally or otherwise yield conduction electrons. Currently, no entirely satisfactory material for the manufacture of solid conduction counters exists; in addition, there are enormous variations in the counting response of different specimens of the same material.