RADIATION DETECTOR

PURPOSE:To surpress expansion and contraction, and warp of a detection element base plate caused by thermal effect thereof by loading a signal processing circuit on a circuit base plate independently of a detection part, and by constituting the circuit base plate within longitudal width in which the detection elements are arranged. CONSTITUTION:A signal processing circuit part 8 containing a primary stage amplifier circuit, a pulse amplifier circuit, a comparator circuit and a pulse counting circuit, is loaded on a circuit base plate 9, and the circuit base plate 9 is constituted within longitudal width which is independent of a radiation detection part and in which detection elements 1 are arranged. The detection elements 1 is surrounded by a radiation shielding body 4 and a detection element table 3 which are made of a metallic material, and thereby mechanical protection and electromagnetic shielding are well maintained. Also, expansion and contraction, and warp of a detection element base plate 2 can be absorbed by constitution that the radiation detection part and the circuit base plate 9 are separated and independent one another, and by elasticity of a flexible base plate 6.