SCANNER FOR CHECKING SPATIAL DISTRIBUTION OF POWER OF GAMMA-RAY EMISSION IN ACTIVE ZONE OF URANIUM-GRAPHITE REACTOR

FIELD: remote control of nuclear assemblies removed from service. ^ SUBSTANCE: scanner has movable detecting unit. Detecting unit has gamma-ray emission detector made in form of ionization chamber provided with grid. Detector is connected with input of converter. Output of converter communicates with receiver through connecting cable. Detector controls replacement of detecting unit. Receiver is located outside active zone of reactor. Collecting electrode of chamber is connected with input of electrometric logarithmic amplifier made on the base of operational amplifier with logarithmic transmission function. Output of operational amplifier is connected with first input of adder. Second input of adder is connected with base of n-p-n transistor. Transistor's collector is grounded. Ic current runs through the base of transistor in straight direction. Value of Ic meets the condition of 0,01Icm>=IcIco, where Icm is maximal admitted direct current for transistors of this type; Ico is back current of collector. Output of adder is connected with connecting cable. ^ EFFECT: increased radiation resistance. ^ 3 cl, 8 dwg