The Development Of Directional Gamma-ray Radiation Measuring Instrument

In recent years, uranium is an important resource for the development of nationaleconomy, so searching and measuring the uranium resource is vital. As Uranium isradioactive, it generates gamma rays when decaying. As long as detecting them outquickly by instruments, the uranium ore can be accurately found, at the same timeuranium content can be determined.The measurement of uranium ores is doing on the ore level of complicatedgeometry, so that the gamma rays of sample ores can not only be recorded, but alsothe gamma rays coming from the surrounding radioactive materials can be recorded toform the interference for measurements. So a directional gamma-ray radiationmeasuring instrument is needed, which can automatically eliminate the interferenceand accurately measure a certain direction’s gamma rays.In this subject, tested gamma rays and interference gamma rays get across aspecial probe to form two different signals on the rise time, main way signals anddeputy way signals. This kind of instrument screens and counts on them to determinesthe grade of uranium.The hardware and the software will be designed. The hardware design consists ofanalog circuits, digital circuits and power circuits. The role of the analog circuits isscreening the main and deputy way signals from the probe, and sending them to thesingle-chip microcomputer by the main and deputy way pulses, including theamplifying circuit, the pulse discriminator, the coincident circuit and the waveshapingcircuit of the main and deputy way pulses. As far as the pulse discriminator, twomethods will be designed, the zero discrimination and constant fraction discrimination.To compare them，circuits are improved. The digital circuits include a single-chipmicrocomputer and peripheral circuits. The power circuits have a charging circuit andthree kinds of voltage conversion circuits.The single-chip microcomputer program and PC program will be designed in thesoftware part. The former’s function is dealing with buttons, timing and constant measurements, saving and reading the measurement results, sending the data to thePC through a serial port. The PC program receives measurement data from themicrocontroller.This research can screen tested gamma rays and interference gamma rays,measure the grade of uranium ore and send the measurement data to the computer.