Design of a radiation counter and the measurements in various radiation media

In this thesis, On inexpensive and portable radiation counter is designed by using Siemens' s BPW-34 silicon PIN photodiode as radiation detector and radiation measurements in various radiation media are taken. The counter consists of detector and electronic units. Detector probe is made of three parallely connected BPW-34 photodiodes to increase the sensitivity of the counter system. Thomson's LF 357 and RCAxs CA 3130 operational amplifiers in analogue circuit units and general purpose digital integrated circuits in digital units are used. Electrical calibrations has been carried out and radiation tests are made on the counter system. From the results of these tests the dead time and noise level at the discriminator input are measure as 30 |ls and 40 mV respectively. The radiation tests are also as following; for P- particles of 0,535 MeV are 0,170 ops/ mrad/h, for gamma rays of 1,25 MeV are 2,53 cps/ mR/h. But no sensitivity measurement were observed for a-particles. Key Words : Radiation detection, PIN structure, sensitive area, depletion layer, analogue circuits, digital circuits, dead time, noise pulses.