A study on measurement of ionization radiation using a PN junction Si diode

For a detection of ionizing radiation using a small size PN junction Si diode, pre-amplifier design and system performance test were carried out. The pre-amplifier consists of charge sensitive operational-amplifier, clipping circuit, amplifier, and low-pass filter. Noise level and pulse amplitude created by ionizing radiation at the final output of the pre-amplifier were approximately 50mV and 200mV, respectively. and those electric signals showed the outstanding difference. As a performance test, linearity, energy dependence and relative average deviation were evaluated. The results showed that the linearity was within 2 percent and the relative energy dependence was 1.82 at the 54.2 keV and 1.23 at the 118 keV under the reference of 137Cs(662 keV). Also the relative average deviation was evaluated 2.7 percent in the maximum at the radiation dose rate(2 mR/h), but it showed decreasing trend as increasing radiation intensity