Analysis of energy-peaks characteristic in NaI(Tl) spectrometer for radionuclide identification in environmental radiation monitoring device

The development of nuclear facilities has been emerging rapidly in this century, it's causing the development of technology which concerns the quality of the environment is a must. Because this condition is related to the polluted nuclear radiation in the environment, especially in urban, and nuclear facilities. This causes an environmental radiation monitoring device is needed to determine abnormalities. Currently, the environmental radiation monitoring devices in the station only could monitors gross gamma radiation. The device cannot distinguish whether the increase in dose rate is due to abnormal events, or due to natural radiation. Therefore, we need a device that can have the ability of spectroscopy, thus it can distinguish the radionuclide source that causes an increase in the dose rate like NaI(Tl) gamma spectrometer. The device has been configured using a NaI(Tl) detector with a peak characteristic observation method with various conditions of acquisition time and dose rate. This was tested in laboratories using Cs-137 as a sample. Tests have been done by varying the value of time and dose rate when measure. Time used varies, 1 minute, 5 minutes, 10 minutes, 30 minutes, 60 minutes, 90 minutes and 120 minutes with a varying dose rate of 0.1479, 0.1115, 0.0956 and 0.0802 |aSv/h. Data has been analyzed using the high summing ratio method to be able to distinguish measurement values using sample and background measurements. The result shows that the detector has stable when measuring for 30 minutes with FWHM value 60, and the dose rate is not less than 0.0802 |aSv/h, and it was able to distinguish background and source value from 1 -minute acquisition using a high summing ratio method.