LaBr 3 spectrometry for environmental monitoring

The suitability of a LaBr3 detector for continuous environmental monitoring was tested. Spectra were acquired at 10 min intervals and then sent to a central database for further processing. The detector material has excellent properties, such as good energy resolution, high density and large-enough size. However, there are some serious drawbacks. The energy response is non-linear and the gain changes in a varying environment. A fitting algorithm, based on the La-138/K-40 multiplet at 1440 1470 keV, was developed to keep the gain stable. In addition, an enhanced version of the multiplet deconvolution code was made under Java programming language for the spectrum analysis. This code is able to cope with non-perfect energy calibration. The spectrometry system is an excellent add-on for a countrywide radiation monitoring network providing nuclide identification at an early stage of fall-out, albeit it cannot be adopted at all stations because of high costs.