The Development Of Gamma Dose Rate Instrument Based On The Pectrum Correction

With nuclear technology widely used in various fields of the national economy,nuclear radiation to the environment and human health is also more and more attentionfrom the public, radiation protection technology research is becoming more and moreimportant, especially after the Japanese nuclear power station accident.As the biological effects of radiation, radiation dose determines the size of theenvironment and human impact, the corresponding, the intensity of radiation dose ratemeasurements--becomes particularly important, only developed accurate dose rateinstrument can meet the measurement needs.At present, there has been a large number of different models of dose rate meter onthe market,the probe and the measuring principle are different. basically usingscintillation detector and gas detector as the dose rate meter probe At home and abroad,in order to improve the portability of the instrument, the semiconductor detector is alsoused as a probe. The majority of portable dose rate meter basically use the countmethod, and use additional compensation method to obtain the measurement resultsafter scaled, even so the error is great, for all of the dosimeter exist the problem ofenergy response.In the light of the problem of energy response. put forward a method thataccording to the spectrum to correct dose measurement in this paper, and developed anew dose rate meter combined with electronic and computer technology, which use adigital spectrum acquisition system based on the FPGA could accelerate the systemacquisition ability; and the spectrum data is transmitted to the VC platform based onspectrum data processing system, through the C8051MCU and the built-in USB;finally uses the software correction method to improve the energy response. In addition,studied the energy spectrum dose correction method, using gamma spectrum of point source to calibration factor,but due to limited experimental conditions, measuredspectrum of137Cs and60Co,accessed to the low-energy filtration spectrum of X-raymachine, after getting as many standard γ spectrum and standard dose rate measured byhigh-precision ionization chamber, use the spectrum-dose transform method tocompute the factors. The instrument can automatically accomplish spectrum to the doserate conversion after scaled, Comparing with ionization chamber measuring results, therelative error is small, so the method is feasible.