Evaluations Of Long-Life Nuclei Decay Data And Analysis Of Sum-Peak Effect

The thesis is divided into two parts. The first part contains the evaluation of nuclear decay data concluding 242Am, 242mAm, 130Sb and 93Sr. The application of nuclear technology usually takes a variety of nuclear data and nuclear decay data on the application of nuclear technology is among the essential. With the nuclear experiments and technology constantly updated, the measurement method of nuclear decay data has been significantly updated, ENSDF database radionuclide data is corresponding to update, so we have collected a large amount of literature data to evaluate some nuclear decay data for a new version. On the radioactive decay constant for further study of nuclear radioactive decay provides the power fro the technology and development of a variety of cross-disciplinary subjects. Current nuclear technology plays a very important role of the modern science, that maintains a strong vitality, not only in great scientific significance, but also in high-tech and cross-disciplinary research. This section describes the main nucleus of the general phenomenon of radioactive decay, the rules and basic theory. At the conclusion of the nuclear decay data and the basic method of calculation, the nuclear decay data evaluation that based nuclear decay (of the ENSDF database) is given. Here we collected 242Am, 242mAm, 130Sb and 93Sr four nuclear decay of experimental data in the 60 years, and re-evaluate the Q values, half-life, energy and relative intensity, intensity normalized factor, intensity and the absolute ofγ-ray. The nuclear half-life evaluation of 242Am is basically the same as previous evaluations, we put the various data of different Iβ-, Iεthat into the overall 100% decay. The accuracy of 242mAm's half-life has been increased , the new calculation of the energy data comes with a new value of 242mAm's Qαin 2003, so the energy recommended in this work is the latest.γ-ray energy of 242mAm'sαdecay is not updated in intensity measurements, and the value is the same as with the previous evaluation.The accuracy of 93Sr's half-life is higher than their predecessors because the previous evaluation calculates the weighted average from only two measuring results that are 1972He41 and 1986Ok03, this work calculates the weighted average from seven measuring results except 1974Gr29. We can get the relative intensity and the emission probability by calculating the Iβis close to zero, so the results of the evaluation and not the same as their predecessors.130Sb's half life in this work is calculated by weighted average of all data except 1962Ha16 as the uncertainty is less than their predecessors.The newest nuclear decay data of every nuclei is given, including Q-value, energy relative intensity and absolute intensity and normalization factor ofγ-ray, the nuclear decay figure is also re-drew.The second part contains the theoretical analysis and the experimental verification of the sum-peak effect. The Sum-peak effect is the twoγ-photon cascade may be absorbed by crystals in one decay time to form a true coincidence event, when the detector probably outputs pulses of not two separate, but equivalent to an energy of two photon absorption, which is called sum-peak effect. The intensity and spectrum measurements ofγ-ray(including x-ray) are important in detection of nuclear radiation. Measurement of nuclear level in excited state, study on decay class figure, determination of the short nuclear life, and experiment study of nuclear reactions all of these cannot be separated from the measurement of theγ-ray. In the radioactive analysis, analysis of radioactive ores, determination of the burn-up of reactor fuel, the flow analysis of certain fission products, as well as the analysis of the composition of pollutants in environmental protection are based on the composition ofγ-ray intensity and energy spectrum measurement. Besides, radioisotopes in industry, agriculture, medical and other nuclear technologies, are asked to measure theγ-ray intensity and energy. The detector is used to measure theγ-ray energy spectrum. There are three main ways in interaction with the material andγ-ray, which are photoelectric effect Compton effects and electron pair effect, the output spectrum is rather complex, full energy peaks, the compton plateau, single-escape peak (SE) and double-escape peak (DE), etc are formed in the energy spectrum. Also different detector media and different incident energy makes the peaks different, besides the three effects above there are other effects during the form of theγ-ray spectrum in the actual measurements, which makes theγ-ray spectrum more complex. The sum-peak effect is the one as we just said.In this part we introduce the basic theory of sum-peak effect first, then the NaI(Tl) detector is used to measure and analyze the sum-peak effect of the standard radiation source(60Co). the NaI(Tl) detector's crystal is a cylinder with the diameter 40mm and the height 40mm. the working voltage of the detector is 454V,60Co and 137Cs are used at the same time to make the energy calibration. The distance from the radiation to the detector are 0.2cm 0.5cm 1.0cm 1.5cm. finally four experimental data are analyzed to discuss the nature of sum-peak effect.