The half-life for 79Se decay is calculated by using the Logf1ut systematics method. Based on the data analysis and comparison with experimental data the 79Se half-life is recommended. The scheme for 79Se decay is also...The half-life for 79Se decay is calculated by using the Logf1ut systematics method. Based on the data analysis and comparison with experimental data the 79Se half-life is recommended. The scheme for 79Se decay is also shown and the radiation data are calculated in the text.展开更多
In order to carry out the measurement of heavy nuclei in accelerator mass spectrometry, characteristic X-rays of the incident projectile have been explored and used as a method for isobar discrimination. The projectil...In order to carry out the measurement of heavy nuclei in accelerator mass spectrometry, characteristic X-rays of the incident projectile have been explored and used as a method for isobar discrimination. The projectile X-ray combined with AMS technique has been set up in China institute of Atomic Energy. The measurement of 79Se was performed by resorting to the projectile X-ray AMS technique and the detection sensitivity of 79Se was improved more than 2 orders of magnitude. The detection limit was about 3.6x 10-9 for 79Se/Se.展开更多
The accelerator mass spectrometry（AMS） is an effective method for the determination of the half-life of long-lived radionuclides. In this paper, we report a method for measurement of the half-life of ^79Se. The numb...The accelerator mass spectrometry（AMS） is an effective method for the determination of the half-life of long-lived radionuclides. In this paper, we report a method for measurement of the half-life of ^79Se. The number of ^79Se atoms was determined from measured ^79Se/Se absolute ratios with the AMS system at the China Institute of Atomic Energy and the decay rate of ^79Se was determined by counting the emitted β-rays with a liquid scintillation spectrometer. The major improvements of our measurements include using the high abundance of an ^79Se sample which was cooled for many years to exclude the interference of short-lived nuclides, the extraction of SeO-2molecular ions, that results in a suppression of the ^79Br background by as much as about five orders of magnitude. Also, an AMS measurement of the absolute ratio of ^79Se/Se was developed to avoid systematic errors. The results show that ^79Se/Se is（2.35±0.12）×10^-7in the reference sample and the radioactivity of ^79Se is（1.24±0.05） Bq/g, so the half-life of ^79Se is（2.78±0.18）×10^5a.展开更多
So far accelerator mass spectrometry （AMS） technique has been used for the determination of numbers of important long-lived radioisotopes, such as <sup>10</sup>Be, <sup>14</sup>C, <sup>...So far accelerator mass spectrometry （AMS） technique has been used for the determination of numbers of important long-lived radioisotopes, such as <sup>10</sup>Be, <sup>14</sup>C, <sup>26</sup>Al, <sup>36</sup>Cl, <sup>41</sup>Ca and <sup>129</sup>I, in their applications of geoscienee, environmental science, archaeology and biomedical research. It is interesting to determine <sup>79</sup>Se with AMS technique for its potential application in biomedical research and environmental science presently. The published half-life values of <sup>79</sup>Se are more than 2 orders of magnitude apart, ranging from 10<sup>3</sup> to 10<sup>6</sup> a. The uncertainty of the half life has been an obstacle to the <sup>79</sup>Se application as a tracer. Selenium is one of the impor-展开更多
文摘The half-life for 79Se decay is calculated by using the Logf1ut systematics method. Based on the data analysis and comparison with experimental data the 79Se half-life is recommended. The scheme for 79Se decay is also shown and the radiation data are calculated in the text.
基金the Nation Natural Science Foundation of China China Nuclear Industry Corporation
文摘In order to carry out the measurement of heavy nuclei in accelerator mass spectrometry, characteristic X-rays of the incident projectile have been explored and used as a method for isobar discrimination. The projectile X-ray combined with AMS technique has been set up in China institute of Atomic Energy. The measurement of 79Se was performed by resorting to the projectile X-ray AMS technique and the detection sensitivity of 79Se was improved more than 2 orders of magnitude. The detection limit was about 3.6x 10-9 for 79Se/Se.
基金Supported by National Natural Science Foundation of China(11175266)
文摘The accelerator mass spectrometry（AMS） is an effective method for the determination of the half-life of long-lived radionuclides. In this paper, we report a method for measurement of the half-life of ^79Se. The number of ^79Se atoms was determined from measured ^79Se/Se absolute ratios with the AMS system at the China Institute of Atomic Energy and the decay rate of ^79Se was determined by counting the emitted β-rays with a liquid scintillation spectrometer. The major improvements of our measurements include using the high abundance of an ^79Se sample which was cooled for many years to exclude the interference of short-lived nuclides, the extraction of SeO-2molecular ions, that results in a suppression of the ^79Br background by as much as about five orders of magnitude. Also, an AMS measurement of the absolute ratio of ^79Se/Se was developed to avoid systematic errors. The results show that ^79Se/Se is（2.35±0.12）×10^-7in the reference sample and the radioactivity of ^79Se is（1.24±0.05） Bq/g, so the half-life of ^79Se is（2.78±0.18）×10^5a.
文摘So far accelerator mass spectrometry （AMS） technique has been used for the determination of numbers of important long-lived radioisotopes, such as <sup>10</sup>Be, <sup>14</sup>C, <sup>26</sup>Al, <sup>36</sup>Cl, <sup>41</sup>Ca and <sup>129</sup>I, in their applications of geoscienee, environmental science, archaeology and biomedical research. It is interesting to determine <sup>79</sup>Se with AMS technique for its potential application in biomedical research and environmental science presently. The published half-life values of <sup>79</sup>Se are more than 2 orders of magnitude apart, ranging from 10<sup>3</sup> to 10<sup>6</sup> a. The uncertainty of the half life has been an obstacle to the <sup>79</sup>Se application as a tracer. Selenium is one of the impor-
