Remeasurement of the half-life of ^(79)Se has been carried out with the projectile x-ray detection(PXD)in accelerator mass spectrometry.We made two major improvements over our earlier ^(79)Se half-life determination[N...Remeasurement of the half-life of ^(79)Se has been carried out with the projectile x-ray detection(PXD)in accelerator mass spectrometry.We made two major improvements over our earlier ^(79)Se half-life determination[Nucl.Instrum.Methods B 123(1997)403].Fristly,the PXD technique has been used for separation of ^(79)Se and 75Se from 79Br and 75As isobars respectively.Secondly,the half-life of ^(79)Se has been measured relative to the known precise half-life of ^(75)Se(119.79±0.04d).A more reliable half-life of ^(79)Se measured with the PXD technique is(2.95±0.38)×10^(5)y,about a factor of one lower than the previous value,1.1 × 10^(6)y.The problems in the previous measurement are discussed.展开更多
Conventional nuclear fusion occurs in plasma at temperatures greater than 10^(7)℃ or when energy higher than 10 keV is applied.We report a new result of anomalous neutron emission,also called cascade neutron burst em...Conventional nuclear fusion occurs in plasma at temperatures greater than 10^(7)℃ or when energy higher than 10 keV is applied.We report a new result of anomalous neutron emission,also called cascade neutron burst emission,from deuterium-loaded titanium and uranium deuteride samples at room temperature.The number of neutrons in the large bursts is measured as up to 2800 in less than a 64-μs interval.We suggest that the anomalous cascade neutron bursts are correlated with deuterium-loaded metals and probably the result of nuclear reactions occurring in the samples.展开更多
Anomalous ^(3)He/^(4)He ratios in deuterium-loaded titanium samples are observed to be about 1-4×10^(-1),much greater than the values (≤10^(-4)) in natural objects.Control experiments with the deuterium-unloaded...Anomalous ^(3)He/^(4)He ratios in deuterium-loaded titanium samples are observed to be about 1-4×10^(-1),much greater than the values (≤10^(-4)) in natural objects.Control experiments with the deuterium-unloaded titanium sample and original industrial deuterium gas are also carried out,but no anomalous 3He/4He values are observed.In addition,anomalous tritium in deuterium-loaded titanium samples are also observed.To explain the excess 3He and tritium in the deuterium-loaded titanium samples,it is required that the deuteron-induced nuclear reaction occurs in the samples at low temperature.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
基金Supported in part by the Nuclear Energy Foundation of China,No.H7010101.
文摘Remeasurement of the half-life of ^(79)Se has been carried out with the projectile x-ray detection(PXD)in accelerator mass spectrometry.We made two major improvements over our earlier ^(79)Se half-life determination[Nucl.Instrum.Methods B 123(1997)403].Fristly,the PXD technique has been used for separation of ^(79)Se and 75Se from 79Br and 75As isobars respectively.Secondly,the half-life of ^(79)Se has been measured relative to the known precise half-life of ^(75)Se(119.79±0.04d).A more reliable half-life of ^(79)Se measured with the PXD technique is(2.95±0.38)×10^(5)y,about a factor of one lower than the previous value,1.1 × 10^(6)y.The problems in the previous measurement are discussed.
基金Supported by the President Foundation of the China Institute of Atomic Energy(No YZ-0704).
文摘Conventional nuclear fusion occurs in plasma at temperatures greater than 10^(7)℃ or when energy higher than 10 keV is applied.We report a new result of anomalous neutron emission,also called cascade neutron burst emission,from deuterium-loaded titanium and uranium deuteride samples at room temperature.The number of neutrons in the large bursts is measured as up to 2800 in less than a 64-μs interval.We suggest that the anomalous cascade neutron bursts are correlated with deuterium-loaded metals and probably the result of nuclear reactions occurring in the samples.
基金Supported by President Foundation of the China Institute of Atomic Energy(No YZ-0704).
文摘Anomalous ^(3)He/^(4)He ratios in deuterium-loaded titanium samples are observed to be about 1-4×10^(-1),much greater than the values (≤10^(-4)) in natural objects.Control experiments with the deuterium-unloaded titanium sample and original industrial deuterium gas are also carried out,but no anomalous 3He/4He values are observed.In addition,anomalous tritium in deuterium-loaded titanium samples are also observed.To explain the excess 3He and tritium in the deuterium-loaded titanium samples,it is required that the deuteron-induced nuclear reaction occurs in the samples at low temperature.
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.
