On the basis of general description of AMS, the advantage and development of tandem accelerator based AMS are discussed. The AMS facility at Peking University and its preliminary applications are described.
Based on the generalized truncated second-order moments,an approximate analytical formula of the beam propagation factor M^2 of high-power laser beams passing through the optical system with multiple hard-edged apertu...Based on the generalized truncated second-order moments,an approximate analytical formula of the beam propagation factor M^2 of high-power laser beams passing through the optical system with multiple hard-edged apertures is deduced.Numerical examples of the beams passing through an aperture-spatial filter are enclosed,and the influences of amplitude modulations(AMs)and phase fluctuations(PFs)on the beam propagation quality of high-power laser beams passing through the multi-apertured ABCD optical system are considered and discussed.It is shown that PFs are able to degrade the beam propagation quality of laser beams more than AMs when the high-power laser beams passing through the aperture-spatial filter,furthermore,one or two aperture-lens optical systems configured appropriate aperture parameters are both able to upgrade the beam propagation quality of high-power laser beams.The M2 factor of Gaussian beam passing through the multi-aperture optical system is a special case in this paper.展开更多
A study on the anthropogenic 129I in the environments around the high radioactivity sites has been carried out. The samples were collected from the surface waters and ground waters. 129I contents in the samples were m...A study on the anthropogenic 129I in the environments around the high radioactivity sites has been carried out. The samples were collected from the surface waters and ground waters. 129I contents in the samples were measured using the AMS system at the China Institute of Atomic Energy. The 129I contents in The measured samples around the high radioactivity sites range from 108 atoms/l to 109 atoms/l. The result shows that 129I contents in the water samples collected in the vicinity of high radio-activity sites is many orders of magnitude higher than the content in the original rain water. 129I may be used as an environment monitor around the nuclear sites.展开更多
文摘On the basis of general description of AMS, the advantage and development of tandem accelerator based AMS are discussed. The AMS facility at Peking University and its preliminary applications are described.
基金Science Fund from the Shaanxi Provincial Education Department,China(Grant No.18JK0723).
文摘Based on the generalized truncated second-order moments,an approximate analytical formula of the beam propagation factor M^2 of high-power laser beams passing through the optical system with multiple hard-edged apertures is deduced.Numerical examples of the beams passing through an aperture-spatial filter are enclosed,and the influences of amplitude modulations(AMs)and phase fluctuations(PFs)on the beam propagation quality of high-power laser beams passing through the multi-apertured ABCD optical system are considered and discussed.It is shown that PFs are able to degrade the beam propagation quality of laser beams more than AMs when the high-power laser beams passing through the aperture-spatial filter,furthermore,one or two aperture-lens optical systems configured appropriate aperture parameters are both able to upgrade the beam propagation quality of high-power laser beams.The M2 factor of Gaussian beam passing through the multi-aperture optical system is a special case in this paper.
文摘A study on the anthropogenic 129I in the environments around the high radioactivity sites has been carried out. The samples were collected from the surface waters and ground waters. 129I contents in the samples were measured using the AMS system at the China Institute of Atomic Energy. The 129I contents in The measured samples around the high radioactivity sites range from 108 atoms/l to 109 atoms/l. The result shows that 129I contents in the water samples collected in the vicinity of high radio-activity sites is many orders of magnitude higher than the content in the original rain water. 129I may be used as an environment monitor around the nuclear sites.
