Several parameters which could be used to describe the arrival time distribution of extensive air shower(EAS)particles have been discussed according to their relations with core distance and the fluctuations.Among the...Several parameters which could be used to describe the arrival time distribution of extensive air shower(EAS)particles have been discussed according to their relations with core distance and the fluctuations.Among these parameters,τis considered to be better than the others when applied to Linsley Effect.展开更多
As the nearest celestial body to the earth, the moon has become a hot spot again in astronomy field recently. The element analysis is a much important subject in many lunar projects. Remote X-ray spectrometry plays an...As the nearest celestial body to the earth, the moon has become a hot spot again in astronomy field recently. The element analysis is a much important subject in many lunar projects. Remote X-ray spectrometry plays an important role in the geochemical exploration of the solar bodies. Because of the quasi-vacuum atmosphere on the moon, which has no absorption of X-ray, the X-ray fluorescence analysis is an effective way to determine the elemental abundance of lunar surface. The CE-1 X-ray fluorescence spectrometer （CE-1/XFS） aims to map the major elemental compositions on the lunar surface. This paper describes a method for quantitative analysis of elemental compositions. A series of ground base experiments are done to examine the capability of XFS. The obtained results, which show a reasonable agreement with the certified values at a 30% uncertainty level for major elements, are presented.展开更多
The linac based XFEL and ERL are advanced （or, say, 4th generation） light sources, with different electron beam parameters and different advantages. However, the linac used for XFEL and ERL should provide very advan...The linac based XFEL and ERL are advanced （or, say, 4th generation） light sources, with different electron beam parameters and different advantages. However, the linac used for XFEL and ERL should provide very advanced beams with high energy, high peak and/or average current, very low emittance and low energy spread, thus making the linac very complicated and expensive. To share the XFEL and ERL advantages and save the construction-operation budget, a proposal of using a common superconducting electron linac for hard X-ray XFEL and ERL is described in this paper. The interactions between the XFEL and ERL beams via the accelerating structure are studied and the result is positive.展开更多
In a long-term planning for neutrino experiments in China, a medium baseline neutrino beam is proposed which uses a continue wave（CW） superconducting linac of 15 MW in beam power as the proton driver. The linac will...In a long-term planning for neutrino experiments in China, a medium baseline neutrino beam is proposed which uses a continue wave（CW） superconducting linac of 15 MW in beam power as the proton driver. The linac will be based on the technologies which are under development by the China-ADS project, namely it is also composed of a3.2 Me V normal conducting RFQ and five different types of superconducting cavities. However, the design philosophy is quite different from the China-ADS linac because of the much weaker requirement on reliability here. The nominal design energy and current are 1.5 Ge V and 10 m A, respectively. The general considerations and preliminary results on the physics design will be presented here. In addition, the alternative designs such as 2.0 Ge V and 2.5 Ge V, which may be required by the general design, can be easily extended from the nominal one.展开更多
文摘Several parameters which could be used to describe the arrival time distribution of extensive air shower(EAS)particles have been discussed according to their relations with core distance and the fluctuations.Among these parameters,τis considered to be better than the others when applied to Linsley Effect.
文摘As the nearest celestial body to the earth, the moon has become a hot spot again in astronomy field recently. The element analysis is a much important subject in many lunar projects. Remote X-ray spectrometry plays an important role in the geochemical exploration of the solar bodies. Because of the quasi-vacuum atmosphere on the moon, which has no absorption of X-ray, the X-ray fluorescence analysis is an effective way to determine the elemental abundance of lunar surface. The CE-1 X-ray fluorescence spectrometer （CE-1/XFS） aims to map the major elemental compositions on the lunar surface. This paper describes a method for quantitative analysis of elemental compositions. A series of ground base experiments are done to examine the capability of XFS. The obtained results, which show a reasonable agreement with the certified values at a 30% uncertainty level for major elements, are presented.
文摘The linac based XFEL and ERL are advanced （or, say, 4th generation） light sources, with different electron beam parameters and different advantages. However, the linac used for XFEL and ERL should provide very advanced beams with high energy, high peak and/or average current, very low emittance and low energy spread, thus making the linac very complicated and expensive. To share the XFEL and ERL advantages and save the construction-operation budget, a proposal of using a common superconducting electron linac for hard X-ray XFEL and ERL is described in this paper. The interactions between the XFEL and ERL beams via the accelerating structure are studied and the result is positive.
基金Supported by National Natural Science Foundation of China(11375122,91126003,11235012)
文摘In a long-term planning for neutrino experiments in China, a medium baseline neutrino beam is proposed which uses a continue wave（CW） superconducting linac of 15 MW in beam power as the proton driver. The linac will be based on the technologies which are under development by the China-ADS project, namely it is also composed of a3.2 Me V normal conducting RFQ and five different types of superconducting cavities. However, the design philosophy is quite different from the China-ADS linac because of the much weaker requirement on reliability here. The nominal design energy and current are 1.5 Ge V and 10 m A, respectively. The general considerations and preliminary results on the physics design will be presented here. In addition, the alternative designs such as 2.0 Ge V and 2.5 Ge V, which may be required by the general design, can be easily extended from the nominal one.
