Beam emittance plays an important role in any accelerator, and it is a main parameter to judge the performance of an accelerator. Emittance optimization is an indispensable part in conditioning and operation of the fa...Beam emittance plays an important role in any accelerator, and it is a main parameter to judge the performance of an accelerator. Emittance optimization is an indispensable part in conditioning and operation of the facility. For a laser-driven high brightness injector, different time structure of the laser pulse has different effects on transverse emittance. In order to compare Gaussian and flat-top laser pulse, systematic simulations of 500 pC have been done. From the simulation results, one can see that flat-top pulse laser will yield smaller minimal transverse beam size and transverse beam emittance than Gaussian pulse laser.展开更多
We calculate the HBT radius R_(S) for π^(+)with Coulomb interaction using the string melting version of a multiphase transport(AMPT)model.We study the relationship between the single-particle space-momentum angle and...We calculate the HBT radius R_(S) for π^(+)with Coulomb interaction using the string melting version of a multiphase transport(AMPT)model.We study the relationship between the single-particle space-momentum angle and the particle sources and discuss HBT radii without single-particle space-momentum correlation.Additionally,we study the Coulomb interaction effect on the numerical connection between the single-particle space-momentum angle distribution and the transverse momentum dependence of R_(S).展开更多
We analyze the transverse momentum dependence of HBT radii in relativistic heavy-ion collisions using several source models.Results indicate that the single-particle space-momentum angle distribution plays an importan...We analyze the transverse momentum dependence of HBT radii in relativistic heavy-ion collisions using several source models.Results indicate that the single-particle space-momentum angle distribution plays an important role in the transverse momentum dependence of HBT radii.In a cylinder source,we use several formulas to describe the transverse momentum dependence of HBT radii and the single-particle space-momentum angle distribution.We also make a numerical connection between them in the transverse plane.展开更多
Using the string melting version of a multiphase transport(AMPT)model,we analyze the transverse momentum dependence of the HBT radius R_(s) and the single-pion angle distribution on the transverse plane in central Au+...Using the string melting version of a multiphase transport(AMPT)model,we analyze the transverse momentum dependence of the HBT radius R_(s) and the single-pion angle distribution on the transverse plane in central Au+Au collisions at■,and 200 GeV.Additionally,a numerical connection between these two phenomena is established with a series of functions.We can estimate the single-pion angle distribution on the transverse plane from HBT analysis.展开更多
A method based on newly presented state space formulations is developed for analyzing the bending, vibration and stability of laminated transversely isotropic rectangular plates with simply supported edges. By introdu...A method based on newly presented state space formulations is developed for analyzing the bending, vibration and stability of laminated transversely isotropic rectangular plates with simply supported edges. By introducing two displacement functions and two stress functions, two independent state equations were constructed based on the three_dimensional elasticity equations for transverse isotropy. The original differential equations are thus decoupled with the order reduced that will facilitate obtaining solutions of various problems. For the simply supported rectangular plate, two relations between the state variables at the top and bottom surfaces were established. In particular, for the free vibration (stability) problem, it is found that there exist two independent classes: One corresponds to the pure in_plane vibration (stability) and the other to the general bending vibration (stability). Numerical examples are finally presented and the effects of some parameters are discussed.展开更多
The term “relativistic mass” defined by equation m=γm<sub>0</sub> with γ=(1-v<sup>2</sup>/c<sup>2</sup>)<sup>-1/2</sup> has a somewhat controversial history, based o...The term “relativistic mass” defined by equation m=γm<sub>0</sub> with γ=(1-v<sup>2</sup>/c<sup>2</sup>)<sup>-1/2</sup> has a somewhat controversial history, based on special relativity theory, mathematics, logic, intuition, experiment, and ontology. Key is the ontological framework, specifically whether the framework does or does not include gravity. This paper examines both cases, with detailed analysis of gravitomagnetism and of relativistic mass in collisions.展开更多
基金supported by China Scholarship Council (Grant No. 2009634063)the National Natural Science Foundation of China (Grant No. 10875117)the National "985" Project (Grant No. 173123200402002)
文摘Beam emittance plays an important role in any accelerator, and it is a main parameter to judge the performance of an accelerator. Emittance optimization is an indispensable part in conditioning and operation of the facility. For a laser-driven high brightness injector, different time structure of the laser pulse has different effects on transverse emittance. In order to compare Gaussian and flat-top laser pulse, systematic simulations of 500 pC have been done. From the simulation results, one can see that flat-top pulse laser will yield smaller minimal transverse beam size and transverse beam emittance than Gaussian pulse laser.
文摘We calculate the HBT radius R_(S) for π^(+)with Coulomb interaction using the string melting version of a multiphase transport(AMPT)model.We study the relationship between the single-particle space-momentum angle and the particle sources and discuss HBT radii without single-particle space-momentum correlation.Additionally,we study the Coulomb interaction effect on the numerical connection between the single-particle space-momentum angle distribution and the transverse momentum dependence of R_(S).
文摘We analyze the transverse momentum dependence of HBT radii in relativistic heavy-ion collisions using several source models.Results indicate that the single-particle space-momentum angle distribution plays an important role in the transverse momentum dependence of HBT radii.In a cylinder source,we use several formulas to describe the transverse momentum dependence of HBT radii and the single-particle space-momentum angle distribution.We also make a numerical connection between them in the transverse plane.
文摘Using the string melting version of a multiphase transport(AMPT)model,we analyze the transverse momentum dependence of the HBT radius R_(s) and the single-pion angle distribution on the transverse plane in central Au+Au collisions at■,and 200 GeV.Additionally,a numerical connection between these two phenomena is established with a series of functions.We can estimate the single-pion angle distribution on the transverse plane from HBT analysis.
文摘A method based on newly presented state space formulations is developed for analyzing the bending, vibration and stability of laminated transversely isotropic rectangular plates with simply supported edges. By introducing two displacement functions and two stress functions, two independent state equations were constructed based on the three_dimensional elasticity equations for transverse isotropy. The original differential equations are thus decoupled with the order reduced that will facilitate obtaining solutions of various problems. For the simply supported rectangular plate, two relations between the state variables at the top and bottom surfaces were established. In particular, for the free vibration (stability) problem, it is found that there exist two independent classes: One corresponds to the pure in_plane vibration (stability) and the other to the general bending vibration (stability). Numerical examples are finally presented and the effects of some parameters are discussed.
文摘The term “relativistic mass” defined by equation m=γm<sub>0</sub> with γ=(1-v<sup>2</sup>/c<sup>2</sup>)<sup>-1/2</sup> has a somewhat controversial history, based on special relativity theory, mathematics, logic, intuition, experiment, and ontology. Key is the ontological framework, specifically whether the framework does or does not include gravity. This paper examines both cases, with detailed analysis of gravitomagnetism and of relativistic mass in collisions.
