In this paper,the momentum conservation equation in the longitudinal direction for simple railgun was deduced.Then,a three-dimensional model was established and the finite element method was utilized to simulate the p...In this paper,the momentum conservation equation in the longitudinal direction for simple railgun was deduced.Then,a three-dimensional model was established and the finite element method was utilized to simulate the problem.Based on the simulation,some results such as the surface force on the electromagnetic field,the electromagnetic force on the conductor in the longitudinal direction were obtained.Besides,the surface force density on different longitudinal section of railgun was analyzed and discussed in details.The results showed that the momentum of the railgun system was conserved when the surface force of the electromagnetic field was contained.Moreover,large amount of longitudinal force was transmitted to the breech by the electromagnetic field in the form of surface force.The exact position and distribution of recoil were related to the current input device.展开更多
The Doppler effect is a phenomenon of intrinsic kinematic character. This paper analyzes the kinematic Doppler effect for the case where the source is moving and the observer is at rest in the classical limit. The par...The Doppler effect is a phenomenon of intrinsic kinematic character. This paper analyzes the kinematic Doppler effect for the case where the source is moving and the observer is at rest in the classical limit. The particle nature properties of radiation are considered and how it affects the dynamics of the Source has been studied. The dynamical and kinematical equations have been derived by considering this effect. It has been conclusively shown that a moving light-emitting source experiences a finite recoil momentum in the direction opposite to the direction of motion and come to rest in finite time.展开更多
The relative partial cross sections for ^13C^6＋ -Ar collisions at 4.15-11.08 ke V/u incident energy are measured. The cross-section ratios σ^2E/σ^SC, σ^3E/σ^SC, σ^4E/σ^SC and σ^SE/σ^SC are approximately the c...The relative partial cross sections for ^13C^6＋ -Ar collisions at 4.15-11.08 ke V/u incident energy are measured. The cross-section ratios σ^2E/σ^SC, σ^3E/σ^SC, σ^4E/σ^SC and σ^SE/σ^SC are approximately the constants of 0.514-0.05, 0.204-0.03, 0.064-0.03 and 0.024-0.01 in this region. The significance of the multi-electron process in highly charged ions （HCIs） with argon collisions is demonstrated （σ^ME/σ^SC as high as 0.794-0.06）. In multi-electron processes, it is shown that transfer ionization is dominant while pure electron capture is weak and negligible. For all reaction channels, the cross-sections are independent of the incident energy in the present energy region, which is in agreement with the static characteristic of classic models, i.e. the molecular Coulomb over-the-barrier model （MCBM）, the extended classical over-the-barrier model （ECBM） and the semiempirical scaling laws （SL）. The result is compared with these classical models and with our previous work of ^13C^6＋ -Ne collisions [Chin. Phys. Lett. 23 （2006） 95].展开更多
The principle and technique details of recoil ion momentum imaging are discussed and summarized. The recoil ion momentum spectroscopy built at the Institute of Modern Physics (Lanzhou) is presented. The first results ...The principle and technique details of recoil ion momentum imaging are discussed and summarized. The recoil ion momentum spectroscopy built at the Institute of Modern Physics (Lanzhou) is presented. The first results obtained at the setup are analyzed. For 30 keV He2+ on He collision, it is found that the capture of single electron occurs dominantly into the first excited states, and the related scattering angle results show that the ground state capture occurs at large impact parameters, while the capture into excited states occurs at small impact parameters. The results manifest the collision dynamics for the sub-femto-second process can be studied through the techniques uniquely. Finally, the future possibilities of applications of the recoil ion momentum spectroscopy in other fields are outlined.展开更多
文摘In this paper,the momentum conservation equation in the longitudinal direction for simple railgun was deduced.Then,a three-dimensional model was established and the finite element method was utilized to simulate the problem.Based on the simulation,some results such as the surface force on the electromagnetic field,the electromagnetic force on the conductor in the longitudinal direction were obtained.Besides,the surface force density on different longitudinal section of railgun was analyzed and discussed in details.The results showed that the momentum of the railgun system was conserved when the surface force of the electromagnetic field was contained.Moreover,large amount of longitudinal force was transmitted to the breech by the electromagnetic field in the form of surface force.The exact position and distribution of recoil were related to the current input device.
文摘The Doppler effect is a phenomenon of intrinsic kinematic character. This paper analyzes the kinematic Doppler effect for the case where the source is moving and the observer is at rest in the classical limit. The particle nature properties of radiation are considered and how it affects the dynamics of the Source has been studied. The dynamical and kinematical equations have been derived by considering this effect. It has been conclusively shown that a moving light-emitting source experiences a finite recoil momentum in the direction opposite to the direction of motion and come to rest in finite time.
基金Supported by the National Natural Science Foundation of China under Grant No 10434100. The experiment would not be finished without the help of the ECR team. The authors would like to thank Professor Jianguo Wang and Professor Burhard Fricke for many helpful discussions.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10304019,10134010 and 10375080.
文摘The relative partial cross sections for ^13C^6＋ -Ar collisions at 4.15-11.08 ke V/u incident energy are measured. The cross-section ratios σ^2E/σ^SC, σ^3E/σ^SC, σ^4E/σ^SC and σ^SE/σ^SC are approximately the constants of 0.514-0.05, 0.204-0.03, 0.064-0.03 and 0.024-0.01 in this region. The significance of the multi-electron process in highly charged ions （HCIs） with argon collisions is demonstrated （σ^ME/σ^SC as high as 0.794-0.06）. In multi-electron processes, it is shown that transfer ionization is dominant while pure electron capture is weak and negligible. For all reaction channels, the cross-sections are independent of the incident energy in the present energy region, which is in agreement with the static characteristic of classic models, i.e. the molecular Coulomb over-the-barrier model （MCBM）, the extended classical over-the-barrier model （ECBM） and the semiempirical scaling laws （SL）. The result is compared with these classical models and with our previous work of ^13C^6＋ -Ne collisions [Chin. Phys. Lett. 23 （2006） 95].
基金the National Natural Science Foundation of China (Grant No. 10434100)
文摘The principle and technique details of recoil ion momentum imaging are discussed and summarized. The recoil ion momentum spectroscopy built at the Institute of Modern Physics (Lanzhou) is presented. The first results obtained at the setup are analyzed. For 30 keV He2+ on He collision, it is found that the capture of single electron occurs dominantly into the first excited states, and the related scattering angle results show that the ground state capture occurs at large impact parameters, while the capture into excited states occurs at small impact parameters. The results manifest the collision dynamics for the sub-femto-second process can be studied through the techniques uniquely. Finally, the future possibilities of applications of the recoil ion momentum spectroscopy in other fields are outlined.
