In addition to the magnetic confinement fusion plasma,Thomson scattering has been applied to measure electron density and temperature of low-temperature plasmas.Based on a linear magnetized plasma device,a set of Thom...In addition to the magnetic confinement fusion plasma,Thomson scattering has been applied to measure electron density and temperature of low-temperature plasmas.Based on a linear magnetized plasma device,a set of Thomson scattering diagnostic system is designed to diagnose the plasma with n_(e)=10^(18)–10^(19)m^(-3)and T_(e)=2–5eV.Due to low plasma temperature and density,this diagnostic system needs high spectral resolution and collection efficiency to meet the requirements of electron velocity distribution function measurements.Through the bench test,it is confirmed that the spectral resolution reaches 0.01 nm,and theoretical collection efficiency is high enough to obtain a Thomson scattering spectrum by 1000 accumulations.展开更多
Motivated by the need of the electron density measurement for the Keda Reconnection eXperiment(KRX)facility which is under development,an interferometer system has been designed and tested in bench.The 320 GHz solid-s...Motivated by the need of the electron density measurement for the Keda Reconnection eXperiment(KRX)facility which is under development,an interferometer system has been designed and tested in bench.The 320 GHz solid-state microwave source with 1 mm wavelength is used to fulfill the high phase difference measurement in such low temperature plasma device.The results of the bench test show that the phase difference is accurately measured.In contrast to tens of degrees of phase shift expected to be measured on the KRX,the system noise(~1°)is low enough for the KRX diagnostics.In order to optimize the system for better performance,we utilize the Terasense sub-THz imaging system to adjust alignment.The interferometer system has also been calibrated via changing of the optical path length controlled by the piezo inertial motor.Simultaneously,high density polyethylene thin film is introduced successfully to change a tiny phase difference and test the sensitivity of the interferometer system.展开更多
Recent experiments have observed magnetic reconnection in laser-produced high-energy-density(HED)plasma bubbles.We perform two-dimensional(2-D)particle-in-cell(PIC)simulations to investigate magnetic reconnection betw...Recent experiments have observed magnetic reconnection in laser-produced high-energy-density(HED)plasma bubbles.We perform two-dimensional(2-D)particle-in-cell(PIC)simulations to investigate magnetic reconnection between two approaching HED plasma bubbles.It is found that the expanding velocity of the bubbles has a great influence on the process of magnetic reconnection.When the expanding velocity is small,a single X line reconnection is formed.However,when the expanding velocity is sufficiently large,we can observe a plasmoid in the vicinity of the X line.At the same time,the structures of the electromagnetic field in HED plasma reconnection are similar to that in Harris current sheet reconnection.展开更多
文摘In addition to the magnetic confinement fusion plasma,Thomson scattering has been applied to measure electron density and temperature of low-temperature plasmas.Based on a linear magnetized plasma device,a set of Thomson scattering diagnostic system is designed to diagnose the plasma with n_(e)=10^(18)–10^(19)m^(-3)and T_(e)=2–5eV.Due to low plasma temperature and density,this diagnostic system needs high spectral resolution and collection efficiency to meet the requirements of electron velocity distribution function measurements.Through the bench test,it is confirmed that the spectral resolution reaches 0.01 nm,and theoretical collection efficiency is high enough to obtain a Thomson scattering spectrum by 1000 accumulations.
基金National Natural Science Foundation of China(No.11975231)。
文摘Motivated by the need of the electron density measurement for the Keda Reconnection eXperiment(KRX)facility which is under development,an interferometer system has been designed and tested in bench.The 320 GHz solid-state microwave source with 1 mm wavelength is used to fulfill the high phase difference measurement in such low temperature plasma device.The results of the bench test show that the phase difference is accurately measured.In contrast to tens of degrees of phase shift expected to be measured on the KRX,the system noise(~1°)is low enough for the KRX diagnostics.In order to optimize the system for better performance,we utilize the Terasense sub-THz imaging system to adjust alignment.The interferometer system has also been calibrated via changing of the optical path length controlled by the piezo inertial motor.Simultaneously,high density polyethylene thin film is introduced successfully to change a tiny phase difference and test the sensitivity of the interferometer system.
基金the National Natural Science Foundation of China under Grant Nos 11220101002,41174124,41274144 and 41121003the Key Research Program of Chinese Academy of Sciences(KZZD-EW-01)+1 种基金the National Basic Research Program of China(2012CB825602)the Ocean Public Welfare Scientific Research Project,State Oceanic Administration of China(No 201005017).
文摘Recent experiments have observed magnetic reconnection in laser-produced high-energy-density(HED)plasma bubbles.We perform two-dimensional(2-D)particle-in-cell(PIC)simulations to investigate magnetic reconnection between two approaching HED plasma bubbles.It is found that the expanding velocity of the bubbles has a great influence on the process of magnetic reconnection.When the expanding velocity is small,a single X line reconnection is formed.However,when the expanding velocity is sufficiently large,we can observe a plasmoid in the vicinity of the X line.At the same time,the structures of the electromagnetic field in HED plasma reconnection are similar to that in Harris current sheet reconnection.
