Only a small amount of spectral information is collected because the collection solid angle of the optical fiber probe and lens is very limited when collecting spectral information.To overcome this limitation,this stu...Only a small amount of spectral information is collected because the collection solid angle of the optical fiber probe and lens is very limited when collecting spectral information.To overcome this limitation,this study presents a novel method for acquiring plasma spectral information from various spatial directions.A parabolic-shaped plasma spectral collection device(PSCD)is employed to effectively collect more spectral information into the spectrometer,thereby enhancing the overall spectral intensity.The research objects in this study were soil samples containing different concentrations of heavy metals Pb,Cr,and Cd.The results indicate that the PSCD significantly enhances the spectral signal,with an enhancement rate of up to 45%.Moreover,the signal-to-noise ratio also increases by as much as 36%.Simultaneously,when compared to the absence of a device,it is found that there is no significant variation in plasma temperature when the PSCD is utilized.This observation eliminates the impact of the spatial effect caused by the PSCD on the spectral intensity.Consequently,a concentrationspectral intensity relationship curve is established under the PSCD.The results revealed that the linear fitting R^(2)for Pb,Cr,and Cd increased by 0.011,0.001,and 0.054,respectively.Additionally,the limit of detection(LOD)decreased by 0.361 ppm,0.901 ppm,and 0.602 ppm,respectively.These findings indicate that the spectral enhancement rate elevates with the increase in heavy metal concentration.Hence,the PSCD can effectively enhance the spectral intensity and reduce the detection limit of heavy metals in soil.展开更多
In order to investigate electron dynamics near the electron diffusion region in mag- netic reconnection process, an upgrade in the linear magnetized plasma (LMP) device is accom- plished at the University of Science...In order to investigate electron dynamics near the electron diffusion region in mag- netic reconnection process, an upgrade in the linear magnetized plasma (LMP) device is accom- plished at the University of Science and Technology of China. Radio frequency (RF) helicon discharge is used to generate a quasi-stationary plasma, and a time-dependent magnetic field is applied to the plasma, which exhibits an X-type neutral point in vacuum. A two-dimensional sophisticated mobile platform is built up, providing a high spatial resolution, below 0.5 ram, for the diagnostics.展开更多
Aluminum alloy 2024 has been implanted with nitrogen ions at various doses by plasma based ion implantation. The introduction of energetic ions causes structural change within the near surface region of the solid. The...Aluminum alloy 2024 has been implanted with nitrogen ions at various doses by plasma based ion implantation. The introduction of energetic ions causes structural change within the near surface region of the solid. The samples have been characterized by X-ray Photoelectron Spectroscopy at various depths. The chemical states of Al and N were identified by deconvolution of the recorded XPS spectra. After plasma based ion implanted nitrogen into aluminum, not only the AlN precipitates but also super saturated solution of nitrogen forms. The presence of aluminum in different chemical states is corresponding to Al, AlN and Al2O3. The majority of nitrogen is in the form of the supersaturated solution. With the increase of nitrogen dose, the amount of AlN precipitates increases.展开更多
The multi-radiation of X-rays was investigated with special attention to their energy spectrum in a Mather-type plasma focus device (operated with argon gas). The analysis is based on the effect of anomalous resista...The multi-radiation of X-rays was investigated with special attention to their energy spectrum in a Mather-type plasma focus device (operated with argon gas). The analysis is based on the effect of anomalous resistances. To study the energy spectrum, a four-channel diode X-ray spectrometer was used along with a special set of filters. The filters were suitable for detection of medium range X-rays as well as hard X-rays with energy exceeding 30 keV. The results indicate that the anomalous resistivity effect during the post pinch phase may cause multi-radiation of X-rays with a total duration of 300 ± 50 ns. The significant contribution of Cu-Kα was due to the medium range X-rays, nonetheless, hard X-rays with energies greater than 15 keV also participate in the process. The total emitted X-ray energy in the forms of Cu-K and Cu-K/3 was around 0.14 ± 0.02 (J/Sr) and 0.04 ±0.01 (J/Sr), respectively. The total energy of the emitted hard X-ray (〉 15 keV) was around 0.12± 0.02 (J/Sr).展开更多
A new compact cascaded arc device for plasma-wall interaction study is developed at the Institute of Plasma Physics,Chinese Academy of Sciences.A magnetic field up to 0.8 T is achieved to confine plasmas in a 1.2 m lo...A new compact cascaded arc device for plasma-wall interaction study is developed at the Institute of Plasma Physics,Chinese Academy of Sciences.A magnetic field up to 0.8 T is achieved to confine plasmas in a 1.2 m long and 0.1 m diameter vacuum chamber.Gas fluid type analysis in this compact vacuum system was done under high particle flux condition.The gas pressure obtained by calculation was consistent with the measurement result.Continuous argon plasma discharge with ion flux of~0.5×10^(24)m^(-2)s^(-1)is successfully sustained for more than 1h.The effects of magnetic field configuration,gas flow rate,and discharge arc current on the ion flux to target were studied in detail.展开更多
This contribution summarized the recent studies of tungsten-based plasma-facing materials in the linear plasma device like the simulator for tokamak edge plasma(STEP),focusing on the examination of newly developed tun...This contribution summarized the recent studies of tungsten-based plasma-facing materials in the linear plasma device like the simulator for tokamak edge plasma(STEP),focusing on the examination of newly developed tungsten(W)-based materi-als and plasma-induced defects in pure W.Pure W,W-V,W-Y_(2)O_(3)and W-ZrC samples were exposed to a high-flux plasma of~1021-1022 m^(−2)s^(−1) with a fluence up to 1026 m^(−2) at a surface temperature below 500 K.The investigation of fundamental evolution of plasma-induced defects in pure W indicated a critical role of hydrogen-dislocation interactions.Suppressed surface blistering was observed in all W-based materials,but deuterium desorption behavior and retention were distinct with respect to different materials.The studies showed that the linear plasma device like the STEP was indispensable in the understanding of plasma-material interactions and the qualification of new materials for future fusion reactors.展开更多
基金supported by Department of Science and Technology of Jilin Province of China(Nos.YDZJ202301 ZYTS481,202202901032GX,and 20230402068GH)。
文摘Only a small amount of spectral information is collected because the collection solid angle of the optical fiber probe and lens is very limited when collecting spectral information.To overcome this limitation,this study presents a novel method for acquiring plasma spectral information from various spatial directions.A parabolic-shaped plasma spectral collection device(PSCD)is employed to effectively collect more spectral information into the spectrometer,thereby enhancing the overall spectral intensity.The research objects in this study were soil samples containing different concentrations of heavy metals Pb,Cr,and Cd.The results indicate that the PSCD significantly enhances the spectral signal,with an enhancement rate of up to 45%.Moreover,the signal-to-noise ratio also increases by as much as 36%.Simultaneously,when compared to the absence of a device,it is found that there is no significant variation in plasma temperature when the PSCD is utilized.This observation eliminates the impact of the spatial effect caused by the PSCD on the spectral intensity.Consequently,a concentrationspectral intensity relationship curve is established under the PSCD.The results revealed that the linear fitting R^(2)for Pb,Cr,and Cd increased by 0.011,0.001,and 0.054,respectively.Additionally,the limit of detection(LOD)decreased by 0.361 ppm,0.901 ppm,and 0.602 ppm,respectively.These findings indicate that the spectral enhancement rate elevates with the increase in heavy metal concentration.Hence,the PSCD can effectively enhance the spectral intensity and reduce the detection limit of heavy metals in soil.
基金supported by National Natural Science Foundation of China (Nos. 10303003, 40390155, 10605025) and Knowledge Innovation Program of the Chinese Academy of Sciences (No. kjcx-yw-n28)
文摘In order to investigate electron dynamics near the electron diffusion region in mag- netic reconnection process, an upgrade in the linear magnetized plasma (LMP) device is accom- plished at the University of Science and Technology of China. Radio frequency (RF) helicon discharge is used to generate a quasi-stationary plasma, and a time-dependent magnetic field is applied to the plasma, which exhibits an X-type neutral point in vacuum. A two-dimensional sophisticated mobile platform is built up, providing a high spatial resolution, below 0.5 ram, for the diagnostics.
文摘Aluminum alloy 2024 has been implanted with nitrogen ions at various doses by plasma based ion implantation. The introduction of energetic ions causes structural change within the near surface region of the solid. The samples have been characterized by X-ray Photoelectron Spectroscopy at various depths. The chemical states of Al and N were identified by deconvolution of the recorded XPS spectra. After plasma based ion implanted nitrogen into aluminum, not only the AlN precipitates but also super saturated solution of nitrogen forms. The presence of aluminum in different chemical states is corresponding to Al, AlN and Al2O3. The majority of nitrogen is in the form of the supersaturated solution. With the increase of nitrogen dose, the amount of AlN precipitates increases.
文摘The multi-radiation of X-rays was investigated with special attention to their energy spectrum in a Mather-type plasma focus device (operated with argon gas). The analysis is based on the effect of anomalous resistances. To study the energy spectrum, a four-channel diode X-ray spectrometer was used along with a special set of filters. The filters were suitable for detection of medium range X-rays as well as hard X-rays with energy exceeding 30 keV. The results indicate that the anomalous resistivity effect during the post pinch phase may cause multi-radiation of X-rays with a total duration of 300 ± 50 ns. The significant contribution of Cu-Kα was due to the medium range X-rays, nonetheless, hard X-rays with energies greater than 15 keV also participate in the process. The total emitted X-ray energy in the forms of Cu-K and Cu-K/3 was around 0.14 ± 0.02 (J/Sr) and 0.04 ±0.01 (J/Sr), respectively. The total energy of the emitted hard X-ray (〉 15 keV) was around 0.12± 0.02 (J/Sr).
基金supported by Comprehensive Research Facility for Fusion Technology Program of China (No. 2018000052-73-01001228)the Youth Innovation Promotion Association CAS (No. 2018484)
文摘A new compact cascaded arc device for plasma-wall interaction study is developed at the Institute of Plasma Physics,Chinese Academy of Sciences.A magnetic field up to 0.8 T is achieved to confine plasmas in a 1.2 m long and 0.1 m diameter vacuum chamber.Gas fluid type analysis in this compact vacuum system was done under high particle flux condition.The gas pressure obtained by calculation was consistent with the measurement result.Continuous argon plasma discharge with ion flux of~0.5×10^(24)m^(-2)s^(-1)is successfully sustained for more than 1h.The effects of magnetic field configuration,gas flow rate,and discharge arc current on the ion flux to target were studied in detail.
基金the National Nature Science Foundation of China(Grant 51720105006 and 11805007)the Science and Technology on Surface Physics and Chemistry Laboratory(Grant 02020317).
文摘This contribution summarized the recent studies of tungsten-based plasma-facing materials in the linear plasma device like the simulator for tokamak edge plasma(STEP),focusing on the examination of newly developed tungsten(W)-based materi-als and plasma-induced defects in pure W.Pure W,W-V,W-Y_(2)O_(3)and W-ZrC samples were exposed to a high-flux plasma of~1021-1022 m^(−2)s^(−1) with a fluence up to 1026 m^(−2) at a surface temperature below 500 K.The investigation of fundamental evolution of plasma-induced defects in pure W indicated a critical role of hydrogen-dislocation interactions.Suppressed surface blistering was observed in all W-based materials,but deuterium desorption behavior and retention were distinct with respect to different materials.The studies showed that the linear plasma device like the STEP was indispensable in the understanding of plasma-material interactions and the qualification of new materials for future fusion reactors.