The common propellants used for electric thrusters, such as xenon and krypton, are rare, expensive, and difficult to acquire. Solid iodine attracts much attention with the advantages of low cost, extensive availability, low vapor pressure, and ionization potential. The performance of a low-power iodine-fed Hall thruster matched with a xenon-fed cathode is investigated across a broad range of operation conditions. Regulation of the iodine vapor’s mass flow rates is stably achieved by using a temperature control method of the iodine reservoir. The thrust measurements are finished utilizing a thrust target during the tests. Results show that thrust and anode-specific impulse increase approximately linearly with the increasing iodine mass flow rate. At the nominal power of 200 W class, iodine mass flow rates are 0.62 and 0.93 mg/s, thrusts are 7.19 and 7.58 mN, anode specific impulses are 1184 and 826 s, anode efficiencies are 20.8% and 14.5%, and thrust to power ratios are 35.9 and 37.9 mN/kW under the conditions of 250 V 0.8 A and 200 V 1.0 A, respectively. The operating characteristics of iodine-fed Hall thruster are analyzed in different states. Further work on the measurements of plasma characteristics and experimental optimization will be carried out.
电动推进器常用的推进剂，如氙和氪，稀少、昂贵且难以获得。固体碘具有成本低、供应广泛、蒸气压低和电离潜力大等优点，因此备受关注。我们研究了与氙阴极相匹配的低功率碘馈电霍尔推进器在各种运行条件下的性能。通过使用碘储存器的温度控制方法，稳定地实现了碘蒸气质量流量的调节。在测试过程中，利用推力目标完成了推力测量。结果表明，随着碘质量流量的增加，推力和阳极特定冲力大致呈线性增长。在标称功率为 200 W 级时，碘质量流量分别为 0.62 和 0.93 mg/s，推力分别为 7.19 和 7.58 mN，阳极比冲分别为 1184 和 826 s，阳极效率分别为 20.8% 和 14.5%，在 250 V 0.8 A 和 200 V 1.0 A 的条件下，推力与功率比分别为 35.9 和 37.9 mN/kW。分析了碘馈霍尔推进器在不同状态下的运行特性。将进一步开展等离子体特性测量和实验优化工作。
{"title":"Performance investigation of a low-power Hall thruster fed on iodine propellant","authors":"Zongqi Xu, Pingyang Wang, Dongsheng Cai, Rui Tan, Wenjing Jiang","doi":"10.1088/2058-6272/ad240e","DOIUrl":"https://doi.org/10.1088/2058-6272/ad240e","url":null,"abstract":"\u0000 The common propellants used for electric thrusters, such as xenon and krypton, are rare, expensive, and difficult to acquire. Solid iodine attracts much attention with the advantages of low cost, extensive availability, low vapor pressure, and ionization potential. The performance of a low-power iodine-fed Hall thruster matched with a xenon-fed cathode is investigated across a broad range of operation conditions. Regulation of the iodine vapor’s mass flow rates is stably achieved by using a temperature control method of the iodine reservoir. The thrust measurements are finished utilizing a thrust target during the tests. Results show that thrust and anode-specific impulse increase approximately linearly with the increasing iodine mass flow rate. At the nominal power of 200 W class, iodine mass flow rates are 0.62 and 0.93 mg/s, thrusts are 7.19 and 7.58 mN, anode specific impulses are 1184 and 826 s, anode efficiencies are 20.8% and 14.5%, and thrust to power ratios are 35.9 and 37.9 mN/kW under the conditions of 250 V 0.8 A and 200 V 1.0 A, respectively. The operating characteristics of iodine-fed Hall thruster are analyzed in different states. Further work on the measurements of plasma characteristics and experimental optimization will be carried out.","PeriodicalId":506986,"journal":{"name":"Plasma Science and Technology","volume":"308 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140483709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-24DOI: 10.1088/2058-6272/ad225b
Ruohan Zhang, Zhengxiong Wang, Jianyuan Xiao, Feng Wang
Classical Pauli particle (CPP) serves as a slow manifold, substituting the conventional guiding center dynamics. Based on the CPP, we utilize averaged vector field (AVF) method in the computations of drift orbits. Demonstrating significantly higher efficiency, this advanced method is capable of accomplishing the simulation in less than one-third time of directly computing the guiding center motion. In contrast to the CPP-based Boris algorithm, this approach inherits the advantages of the AVF method, yielding stable trajectories even achieved with a tenfold time step and reducing energy error with two orders of magnitude. By comparing these two CPP algorithms with the traditional RK4 method, numerical results indicate the remarkable performance in terms of both computational efficiency and error elimination. Moreover, we verify the properties of slow manifold integrators and successfully observe the bounce on both sides of the limiting slow manifold with initial conditions chosen off. To evaluate the practical value of the methods, we conduct simulations in non-axisymmetric perturbation magnetic fields as part of the experiments, demonstrating our CPP-based AVF method can handle simulations under complex magnetic field configurations with high accuracy, which the CPP-based Boris algorithm lacks. Through numerical experiments, we demonstrate CPP can replace guiding center dynamics in using energy-preserving algorithms for computations, providing a new, efficient, as well as stable approach for applying structure-preserving algorithms in plasma simulations.
{"title":"Structure-preserving algorithms for guiding center dynamics based on the slow manifold of classical Pauli particle","authors":"Ruohan Zhang, Zhengxiong Wang, Jianyuan Xiao, Feng Wang","doi":"10.1088/2058-6272/ad225b","DOIUrl":"https://doi.org/10.1088/2058-6272/ad225b","url":null,"abstract":"\u0000 Classical Pauli particle (CPP) serves as a slow manifold, substituting the conventional guiding center dynamics. Based on the CPP, we utilize averaged vector field (AVF) method in the computations of drift orbits. Demonstrating significantly higher efficiency, this advanced method is capable of accomplishing the simulation in less than one-third time of directly computing the guiding center motion. In contrast to the CPP-based Boris algorithm, this approach inherits the advantages of the AVF method, yielding stable trajectories even achieved with a tenfold time step and reducing energy error with two orders of magnitude. By comparing these two CPP algorithms with the traditional RK4 method, numerical results indicate the remarkable performance in terms of both computational efficiency and error elimination. Moreover, we verify the properties of slow manifold integrators and successfully observe the bounce on both sides of the limiting slow manifold with initial conditions chosen off. To evaluate the practical value of the methods, we conduct simulations in non-axisymmetric perturbation magnetic fields as part of the experiments, demonstrating our CPP-based AVF method can handle simulations under complex magnetic field configurations with high accuracy, which the CPP-based Boris algorithm lacks. Through numerical experiments, we demonstrate CPP can replace guiding center dynamics in using energy-preserving algorithms for computations, providing a new, efficient, as well as stable approach for applying structure-preserving algorithms in plasma simulations.","PeriodicalId":506986,"journal":{"name":"Plasma Science and Technology","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139601911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ammonia is one of the most important chemical raw materials in both manufacture and life of human. Traditionally Haber-Bosch method for ammonia synthesis involves high temperature and high pressure conditions, leading to significant energy consumption and environmental pollution. Non-thermal plasma (NTP) is a promising alternative approach to ammonia synthesis at low temperature and atmospheric pressure. In this study, the synergistic effect of nanosecond pulsed dielectric barrier discharge (np-DBD) and Ni-MOF-74 catalyst was investigated in ammonia synthesis by utilizing nitrogen and hydrogen as feedstock. The results demonstrated that the plasma catalytic-synthesis process parameters play a crucial role in the synthesis process of ammonia. The highest ammonia synthesis rate of 5145.16 μmol·g−1·h−1 with an energy efficiency of 1.27 g·kWh−1 was observed in the presence of the Ni-MOF-74 catalyst, which was 3.7 times higher than that without Ni-MOF-74 catalyst. The synergistic effect of Ni-MOF-74 catalyst and nanosecond pulsed plasma was explored by in-situ plasma discharge diagnostics.
{"title":"Dielectric barrier discharge plasma-assisted catalytic ammonia synthesis: synergistic effect of Ni-MOF-74 catalyst and nanosecond pulsed plasma","authors":"Xiaofang Xu, Meng Sun, Qinlong Song, Xuan Wu, Chongchong Chen, Chen Qiang, Haibao Zhang","doi":"10.1088/2058-6272/ad1fd8","DOIUrl":"https://doi.org/10.1088/2058-6272/ad1fd8","url":null,"abstract":"\u0000 Ammonia is one of the most important chemical raw materials in both manufacture and life of human. Traditionally Haber-Bosch method for ammonia synthesis involves high temperature and high pressure conditions, leading to significant energy consumption and environmental pollution. Non-thermal plasma (NTP) is a promising alternative approach to ammonia synthesis at low temperature and atmospheric pressure. In this study, the synergistic effect of nanosecond pulsed dielectric barrier discharge (np-DBD) and Ni-MOF-74 catalyst was investigated in ammonia synthesis by utilizing nitrogen and hydrogen as feedstock. The results demonstrated that the plasma catalytic-synthesis process parameters play a crucial role in the synthesis process of ammonia. The highest ammonia synthesis rate of 5145.16 μmol·g−1·h−1 with an energy efficiency of 1.27 g·kWh−1 was observed in the presence of the Ni-MOF-74 catalyst, which was 3.7 times higher than that without Ni-MOF-74 catalyst. The synergistic effect of Ni-MOF-74 catalyst and nanosecond pulsed plasma was explored by in-situ plasma discharge diagnostics.","PeriodicalId":506986,"journal":{"name":"Plasma Science and Technology","volume":" 765","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139617712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-17DOI: 10.1088/2058-6272/ad1fd9
Shouxian Tang, Di Tian, Zheng Li, Zhengduo Wang, Bowen Liu, jiushan Cheng, Zhongwei Liu
Supported Pd catalyst is an important noble metal material in recent years due to its high catalytic performance in CO2 hydrogenation. An fluidized-bed plasma assisted atomic layer deposition (FP-ALD) process is reported to fabricate Pd nanoparticle catalyst over γ-Al2O3 or Fe2O3/γ-Al2O3 support, using palladium hexafluoroacetylacetonate as the Pd precursor and H2 plasma as counter-reactant. Scanning transmission electron microscopy exhibits that high-density Pd nanoparticles are uniformly dispersed over Fe2O3/γ-Al2O3 support with an average diameter of 4.4 nm. The deposited Pd-Fe2O3/γ-Al2O3 shows excellent catalytic performance for CO2 hydrogenation in a dielectric barrier discharge reactor. Under a typical condition of H2 to CO2 ratio of 4 in the feed gas, the discharge power of 19.6 W, and gas hourly space velocity of 10000 h-1, the conversion of CO2 is as high as 16.3 % with CH3OH and CH4 selectivities of 26.5 % and 3.9 %, respectively.
{"title":"Preparation of palladium-based catalyst by plasma-assisted atomic layer deposition and its applications in CO2 hydrogenation reduction","authors":"Shouxian Tang, Di Tian, Zheng Li, Zhengduo Wang, Bowen Liu, jiushan Cheng, Zhongwei Liu","doi":"10.1088/2058-6272/ad1fd9","DOIUrl":"https://doi.org/10.1088/2058-6272/ad1fd9","url":null,"abstract":"\u0000 Supported Pd catalyst is an important noble metal material in recent years due to its high catalytic performance in CO2 hydrogenation. An fluidized-bed plasma assisted atomic layer deposition (FP-ALD) process is reported to fabricate Pd nanoparticle catalyst over γ-Al2O3 or Fe2O3/γ-Al2O3 support, using palladium hexafluoroacetylacetonate as the Pd precursor and H2 plasma as counter-reactant. Scanning transmission electron microscopy exhibits that high-density Pd nanoparticles are uniformly dispersed over Fe2O3/γ-Al2O3 support with an average diameter of 4.4 nm. The deposited Pd-Fe2O3/γ-Al2O3 shows excellent catalytic performance for CO2 hydrogenation in a dielectric barrier discharge reactor. Under a typical condition of H2 to CO2 ratio of 4 in the feed gas, the discharge power of 19.6 W, and gas hourly space velocity of 10000 h-1, the conversion of CO2 is as high as 16.3 % with CH3OH and CH4 selectivities of 26.5 % and 3.9 %, respectively.","PeriodicalId":506986,"journal":{"name":"Plasma Science and Technology","volume":" 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139617258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-16DOI: 10.1088/2058-6272/ad1f42
Lu Zhang, Liling Li, Zhiwei Lin, Yunsong Dong, L. Jing, Jianhua Zheng, L. Kuang, Hang Li, Jinhua Zheng, Jiyan Zhang, T. Song, Zhiyu Zhang, Yang Zhao, Gao Niu, Dong Yang, Jiamin Yang, Yongkun Ding
In indirect-driven laser fusion experiments, the movement of the laser absorption layer will distort the radiation uniformity on the capsule. The gold foam has advantages in symmetry control and lowering wall plasma blowoff when used in an inertial confinement fusion (ICF) hohlraum. This work investigates the motion of the laser absorption cutoff position using low density foam gold walls. It is found that the motion of the laser absorption cutoff position can be significantly mitigated through optimal initial low density, tailored to a specific laser shape. For a short square laser pulse, the laser absorption cutoff position remains nearly stationary at an initial density of approximately 0.6 g cm−3. For a long-shaped laser pulse, the minimal motion of the laser absorption cutoff position is observed at an initial density of about 0.1 g cm−3. This approach allows for the adjustment of the symmetry of the hohlraum radiation source. The insights gained from this study serve as a crucial reference for optimizing hohlraum wall density.
在间接驱动激光聚变实验中，激光吸收层的移动会扭曲舱体上的辐射均匀性。在惯性约束聚变（ICF）舱中使用泡沫金，在对称性控制和降低舱壁等离子体喷发方面具有优势。这项工作研究了使用低密度泡沫金壁的激光吸收截止位置的运动。研究发现，根据特定的激光形状，通过优化初始低密度，可以显著减缓激光吸收截止位置的移动。对于短方形激光脉冲，在初始密度约为 0.6 g cm-3 时，激光吸收截止位置几乎保持静止。对于长形激光脉冲，在初始密度约为 0.1 g cm-3 时，激光吸收截止位置的运动最小。通过这种方法可以调整浩室辐射源的对称性。这项研究获得的启示为优化氦墙密度提供了重要参考。
{"title":"Tamping the movement of the laser absorption cutoff position by using gold foam hohlraum","authors":"Lu Zhang, Liling Li, Zhiwei Lin, Yunsong Dong, L. Jing, Jianhua Zheng, L. Kuang, Hang Li, Jinhua Zheng, Jiyan Zhang, T. Song, Zhiyu Zhang, Yang Zhao, Gao Niu, Dong Yang, Jiamin Yang, Yongkun Ding","doi":"10.1088/2058-6272/ad1f42","DOIUrl":"https://doi.org/10.1088/2058-6272/ad1f42","url":null,"abstract":"\u0000 In indirect-driven laser fusion experiments, the movement of the laser absorption layer will distort the radiation uniformity on the capsule. The gold foam has advantages in symmetry control and lowering wall plasma blowoff when used in an inertial confinement fusion (ICF) hohlraum. This work investigates the motion of the laser absorption cutoff position using low density foam gold walls. It is found that the motion of the laser absorption cutoff position can be significantly mitigated through optimal initial low density, tailored to a specific laser shape. For a short square laser pulse, the laser absorption cutoff position remains nearly stationary at an initial density of approximately 0.6 g cm−3. For a long-shaped laser pulse, the minimal motion of the laser absorption cutoff position is observed at an initial density of about 0.1 g cm−3. This approach allows for the adjustment of the symmetry of the hohlraum radiation source. The insights gained from this study serve as a crucial reference for optimizing hohlraum wall density.","PeriodicalId":506986,"journal":{"name":"Plasma Science and Technology","volume":"48 33","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139528104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-15DOI: 10.1088/2058-6272/ad1ed1
Zhen Song, Junxiao Wang, Gang Wang, Lei Zhang, Shuqing Wang, Wan Zhang, Xiaofei Ma, Zhenrong Liu, Xue Luo, W. Ma, Zefu Ye, Zhujun Zhu, W. Yin, S. Jia
In the field of dual-pulse laser-induced breakdown spectroscopy (DP-LIBS) research, the pursuit for determining pulse interval and other parameters quickly and conveniently in order to achieve optimal spectral signal enhancement is paramount. To aid researchers in identifying the optimal signal enhancement conditions and more accurately interpreting the underlying signal enhancement mechanisms, theoretical simulations of the spatiotemporal processes of coaxial DP-LIBS plasma inducing have been established in this work. By means of a model based on laser ablation and two-dimensional axisymmetric fluid dynamics, plasma evolution during aluminum-magnesium alloy laser ablation under single pulse and coaxial dual pulse excitations have been simulated. The influence of factors such as delay time, laser fluence, plasma temperature, particle number density, etc., on the DP-LIBS spectral signals are investigated. Under pulse intervals ranging from 50 to 1500 ns, the time evolution of spectral line intensity, dual-pulse emission enhancement relative to the single-pulse results, laser irradiance, spatial distribution of plasma temperature and species number density, as well as laser irradiance shielded by plasma have been obtained. The study indicates that the main reason behind the radiation signal enhancement in coaxial DP-LIBS induced plasma is attributed to increased species number density and plasma temperature caused by the second laser, and it is inferred that the shielding effect of the plasma mainly occurs in the boundary layer of the stagnation point flow over the target surface. This research provides a theoretical basis for experimental research, parameter optimization, and signal enhancement tracing in DP-LIBS.
{"title":"Theoretical study on signal enhancement mechanism of coaxial DP-LIBS","authors":"Zhen Song, Junxiao Wang, Gang Wang, Lei Zhang, Shuqing Wang, Wan Zhang, Xiaofei Ma, Zhenrong Liu, Xue Luo, W. Ma, Zefu Ye, Zhujun Zhu, W. Yin, S. Jia","doi":"10.1088/2058-6272/ad1ed1","DOIUrl":"https://doi.org/10.1088/2058-6272/ad1ed1","url":null,"abstract":"\u0000 In the field of dual-pulse laser-induced breakdown spectroscopy (DP-LIBS) research, the pursuit for determining pulse interval and other parameters quickly and conveniently in order to achieve optimal spectral signal enhancement is paramount. To aid researchers in identifying the optimal signal enhancement conditions and more accurately interpreting the underlying signal enhancement mechanisms, theoretical simulations of the spatiotemporal processes of coaxial DP-LIBS plasma inducing have been established in this work. By means of a model based on laser ablation and two-dimensional axisymmetric fluid dynamics, plasma evolution during aluminum-magnesium alloy laser ablation under single pulse and coaxial dual pulse excitations have been simulated. The influence of factors such as delay time, laser fluence, plasma temperature, particle number density, etc., on the DP-LIBS spectral signals are investigated. Under pulse intervals ranging from 50 to 1500 ns, the time evolution of spectral line intensity, dual-pulse emission enhancement relative to the single-pulse results, laser irradiance, spatial distribution of plasma temperature and species number density, as well as laser irradiance shielded by plasma have been obtained. The study indicates that the main reason behind the radiation signal enhancement in coaxial DP-LIBS induced plasma is attributed to increased species number density and plasma temperature caused by the second laser, and it is inferred that the shielding effect of the plasma mainly occurs in the boundary layer of the stagnation point flow over the target surface. This research provides a theoretical basis for experimental research, parameter optimization, and signal enhancement tracing in DP-LIBS.","PeriodicalId":506986,"journal":{"name":"Plasma Science and Technology","volume":" 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139623146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-12DOI: 10.1088/2058-6272/ad1e1c
C. Chen, Dongyu Peng, Botong Liu, Tinglin Zhang, Muyang Qian, Feng Zhou, Rugang Wang
Nanosecond pulsed discharges at atmospheric pressure in a pin-to-pin electrode configuration are well reproducible in time and space, which is beneficial to fundamentals and applications of low temperature plasmas. In this experiment, the discharges in helium (He) and He with 2.3% water vapor (H2O) are driven by a series of 10 ns overvoltage pulses (~13 kV). Special attention is paid on the spectral characteristics obtained in the center of discharges by time resolved optical emission spectroscopy. It is found that in the case of helium the emission of atomic and molecular helium during the afterglow is more intense than that in the active discharge, while in the case of He+2.3%H2O mixture the helium emission is only observed during the discharge pulse and the molecular helium emission disappears. In addition, the emissions of OH(A-X) and Hα present a similar behavior that increases sharply during the falling edge of voltage pulse as the electrons cool down rapidly. The gas temperature is determined to remain low at 540 K by fitting the OH(A-X) band. A comparative study on the emission of radiative species (He, He2, OH and H) is performed between these two cases of discharges to derive their main production mechanisms. In both cases, the dominant primary ion is He+ at the onset of discharges but their charge transfer processes of He+ are quite different. Based on these experimental data and qualitative discussion on the discharge kinetics, as for the present discharge conditions, it is shown that the electron-assisted three-body recombination processes appear to be the significant sources of radiative OH and H species in high-density plasmas.
{"title":"Comparative study on spectral characteristics of nanosecond pulsed discharges in atmospheric He and He+2.3%H2O mixture","authors":"C. Chen, Dongyu Peng, Botong Liu, Tinglin Zhang, Muyang Qian, Feng Zhou, Rugang Wang","doi":"10.1088/2058-6272/ad1e1c","DOIUrl":"https://doi.org/10.1088/2058-6272/ad1e1c","url":null,"abstract":"\u0000 Nanosecond pulsed discharges at atmospheric pressure in a pin-to-pin electrode configuration are well reproducible in time and space, which is beneficial to fundamentals and applications of low temperature plasmas. In this experiment, the discharges in helium (He) and He with 2.3% water vapor (H2O) are driven by a series of 10 ns overvoltage pulses (~13 kV). Special attention is paid on the spectral characteristics obtained in the center of discharges by time resolved optical emission spectroscopy. It is found that in the case of helium the emission of atomic and molecular helium during the afterglow is more intense than that in the active discharge, while in the case of He+2.3%H2O mixture the helium emission is only observed during the discharge pulse and the molecular helium emission disappears. In addition, the emissions of OH(A-X) and Hα present a similar behavior that increases sharply during the falling edge of voltage pulse as the electrons cool down rapidly. The gas temperature is determined to remain low at 540 K by fitting the OH(A-X) band. A comparative study on the emission of radiative species (He, He2, OH and H) is performed between these two cases of discharges to derive their main production mechanisms. In both cases, the dominant primary ion is He+ at the onset of discharges but their charge transfer processes of He+ are quite different. Based on these experimental data and qualitative discussion on the discharge kinetics, as for the present discharge conditions, it is shown that the electron-assisted three-body recombination processes appear to be the significant sources of radiative OH and H species in high-density plasmas.","PeriodicalId":506986,"journal":{"name":"Plasma Science and Technology","volume":" 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139624401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-04DOI: 10.1088/2058-6272/ad1b0e
Jun Jiang, Yingying Li, Ran Chen, J. Fu, Bo Lyu, Yi Yu, Guosheng Xu, Minyou Ye
An ultra-fast charge exchange recombination spectroscopy (UF-CXRS) has been developed on EAST tokamak (Yingying Li et al 2019 Fusion Eng. Des. 146 522-525) to measure fast evolution of ion temperature and toroidal velocity. Here we report the preliminary diagnostic measurements after relative sensitivity calibration. The measurement results show a much higher temporal resolution compared with conventional CXRS benefiting from the usage of a prism-coupled, high-dispersion VPH transmission grating and a high-quantum efficiency, high-gain detector array. Utilizing the UF-CXRS diagnostic, the fast evolutions of the ion temperature and rotation velocity during a set of high-frequency small-amplitude ELMs are obtained on the EAST tokamak, which are then compared with the case of large-amplitude ELMs.
在 EAST 托卡马克上开发了超快电荷交换重组光谱（UF-CXRS）（Yingying Li et al 2019 Fusion Eng. Des. 146 522-525），用于测量离子温度和环速的快速演变。在此，我们报告相对灵敏度校准后的初步诊断测量结果。测量结果表明，与传统的 CXRS 相比，UF-CXRS 具有更高的时间分辨率，这得益于它使用了棱镜耦合、高色散 VPH 传输光栅和高量子效率、高增益探测器阵列。利用 UF-CXRS 诊断，在 EAST 托卡马克上获得了一组高频小振幅 ELM 期间离子温度和旋转速度的快速演变，然后将其与大振幅 ELM 的情况进行比较。
{"title":"Initial measurement of ultrafast charge exchange recombination spectroscopy on the EAST tokamak","authors":"Jun Jiang, Yingying Li, Ran Chen, J. Fu, Bo Lyu, Yi Yu, Guosheng Xu, Minyou Ye","doi":"10.1088/2058-6272/ad1b0e","DOIUrl":"https://doi.org/10.1088/2058-6272/ad1b0e","url":null,"abstract":"\u0000 An ultra-fast charge exchange recombination spectroscopy (UF-CXRS) has been developed on EAST tokamak (Yingying Li et al 2019 Fusion Eng. Des. 146 522-525) to measure fast evolution of ion temperature and toroidal velocity. Here we report the preliminary diagnostic measurements after relative sensitivity calibration. The measurement results show a much higher temporal resolution compared with conventional CXRS benefiting from the usage of a prism-coupled, high-dispersion VPH transmission grating and a high-quantum efficiency, high-gain detector array. Utilizing the UF-CXRS diagnostic, the fast evolutions of the ion temperature and rotation velocity during a set of high-frequency small-amplitude ELMs are obtained on the EAST tokamak, which are then compared with the case of large-amplitude ELMs.","PeriodicalId":506986,"journal":{"name":"Plasma Science and Technology","volume":"18 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139386435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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