Pub Date : 2023-12-08DOI: 10.1088/2058-6272/ad13e4
Xingyu Chen, Mengqi Li, Quanzhi Zhang, Tao Peng, Z. Xiong
The discharge morphology of pulsed dielectric barrier discharge (PDBD) plays important roles in its applications. Here, we systematically investigated the effects of voltage amplitude, discharge gap, and O2 content on the PDBD morphology, and revealed the possible underlying mechanism of the U-shape formation. First, the morphological evolution under different conditions were recorded. A unique U-shape region appears in the middle edge region when the gap is larger than 2 mm, while the entire discharge region remains columnar under a 2 mm gap in He PDBD. The width of the discharge and the U-shape region increase with the increase of voltage and decreases with the increase of the gap and O2 content. To explain this phenomenon, then a two-dimensional symmetric model was developed to simulate the spatiotemporal evolution of different species and calculate the electric thrust. The discharge morphology evolution directly corresponds to the excited state atomic reduction process. The electric thrust on the charged particles mainly determines the reaction region and strongly influences the U-shape formation. When the gap is less than 2 mm, the electric thrust is homogeneous throughout the entire region, resulting in a columnar shape. However, when the gap is larger than 2 mm or O2 is added, the electric thrust in the edge region becomes greater than that in the middle, leading to the U-shape formation. Furthermore, in He PDBD, the charged particles generating electric thrust are mainly electrons and helium ions, while in He/O2 PDBD those generate electric thrust at the outer edge of the electrode surface are mainly various oxygen-containing ions.
{"title":"On the evolution and formation of discharge morphology in pulsed dielectric barrier discharge","authors":"Xingyu Chen, Mengqi Li, Quanzhi Zhang, Tao Peng, Z. Xiong","doi":"10.1088/2058-6272/ad13e4","DOIUrl":"https://doi.org/10.1088/2058-6272/ad13e4","url":null,"abstract":"\u0000 The discharge morphology of pulsed dielectric barrier discharge (PDBD) plays important roles in its applications. Here, we systematically investigated the effects of voltage amplitude, discharge gap, and O2 content on the PDBD morphology, and revealed the possible underlying mechanism of the U-shape formation. First, the morphological evolution under different conditions were recorded. A unique U-shape region appears in the middle edge region when the gap is larger than 2 mm, while the entire discharge region remains columnar under a 2 mm gap in He PDBD. The width of the discharge and the U-shape region increase with the increase of voltage and decreases with the increase of the gap and O2 content. To explain this phenomenon, then a two-dimensional symmetric model was developed to simulate the spatiotemporal evolution of different species and calculate the electric thrust. The discharge morphology evolution directly corresponds to the excited state atomic reduction process. The electric thrust on the charged particles mainly determines the reaction region and strongly influences the U-shape formation. When the gap is less than 2 mm, the electric thrust is homogeneous throughout the entire region, resulting in a columnar shape. However, when the gap is larger than 2 mm or O2 is added, the electric thrust in the edge region becomes greater than that in the middle, leading to the U-shape formation. Furthermore, in He PDBD, the charged particles generating electric thrust are mainly electrons and helium ions, while in He/O2 PDBD those generate electric thrust at the outer edge of the electrode surface are mainly various oxygen-containing ions.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138589912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many magnetohydrodynamic stability analysis requires generation of a set of equilibria with fixed safety factor q-profile while varying other plasma parameters. A neural network (NN)-based approach is investigated that facilitates such a process. Both the multi-layer perceptron (MLP) based NN and the convolutional neural network (CNN) models are trained to map the q-profile to the plasma current density J-profile and vice versa, while satisfying the Grad-Shafranov radial force balance constraint. When the initial target models are trained, using a database of semi-analytically constructed numerical equilibria, the initial CNN with one convolutional layer is found to perform better than the initial MLP model. In particular, the trained initial CNN model can also predict the q- or J-profile for experimental tokamak equilibria. The performance of both initial target models is further improved by fine-tuning the training database, i.e., by adding realistic experimental equilibria with Gaussian noise. The fine-tuned target models, referred to as fine-tuned MLP and fine-tuned CNN, well reproduce the target q- or J-profile across multiple tokamak devices. As an important application, these NN-based equilibrium profile convertors can be utilized to provide good initial guess for iterative equilibrium solvers, where the desired input quantity is the safety factor instead of the plasma current density.
{"title":"Deep learning approaches to recover plasma current density profile from safety factor based on Grad-Shafranov solutions across multiple tokamaks","authors":"Hanyu Zhang, Lina Zhou, Yueqiang Liu, Guangzhou Hao, Shuo Wang, Xu Yang, Yutian Miao, Ping Duan, Long Chen","doi":"10.1088/2058-6272/ad13e3","DOIUrl":"https://doi.org/10.1088/2058-6272/ad13e3","url":null,"abstract":"\u0000 Many magnetohydrodynamic stability analysis requires generation of a set of equilibria with fixed safety factor q-profile while varying other plasma parameters. A neural network (NN)-based approach is investigated that facilitates such a process. Both the multi-layer perceptron (MLP) based NN and the convolutional neural network (CNN) models are trained to map the q-profile to the plasma current density J-profile and vice versa, while satisfying the Grad-Shafranov radial force balance constraint. When the initial target models are trained, using a database of semi-analytically constructed numerical equilibria, the initial CNN with one convolutional layer is found to perform better than the initial MLP model. In particular, the trained initial CNN model can also predict the q- or J-profile for experimental tokamak equilibria. The performance of both initial target models is further improved by fine-tuning the training database, i.e., by adding realistic experimental equilibria with Gaussian noise. The fine-tuned target models, referred to as fine-tuned MLP and fine-tuned CNN, well reproduce the target q- or J-profile across multiple tokamak devices. As an important application, these NN-based equilibrium profile convertors can be utilized to provide good initial guess for iterative equilibrium solvers, where the desired input quantity is the safety factor instead of the plasma current density.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138587790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-07DOI: 10.1088/2058-6272/ad1365
Wen Shi, Pengfei Yang, Peiyi Song, Jian Wu
Electrospray is a technique used to break and atomize a liquid medium via electric force. This technique holds significant potential for various applications, particularly in the field of ionic liquid electrospray (ILE) technology. However, when ILE is conducted in high-voltage atmospheric environments, gas discharge phenomena often occur. These phenomena disrupt the normal operation of electrospray and the measurement of experimental parameters. In this study, electrospray experiments were conducted on the ionic liquid EMI-BF4. The observations revealed that the operating modes of the ionic liquid depend on the voltage polarity at high voltages. Additionally, a correspondence between the operating mode of ILE and the current signal in the circuit was established. The shape of the liquid cone formed at the needle tip bore a striking resemblance to the plume of corona discharge, suggesting that the motion trajectory of electrons influenced the curvature of the liquid cone. Steamer theory provided a clear explanation for the change in curvature as the voltage increased.
{"title":"Experimental study of the effect of gas discharge on ionic liquid electrospray","authors":"Wen Shi, Pengfei Yang, Peiyi Song, Jian Wu","doi":"10.1088/2058-6272/ad1365","DOIUrl":"https://doi.org/10.1088/2058-6272/ad1365","url":null,"abstract":"\u0000 Electrospray is a technique used to break and atomize a liquid medium via electric force. This technique holds significant potential for various applications, particularly in the field of ionic liquid electrospray (ILE) technology. However, when ILE is conducted in high-voltage atmospheric environments, gas discharge phenomena often occur. These phenomena disrupt the normal operation of electrospray and the measurement of experimental parameters. In this study, electrospray experiments were conducted on the ionic liquid EMI-BF4. The observations revealed that the operating modes of the ionic liquid depend on the voltage polarity at high voltages. Additionally, a correspondence between the operating mode of ILE and the current signal in the circuit was established. The shape of the liquid cone formed at the needle tip bore a striking resemblance to the plume of corona discharge, suggesting that the motion trajectory of electrons influenced the curvature of the liquid cone. Steamer theory provided a clear explanation for the change in curvature as the voltage increased.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138591297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A toroidal soft X-ray imaging (T-SXRI) system has been developed to investigate the three-dimensional (3D) plasma physics on J-TEXT. This T-SXRI system consists of three sets of SXR arrays. Two sets are newly developed and located on the vacuum chamber wall at toroidal position ϕ of 126.4° and 272.6°, respectively, while one set is established previously at ϕ = 65.5°. Each set of SXR arrays consists of 3 arrays viewing the plasma poloidally, and hence can be used separately to obtain the SXR imaging via the tomographic method. The sawtooth precursor oscillations are measured by T-SXRI. The corresponding images of SXR perturbations are successfully reconstructed at three toroidal positions, hence forms a 3D measurement of the sawtooth precursor. The observed 3D structure is consistent with the helical structure of the m/n = 1/1 mode. The experimental observation confirms that the T-SXRI system is capable of observing the 3D structure of the plasma.
{"title":"Development of toroidal soft X-ray imaging system and application for investigating three-dimensional plasma on J-TEXT","authors":"Chuanxu Zhao, Jianchao Li, Xiaoqing Zhang, Nengchao Wang, Yonghua Ding, Zhoujun Yang, Zhonghe Jiang, W. Yan, Yangbo Li, Feiyue Mao, Zhengkang Ren","doi":"10.1088/2058-6272/ad1364","DOIUrl":"https://doi.org/10.1088/2058-6272/ad1364","url":null,"abstract":"\u0000 A toroidal soft X-ray imaging (T-SXRI) system has been developed to investigate the three-dimensional (3D) plasma physics on J-TEXT. This T-SXRI system consists of three sets of SXR arrays. Two sets are newly developed and located on the vacuum chamber wall at toroidal position ϕ of 126.4° and 272.6°, respectively, while one set is established previously at ϕ = 65.5°. Each set of SXR arrays consists of 3 arrays viewing the plasma poloidally, and hence can be used separately to obtain the SXR imaging via the tomographic method. The sawtooth precursor oscillations are measured by T-SXRI. The corresponding images of SXR perturbations are successfully reconstructed at three toroidal positions, hence forms a 3D measurement of the sawtooth precursor. The observed 3D structure is consistent with the helical structure of the m/n = 1/1 mode. The experimental observation confirms that the T-SXRI system is capable of observing the 3D structure of the plasma.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138591485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Far-infrared (FIR) interferometer is widely used to measure the electron density in the magnetically confined fusion plasma devices. A new FIR laser interferometer with a total of 13 channels (including 8 horizontal channels and 5 oblique channels) is under development for the HL-3 tokamak by using the formic-acid laser (HCOOH, f = 694 GHz). In order to investigate the boundary electron density activity, three horizontal interferometry channels located at Z = −97, −76, 76.5 cm have just been developed and put into operation in 2023 experimental campaign, with a time resolution of < 1.0 μs and line-integrated electron density resolution of ~ 7.0×1016 m−2. This paper mainly focuses on the optical design of the three-channel interferometry system, optical elements and recent experimental result on HL-3.
{"title":"Electron density measurement by the three boundary channels of HCOOH laser interferometer on the HL-3 tokamak","authors":"Junren Mou, Yonggao Li, Yuan Li, Zaihong Wang, Baogang Ding, Haoxi Wang, Jiang Yi, Zhongbing Shi","doi":"10.1088/2058-6272/ad127a","DOIUrl":"https://doi.org/10.1088/2058-6272/ad127a","url":null,"abstract":"\u0000 Far-infrared (FIR) interferometer is widely used to measure the electron density in the magnetically confined fusion plasma devices. A new FIR laser interferometer with a total of 13 channels (including 8 horizontal channels and 5 oblique channels) is under development for the HL-3 tokamak by using the formic-acid laser (HCOOH, f = 694 GHz). In order to investigate the boundary electron density activity, three horizontal interferometry channels located at Z = −97, −76, 76.5 cm have just been developed and put into operation in 2023 experimental campaign, with a time resolution of < 1.0 μs and line-integrated electron density resolution of ~ 7.0×1016 m−2. This paper mainly focuses on the optical design of the three-channel interferometry system, optical elements and recent experimental result on HL-3.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138598677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1088/2058-6272/ad1194
Jinhong Wei, Song Li, Hong Chen, Fanzheng Zeng, Chenglin Jia, Zebin Fu, Xingjun Ge, Baoliang Qian
To guide the illuminating design to improve the on-state performances of gallium arsenide (GaAs) photoconductive semiconductor switch (PCSS), the effect of spot size on the operation mode of GaAs PCSS based on a semi-insulating wafer with a thickness of 1 mm, triggered by a 1064-nm extrinsic laser beam with the rectangular spot, has been investigated experimentally. It is found that the variation of the spot size in length and width can act on the different parts of the output waveform integrating the characteristics of the linear and nonlinear modes, and then significantly boosts the PCSS toward different operation modes. On this basis, a two-channel model containing the active and passive parts is introduced to interpret the relevant influencing mechanisms. Results indicate that the increased spot length can peak the amplitude of static domains in the active part to enhance the development of the nonlinear switching, while the extended spot width can change the distribution of photogenerated carriers on both parts to facilitate the linear switching and weaken the nonlinear switching, which have been proved by comparing the domain evolutions under different spot sizes.
{"title":"Effects of spot size on the operation mode of GaAs PCSS employing extrinsic photoconductivity","authors":"Jinhong Wei, Song Li, Hong Chen, Fanzheng Zeng, Chenglin Jia, Zebin Fu, Xingjun Ge, Baoliang Qian","doi":"10.1088/2058-6272/ad1194","DOIUrl":"https://doi.org/10.1088/2058-6272/ad1194","url":null,"abstract":"\u0000 To guide the illuminating design to improve the on-state performances of gallium arsenide (GaAs) photoconductive semiconductor switch (PCSS), the effect of spot size on the operation mode of GaAs PCSS based on a semi-insulating wafer with a thickness of 1 mm, triggered by a 1064-nm extrinsic laser beam with the rectangular spot, has been investigated experimentally. It is found that the variation of the spot size in length and width can act on the different parts of the output waveform integrating the characteristics of the linear and nonlinear modes, and then significantly boosts the PCSS toward different operation modes. On this basis, a two-channel model containing the active and passive parts is introduced to interpret the relevant influencing mechanisms. Results indicate that the increased spot length can peak the amplitude of static domains in the active part to enhance the development of the nonlinear switching, while the extended spot width can change the distribution of photogenerated carriers on both parts to facilitate the linear switching and weaken the nonlinear switching, which have been proved by comparing the domain evolutions under different spot sizes.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138611389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1088/2058-6272/ad1195
Jianwen Liu, Qing Zang, Yunfeng Liang, Jiale Chen, Xiaohe Wu, Alexander Knieps, Jiahui Hu, Yifei Jin, Bin Zhang, Yuqi Chu, Haiqing Liu, Bo Lyu, Yanmin Duan, Miaohui Li, Yingjie Chen, Xianzu Gong
At the EAST tokamak, the ion temperature (Ti) is observed to be clamped around 1.25 keV in ECR-heated plasmas, even at core electron temperatures up to 10 keV (depending on the electron cyclotron resonance heating (ECRH) power and the plasma density). This clamping results from the lack of direct ion heating and high levels of turbulence driven transport. Turbulent transport analysis shows that trapped electron mode (TEM) and electron temperature gradient (ETG) driven modes are the most unstable modes in the core of ECR-heated H-mode plasmas. Nevertheless, recently it was found that the Ti/Te ratio can increase further with the fraction of the Neutral Beam Injection (NBI) power, which leads to a higher core ion temperature (Ti0). In NBI-heating-dominant H-mode plasmas, the ion temperature gradient (ITG) driven modes become the most unstable modes. Furthermore, a strong and broad internal transport barrier (ITB) can form at the plasma core in high-power NBI heated H-mode plasmas when the Ti/Te ratio approaches ~1, which results in steep core Te and Ti profiles, as well as a peaked ne profile. Power balance analysis shows a weaker Te profile stiffness after the formation of ITBs in the core plasma region, where Ti clamping is broken, and the core Ti can increase further above 2 keV, which is 80% higher than the value of Ti clamping in ECR-heated plasmas. This finding proposes a possible solution to the problem of Ti clamping in EAST and demonstrates an advanced operational regime with formation of a strong and broad ITB for future fusion plasmas dominated by electron heating.
{"title":"Impact of T_i⁄T_e ratio on ion transport based on EAST H-mode plasmas","authors":"Jianwen Liu, Qing Zang, Yunfeng Liang, Jiale Chen, Xiaohe Wu, Alexander Knieps, Jiahui Hu, Yifei Jin, Bin Zhang, Yuqi Chu, Haiqing Liu, Bo Lyu, Yanmin Duan, Miaohui Li, Yingjie Chen, Xianzu Gong","doi":"10.1088/2058-6272/ad1195","DOIUrl":"https://doi.org/10.1088/2058-6272/ad1195","url":null,"abstract":"\u0000 At the EAST tokamak, the ion temperature (Ti) is observed to be clamped around 1.25 keV in ECR-heated plasmas, even at core electron temperatures up to 10 keV (depending on the electron cyclotron resonance heating (ECRH) power and the plasma density). This clamping results from the lack of direct ion heating and high levels of turbulence driven transport. Turbulent transport analysis shows that trapped electron mode (TEM) and electron temperature gradient (ETG) driven modes are the most unstable modes in the core of ECR-heated H-mode plasmas. Nevertheless, recently it was found that the Ti/Te ratio can increase further with the fraction of the Neutral Beam Injection (NBI) power, which leads to a higher core ion temperature (Ti0). In NBI-heating-dominant H-mode plasmas, the ion temperature gradient (ITG) driven modes become the most unstable modes. Furthermore, a strong and broad internal transport barrier (ITB) can form at the plasma core in high-power NBI heated H-mode plasmas when the Ti/Te ratio approaches ~1, which results in steep core Te and Ti profiles, as well as a peaked ne profile. Power balance analysis shows a weaker Te profile stiffness after the formation of ITBs in the core plasma region, where Ti clamping is broken, and the core Ti can increase further above 2 keV, which is 80% higher than the value of Ti clamping in ECR-heated plasmas. This finding proposes a possible solution to the problem of Ti clamping in EAST and demonstrates an advanced operational regime with formation of a strong and broad ITB for future fusion plasmas dominated by electron heating.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138615695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-30DOI: 10.1088/2058-6272/ad113e
Weijie Huo, Weiguo He, Luofeng Han, Kangwu Zhu, Feng Wang
In this study, a pulsed, high voltage driven hollow-cathode electron beam sources through an optical trigger is designed with characteristics of simple structure, low cost, and easy triggering. To validate the new design, the characteristics of hollow-cathode discharge and electron beam characterization under pulsed high voltage drive are studied experimentally and discussed by discharge characteristics and analyses of waveform details, respectively. The validation experiments indicate that the pulsed high voltage supply significantly improves the frequency and stability of the discharge, which provides a new solution for the realization of a high-frequency, high-energy electron beam source. The peak current amplitude in the high-energy electron beam increases from 6.2 A to 79.6 A, which indicates the pulsed power mode significantly improves the electron beam performance. Besides, increasing the capacitance significantly affects the high-current, lower-energy electron beam more than the highenergy electron beam.
本研究设计了一种通过光学触发器驱动的脉冲高压空心阴极电子束源，具有结构简单、成本低廉、易于触发等特点。为了验证新设计，实验研究了脉冲高压驱动下空心阴极的放电特性和电子束特性，并分别通过放电特性和波形细节分析进行了讨论。验证实验表明，脉冲高压电源显著提高了放电的频率和稳定性，为实现高频高能电子束源提供了新的解决方案。高能电子束的峰值电流幅值从 6.2 A 增加到 79.6 A，这表明脉冲电源模式大大提高了电子束的性能。此外，增加电容对高电流、低能量电子束的影响比对高能量电子束的影响更大。
{"title":"A study of pulsed high voltage driven hollow-cathode electron beam sources through synchronous optical trigger","authors":"Weijie Huo, Weiguo He, Luofeng Han, Kangwu Zhu, Feng Wang","doi":"10.1088/2058-6272/ad113e","DOIUrl":"https://doi.org/10.1088/2058-6272/ad113e","url":null,"abstract":"In this study, a pulsed, high voltage driven hollow-cathode electron beam sources through an optical trigger is designed with characteristics of simple structure, low cost, and easy triggering. To validate the new design, the characteristics of hollow-cathode discharge and electron beam characterization under pulsed high voltage drive are studied experimentally and discussed by discharge characteristics and analyses of waveform details, respectively. The validation experiments indicate that the pulsed high voltage supply significantly improves the frequency and stability of the discharge, which provides a new solution for the realization of a high-frequency, high-energy electron beam source. The peak current amplitude in the high-energy electron beam increases from 6.2 A to 79.6 A, which indicates the pulsed power mode significantly improves the electron beam performance. Besides, increasing the capacitance significantly affects the high-current, lower-energy electron beam more than the highenergy electron beam.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139207545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-28DOI: 10.1088/2058-6272/ad1044
L. Nie, Dawei Liu, He Cheng, Feng Zhao, Xinpei Lu
Plasma-enhanced transdermal drug delivery (TDD) presents advantages over traditional methods, including painless application, minimal skin damage, and rapid recovery of permeability. To harness its clinical potential, factors related to plasma's unique properties, such as reactive species and electric fields, must be carefully considered.This review provides a concise summary of conventional TDD methods and subsequently offers a comprehensive examination of the current state-of-the-art in plasma-enhanced TDD. This includes an analysis of the impact of plasma on HaCaT human keratinocyte cells, ex vivo/in vivo studies, and clinical research on plasma-assisted TDD. Moreover, the review explores the effects of plasma on skin physical characteristics such as microhole formation, transepidermal water loss (TEWL), molecular structure of the stratum corneum (SC), and skin resistance. Additionally, it discusses the involvement of various reactive agents in plasma-enhanced TDD, encompassing electric fields, charged particles, UV/VUV radiation, heat, and reactive species. Lastly, the review briefly addresses the temporal behavior of the skin after plasma treatment, safety considerations, and potential risks associated with plasma-enhanced TDD.
{"title":"The state-of-the-art of atmospheric pressure plasma for transdermal drug delivery","authors":"L. Nie, Dawei Liu, He Cheng, Feng Zhao, Xinpei Lu","doi":"10.1088/2058-6272/ad1044","DOIUrl":"https://doi.org/10.1088/2058-6272/ad1044","url":null,"abstract":"Plasma-enhanced transdermal drug delivery (TDD) presents advantages over traditional methods, including painless application, minimal skin damage, and rapid recovery of permeability. To harness its clinical potential, factors related to plasma's unique properties, such as reactive species and electric fields, must be carefully considered.This review provides a concise summary of conventional TDD methods and subsequently offers a comprehensive examination of the current state-of-the-art in plasma-enhanced TDD. This includes an analysis of the impact of plasma on HaCaT human keratinocyte cells, ex vivo/in vivo studies, and clinical research on plasma-assisted TDD. Moreover, the review explores the effects of plasma on skin physical characteristics such as microhole formation, transepidermal water loss (TEWL), molecular structure of the stratum corneum (SC), and skin resistance. Additionally, it discusses the involvement of various reactive agents in plasma-enhanced TDD, encompassing electric fields, charged particles, UV/VUV radiation, heat, and reactive species. Lastly, the review briefly addresses the temporal behavior of the skin after plasma treatment, safety considerations, and potential risks associated with plasma-enhanced TDD.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139222452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-28DOI: 10.1088/2058-6272/ad1045
Junwei Jia, Zhifeng Liu, Congyuan Pan, Huaqin Xue
The precise measurement of Al, Mg, Ca, and Zn composition in copper slag is crucial for effective process control of copper pyrometallurgy. In this study, a remote laser-induced breakdown spectroscopy (LIBS) system was utilized for the spectral analysis of copper slag samples at a distance of 2.5 m. The composition of copper slag was then analyzed using both the calibration curve (CC) method and the partial least squares regression (PLSR) analysis method based on the characteristic spectral intensity ratio. The performance of the two analysis methods was gauged through the determination coefficient (R2), average relative error (ARE), root mean square error of calibration (RMSEC), and root mean square error of prediction (RMSEP). The results demonstrate that the PLSR method significantly improved both R2 for the calibration and test sets while reducing ARE, RMSEC, and RMSEP by 50% compared to the CC method. The results suggest that the combination of LIBS and PLSR is a viable approach for effectively detecting the elemental concentration in copper slag and holds potential for online detection of the elemental composition of high-temperature molten copper slag.
{"title":"Detection of Al, Mg, Ca, and Zn in copper slag by LIBS combined with calibration curve and PLSR methods","authors":"Junwei Jia, Zhifeng Liu, Congyuan Pan, Huaqin Xue","doi":"10.1088/2058-6272/ad1045","DOIUrl":"https://doi.org/10.1088/2058-6272/ad1045","url":null,"abstract":"The precise measurement of Al, Mg, Ca, and Zn composition in copper slag is crucial for effective process control of copper pyrometallurgy. In this study, a remote laser-induced breakdown spectroscopy (LIBS) system was utilized for the spectral analysis of copper slag samples at a distance of 2.5 m. The composition of copper slag was then analyzed using both the calibration curve (CC) method and the partial least squares regression (PLSR) analysis method based on the characteristic spectral intensity ratio. The performance of the two analysis methods was gauged through the determination coefficient (R2), average relative error (ARE), root mean square error of calibration (RMSEC), and root mean square error of prediction (RMSEP). The results demonstrate that the PLSR method significantly improved both R2 for the calibration and test sets while reducing ARE, RMSEC, and RMSEP by 50% compared to the CC method. The results suggest that the combination of LIBS and PLSR is a viable approach for effectively detecting the elemental concentration in copper slag and holds potential for online detection of the elemental composition of high-temperature molten copper slag.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139218949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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