Pub Date : 2023-12-25DOI: 10.1088/1674-1056/ad188d
Tingting Zhang, Y. Gong, Ziqian Lu, Feng Xu
The thermal-elastic martensitic transformation from high-temperature Ni2In-type hexagonal structure to low-temperature TiNiSi-type orthorhombic structure has been widely observed in MnMX (M=Ni or Co, and X=Ge or Si) alloys. However, the answer to how the orthorhombic martensite nucleates and grows within the hexagonal parent is still unclear. This paper investigates the hexagonal-orthorhombic martensitic transformation in a Co and Ge co-substituted MnNiSi. One can find some orthorhombic laths embedded in the hexagonal parent at a temperature above the martensitic transformation start temperature (M s). With the cooling of the sample to M s, the laths extend broader, indicating that the martensitic transformation starts from these pre-existing orthorhombic laths. Microstructure observation suggests that these pre-existing orthorhombic laths are not originated from the hexagonal-orthorhombic martensitic transformation because of the difference in atomic occupations of doping elements in the hexagonal parent and pre-existing orthorhombic laths. The phenomenological crystallographic theory and experimental investigations prove that the pre-existing orthorhombic lath and generated orthorhombic martensite have the same crystallography relationship to the hexagonal parent. Therefore, the orthorhombic martensite can take these pre-existing laths as embryos and grow up. This work implies that the martensitic transformation in MnNiSi1-x(CoNiGe)x alloy is initiated by orthorhombic embryos.
在 MnMX（M=Ni 或 Co，X=Ge 或 Si）合金中广泛观察到从高温 Ni2In 型六方结构到低温 TiNiSi- 型正方体结构的热弹性马氏体转变。然而，正方体马氏体如何在六方母体中成核和生长的答案仍不清楚。本文研究了 Co 和 Ge 共取代锰镍硅合金中的六方-正方马氏体转变。在温度高于马氏体转变起始温度（M s）时，可以发现一些正方体板条嵌入六方母体中。当样品冷却到 M s 时，板条延伸得更宽，这表明马氏体转变是从这些预先存在的正方体板条开始的。显微结构观察表明，这些预先存在的正菱形板条并非源于六方-正菱形马氏体转变，因为六方母体和预先存在的正菱形板条中掺杂元素的原子占位不同。现象晶体学理论和实验研究证明，原有的正方体板条和生成的正方体马氏体与六方母体具有相同的晶体学关系。因此，正方马氏体可以将这些预先存在的板条作为胚胎并成长起来。这项研究表明，MnNiSi1-x(CoNiGe)x 合金中的马氏体转变是由正方体胚开始的。
{"title":"The hexagonal-orthorhombic martensitic transformation in MnNiSi1-x(CoNiGe)x alloy: being triggered by pre-existing orthorhombic embryos","authors":"Tingting Zhang, Y. Gong, Ziqian Lu, Feng Xu","doi":"10.1088/1674-1056/ad188d","DOIUrl":"https://doi.org/10.1088/1674-1056/ad188d","url":null,"abstract":"The thermal-elastic martensitic transformation from high-temperature Ni2In-type hexagonal structure to low-temperature TiNiSi-type orthorhombic structure has been widely observed in MnMX (M=Ni or Co, and X=Ge or Si) alloys. However, the answer to how the orthorhombic martensite nucleates and grows within the hexagonal parent is still unclear. This paper investigates the hexagonal-orthorhombic martensitic transformation in a Co and Ge co-substituted MnNiSi. One can find some orthorhombic laths embedded in the hexagonal parent at a temperature above the martensitic transformation start temperature (M s). With the cooling of the sample to M s, the laths extend broader, indicating that the martensitic transformation starts from these pre-existing orthorhombic laths. Microstructure observation suggests that these pre-existing orthorhombic laths are not originated from the hexagonal-orthorhombic martensitic transformation because of the difference in atomic occupations of doping elements in the hexagonal parent and pre-existing orthorhombic laths. The phenomenological crystallographic theory and experimental investigations prove that the pre-existing orthorhombic lath and generated orthorhombic martensite have the same crystallography relationship to the hexagonal parent. Therefore, the orthorhombic martensite can take these pre-existing laths as embryos and grow up. This work implies that the martensitic transformation in MnNiSi1-x(CoNiGe)x alloy is initiated by orthorhombic embryos.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"27 3","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139158033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-12-25DOI: 10.1088/1674-1056/ad188e
Bin Sun, Yangfan He, Chenhao Pan, Sijie Fan, Du Wang, Shaoyi Wang, Zongqing Zhao
The use of positron beam flow has a wide range of applications, and in this paper, we present the first on-chip positron accelerator based on dielectric laser acceleration. This innovative approach significantly reduces the physical dimensions of the positron acceleration apparatus, enhancing its feasibility for diverse applications. By utilizing a stacked acceleration structure and far-infrared laser technology, we were able to achieve a seven-stage acceleration structure that surpassed the distance and energy gain of previous dielectric laser acceleration methods. Additionally, we were able to compress the positron beam to an ultrafast sub-femtosecond scale during the acceleration process, compared with traditional methods, the positron beam is compressed to a greater extent. We also demonstrated the robustness of the stacked acceleration structure through the successful acceleration of the positron beam.
{"title":"On chip ultrafast stackable dielectric laser positron accelerator","authors":"Bin Sun, Yangfan He, Chenhao Pan, Sijie Fan, Du Wang, Shaoyi Wang, Zongqing Zhao","doi":"10.1088/1674-1056/ad188e","DOIUrl":"https://doi.org/10.1088/1674-1056/ad188e","url":null,"abstract":"The use of positron beam flow has a wide range of applications, and in this paper, we present the first on-chip positron accelerator based on dielectric laser acceleration. This innovative approach significantly reduces the physical dimensions of the positron acceleration apparatus, enhancing its feasibility for diverse applications. By utilizing a stacked acceleration structure and far-infrared laser technology, we were able to achieve a seven-stage acceleration structure that surpassed the distance and energy gain of previous dielectric laser acceleration methods. Additionally, we were able to compress the positron beam to an ultrafast sub-femtosecond scale during the acceleration process, compared with traditional methods, the positron beam is compressed to a greater extent. We also demonstrated the robustness of the stacked acceleration structure through the successful acceleration of the positron beam.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"8 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139159479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-12-22DOI: 10.1088/1674-1056/ad1820
Ao Xu, Pingping Gan, Yuanjie Shi, Lei Chen
The characteristics of the extracted ion current have a significant impact on the design and testing of ion source performance. In this paper, 2D3V particle in cell (2D3V PIC) method is utilized to simulate plasma motion and ion extraction characteristics under various initial plasma velocity distributions and extraction voltages in a Cartesian coordinate system. The plasma density is in the order of 1015 m-3~1016 m-3 and the extraction voltage is in the order of 100 V~1000V. The study investigates the impact of various extraction voltages on the velocity and density distributions of electrons and positive ions, and analyzes the influence of different initial plasma velocity distributions on the extraction current. The simulation results revealed that the main reason for the variation of extraction current is the space charge force formed by the relative aggregation of positive and negative net charges. This lays the foundation for a deeper understanding of extraction beam characteristics.
{"title":"Influence of extraction voltage on electrons and ions behavior characteristics","authors":"Ao Xu, Pingping Gan, Yuanjie Shi, Lei Chen","doi":"10.1088/1674-1056/ad1820","DOIUrl":"https://doi.org/10.1088/1674-1056/ad1820","url":null,"abstract":"\u0000 The characteristics of the extracted ion current have a significant impact on the design and testing of ion source performance. In this paper, 2D3V particle in cell (2D3V PIC) method is utilized to simulate plasma motion and ion extraction characteristics under various initial plasma velocity distributions and extraction voltages in a Cartesian coordinate system. The plasma density is in the order of 1015 m-3~1016 m-3 and the extraction voltage is in the order of 100 V~1000V. The study investigates the impact of various extraction voltages on the velocity and density distributions of electrons and positive ions, and analyzes the influence of different initial plasma velocity distributions on the extraction current. The simulation results revealed that the main reason for the variation of extraction current is the space charge force formed by the relative aggregation of positive and negative net charges. This lays the foundation for a deeper understanding of extraction beam characteristics.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"52 22","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138946261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-12-22DOI: 10.1088/1674-1056/ad181e
Qian Zhang, Xiankun Yao, Heng Dong
We show that the nonlinear stage of the dual-wavelength pumped modulation instability (MI) in nonlinear Schrödinger equation (NLSE) can be effectively analyzed by mode truncation methods. The resulting complicated heteroclinic structure of instability unveils all possible dynamic trajectories of nonlinear waves. Significantly, the latticed-Fermi-Pasta-Ulam recurrences on the modulated-wave background in NLSE are also investigated and their dynamic trajectories ran along the Hamiltonian contours of the heteroclinic structure. It is demonstrated that there is much richer dynamic behavior, in contrast to the nonlinear waves reported before. This novel nonlinear wave promises to inject new vitality into the study of MI.
我们的研究表明，非线性薛定谔方程（NLSE）中双波长泵浦调制不稳定性（MI）的非线性阶段可以通过模截断方法进行有效分析。由此产生的复杂异面不稳定性结构揭示了非线性波所有可能的动态轨迹。值得注意的是，我们还研究了 NLSE 中调制波背景上的晶格-费米-帕斯塔-乌拉姆递归，并沿着异链结构的哈密顿轮廓分析了它们的动态轨迹。结果表明，与之前报道的非线性波相比，非线性波的动态行为要丰富得多。这种新型非线性波有望为 MI 研究注入新的活力。
{"title":"Dual-wavelength pumped latticed Fermi-Pasta-Ulam recurrences in Nonlinear Schrödinger Equation","authors":"Qian Zhang, Xiankun Yao, Heng Dong","doi":"10.1088/1674-1056/ad181e","DOIUrl":"https://doi.org/10.1088/1674-1056/ad181e","url":null,"abstract":"\u0000 We show that the nonlinear stage of the dual-wavelength pumped modulation instability (MI) in nonlinear Schrödinger equation (NLSE) can be effectively analyzed by mode truncation methods. The resulting complicated heteroclinic structure of instability unveils all possible dynamic trajectories of nonlinear waves. Significantly, the latticed-Fermi-Pasta-Ulam recurrences on the modulated-wave background in NLSE are also investigated and their dynamic trajectories ran along the Hamiltonian contours of the heteroclinic structure. It is demonstrated that there is much richer dynamic behavior, in contrast to the nonlinear waves reported before. This novel nonlinear wave promises to inject new vitality into the study of MI.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"14 7","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138947307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-12-22DOI: 10.1088/1674-1056/ad1823
Fu Yang, Zhenxing Bo, Yao Huang, Yutian Wang, Boyang Sun, Zhen Lu, Baoan Sun, Yanhui Liu, Weihua Wang, Mingxiang Pan
Melt treatment is well known to have an important influence on the properties of metallic glasses (MGs). However, for the MGs quenched from different melt temperatures with a quartz tube, the underlying physical origin responsible for the variation of properties remains poorly understood. In the present work, we systematically studied the influence of melt treatment on the thermal properties of a Zr50Cu36Al14 glass-forming alloy and unveiled the microscopic origins. Specifically, we quenched the melt at different temperatures ranging from 1.1T l to 1.5T l (T l is the liquidus temperature) to obtain melt-spun MG ribbons and investigated the variation of thermal properties of the MGs upon heating. We found that glass transition temperature, T g , increases by as much as 36 K, and the supercooled liquid region disappears in the curve of differential scanning calorimetry when the melt is quenched at a high temperature up to 1.5T l . The careful chemical analyses indicate that the change in glass transition behavior originates from the incorporation of oxygen and silicon in the molten alloys. The incorporated oxygen and silicon can both enhance the atomic interactions between atoms, which renders the cooperative rearrangements of atoms difficult, and thus enhance the kinetic stability of the MGs.
众所周知，熔融处理对金属玻璃（MGs）的特性有重要影响。然而，对于用石英管从不同熔体温度淬火的金属玻璃而言，导致其性能变化的基本物理原因仍然鲜为人知。在本研究中，我们系统地研究了熔体处理对 Zr50Cu36Al14 玻璃成形合金热性能的影响，并揭示了其微观根源。具体来说，我们在 1.1T l 至 1.5T l（T l 为液相温度）的不同温度下对熔体进行淬火，以获得熔融纺丝的 MG 带，并研究了加热时 MG 热性能的变化。我们发现，当熔体在高达 1.5T l 的高温下淬火时，玻璃化转变温度 T g 上升了 36 K 之多，并且在差示扫描量热曲线上过冷液体区域消失了。仔细的化学分析表明，玻璃化转变行为的变化源于熔融合金中氧和硅的加入。掺入的氧和硅都能增强原子间的相互作用，使原子间的协同重排变得困难，从而增强了 MGs 的动力学稳定性。
{"title":"The effect of overheating-induced minor addition on Zr-based metallic glasses","authors":"Fu Yang, Zhenxing Bo, Yao Huang, Yutian Wang, Boyang Sun, Zhen Lu, Baoan Sun, Yanhui Liu, Weihua Wang, Mingxiang Pan","doi":"10.1088/1674-1056/ad1823","DOIUrl":"https://doi.org/10.1088/1674-1056/ad1823","url":null,"abstract":"\u0000 Melt treatment is well known to have an important influence on the properties of metallic glasses (MGs). However, for the MGs quenched from different melt temperatures with a quartz tube, the underlying physical origin responsible for the variation of properties remains poorly understood. In the present work, we systematically studied the influence of melt treatment on the thermal properties of a Zr50Cu36Al14 glass-forming alloy and unveiled the microscopic origins. Specifically, we quenched the melt at different temperatures ranging from 1.1T\u0000 \u0000 l\u0000 to 1.5T\u0000 \u0000 l\u0000 (T\u0000 \u0000 l\u0000 is the liquidus temperature) to obtain melt-spun MG ribbons and investigated the variation of thermal properties of the MGs upon heating. We found that glass transition temperature, T\u0000 \u0000 g\u0000 , increases by as much as 36 K, and the supercooled liquid region disappears in the curve of differential scanning calorimetry when the melt is quenched at a high temperature up to 1.5T\u0000 \u0000 l\u0000 . The careful chemical analyses indicate that the change in glass transition behavior originates from the incorporation of oxygen and silicon in the molten alloys. The incorporated oxygen and silicon can both enhance the atomic interactions between atoms, which renders the cooperative rearrangements of atoms difficult, and thus enhance the kinetic stability of the MGs.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"61 22","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138945656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-12-22DOI: 10.1088/1674-1056/ad1822
Qiao-Hong Han, Man Jia
Integrable systems play a crucial role in physics and mathematics. In particular, the traditional (1 + 1)-dimensional and (2 + 1)-dimensional integrable systems have received significant attention due to the rarity of integrable systems in higher dimensions. Recent studies have shown that abundant higher dimensional integrable systems can be constructed from (1 + 1)-dimensional integrable systems by using a deformation algorithm. In this manuscript, a new (2 + 1)-dimensional Chen-Lee-Liu (C-L-L) equation is established using the deformation algorithm from the (1+1)-dimensional C-L-L equation. The new system is integrable with its Lax pair obtained by applying the deformation algorithm to that of the (1 + 1)-dimension. It is challenging to obtain the exact solutions for the new integrable system because the new system combines both the original C-L-L equation and its reciprocal transformation. The traveling wave solutions are derived in implicit function expression and some asymmetry peakon solutions are found.
{"title":"Higher Dimensional Chen-Lee-Liu Equation and Asymmetric Peakon Soliton","authors":"Qiao-Hong Han, Man Jia","doi":"10.1088/1674-1056/ad1822","DOIUrl":"https://doi.org/10.1088/1674-1056/ad1822","url":null,"abstract":"\u0000 Integrable systems play a crucial role in physics and mathematics. In particular, the traditional (1 + 1)-dimensional and (2 + 1)-dimensional integrable systems have received significant attention due to the rarity of integrable systems in higher dimensions. Recent studies have shown that abundant higher dimensional integrable systems can be constructed from (1 + 1)-dimensional integrable systems by using a deformation algorithm. In this manuscript, a new (2 + 1)-dimensional Chen-Lee-Liu (C-L-L) equation is established using the deformation algorithm from the (1+1)-dimensional C-L-L equation. The new system is integrable with its Lax pair obtained by applying the deformation algorithm to that of the (1 + 1)-dimension. It is challenging to obtain the exact solutions for the new integrable system because the new system combines both the original C-L-L equation and its reciprocal transformation. The traveling wave solutions are derived in implicit function expression and some asymmetry peakon solutions are found.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"5 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138944636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-12-22DOI: 10.1088/1674-1056/ad181d
Yiwei Huang, Shuqi Xu, Shimin Cai, Linyuan Lü
With the rapid growth of manuscript submissions, finding eligible reviewers for every submission has become a heavy task. Recommender systems are powerful tools developed in computer science and information science to deal with this problem. However, most existing approaches resort to text mining techniques to match manuscripts with potential reviewers, which require high-quality textual information to perform well. In this paper, we propose a reviewer recommendation algorithm based on a network diffusion process on a scholar-paper multilayer network, with no requirement for textual information. The network incorporates the relationship of scholar-paper pairs, the collaboration among scholars, and the bibliographic coupling among papers. Experimental results show that our proposed algorithm outperforms other state-of-the-art recommendation methods that use graph random walk and matrix factorization and methods that use machine learning and natural language processing, with improvements of over 7.62% in Recall, 5.66% in Hit Rate, and 47.53% in Ranking Score. Our work sheds light on the effectiveness of multilayer network diffusion-based methods in the reviewer recommendation problem, which will help to facilitate the peer-review process and promote information retrieval research in other practical scenes.
{"title":"A multilayer network diffusion-based model for reviewer recommendation","authors":"Yiwei Huang, Shuqi Xu, Shimin Cai, Linyuan Lü","doi":"10.1088/1674-1056/ad181d","DOIUrl":"https://doi.org/10.1088/1674-1056/ad181d","url":null,"abstract":"\u0000 With the rapid growth of manuscript submissions, finding eligible reviewers for every submission has become a heavy task. Recommender systems are powerful tools developed in computer science and information science to deal with this problem. However, most existing approaches resort to text mining techniques to match manuscripts with potential reviewers, which require high-quality textual information to perform well. In this paper, we propose a reviewer recommendation algorithm based on a network diffusion process on a scholar-paper multilayer network, with no requirement for textual information. The network incorporates the relationship of scholar-paper pairs, the collaboration among scholars, and the bibliographic coupling among papers. Experimental results show that our proposed algorithm outperforms other state-of-the-art recommendation methods that use graph random walk and matrix factorization and methods that use machine learning and natural language processing, with improvements of over 7.62% in Recall, 5.66% in Hit Rate, and 47.53% in Ranking Score. Our work sheds light on the effectiveness of multilayer network diffusion-based methods in the reviewer recommendation problem, which will help to facilitate the peer-review process and promote information retrieval research in other practical scenes.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"17 17","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138947019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-12-22DOI: 10.1088/1674-1056/ad1821
Jian-quan Li, Hai-jie Ma, Wen-qi Lu
A novel emissive probe consisting of an oxide cathode coating is developed to achieve the low operating temperature and long service life of the emissive probe. Compared with the traditional tungsten emissive probe, the properties of the novel emissive probe are investigated in detail, including the operating temperature, the electron emission capability and the plasma potential measurement. Studies of the operating temperature and the electron emission capability show that the tungsten emissive probe usually works at a temperature of 1800-2200 K, while the oxide cathode emissive probe can function at about 1200-1400 K. In addition, the plasma potential measurements using the oxide cathode emissive probe with different techniques have also been accomplished in MW-ECR plasmas with different discharge powers. It is found that the reliable plasma potential can be obtained by using the improved inflection point (IIP) method and the hot probe with zero emission limit (HP-ZEL) method, while the floating point (FP) method is invalid for the oxide cathode emissive probe.
{"title":"Plasma potential measurements using an emissive probe made of oxide cathode","authors":"Jian-quan Li, Hai-jie Ma, Wen-qi Lu","doi":"10.1088/1674-1056/ad1821","DOIUrl":"https://doi.org/10.1088/1674-1056/ad1821","url":null,"abstract":"\u0000 A novel emissive probe consisting of an oxide cathode coating is developed to achieve the low operating temperature and long service life of the emissive probe. Compared with the traditional tungsten emissive probe, the properties of the novel emissive probe are investigated in detail, including the operating temperature, the electron emission capability and the plasma potential measurement. Studies of the operating temperature and the electron emission capability show that the tungsten emissive probe usually works at a temperature of 1800-2200 K, while the oxide cathode emissive probe can function at about 1200-1400 K. In addition, the plasma potential measurements using the oxide cathode emissive probe with different techniques have also been accomplished in MW-ECR plasmas with different discharge powers. It is found that the reliable plasma potential can be obtained by using the improved inflection point (IIP) method and the hot probe with zero emission limit (HP-ZEL) method, while the floating point (FP) method is invalid for the oxide cathode emissive probe.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"8 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138944533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-12-22DOI: 10.1088/1674-1056/ad181f
Long Xu, Xinrui Yao, Yang Shen
In this article, we present a dynamic model of cavitation bubbles in a cluster that considers the effect of evaporation, condensation, and bubble to bubble interactions. Under different ultrasound conditions, we examine how the dynamics of cavitation bubbles are affected by several factors, such as the location of the bubbles, the ambient radius, and the number of bubbles. This investigation includes analyzing alterations in bubble radius, energy, temperature, pressure, and the quantity of vapor molecules. Our findings reveal that bubble-bubble interactions can restrict the expansion of bubbles, reduce the exchange of energy and vapor molecules, and diminish the maximum internal temperature and pressure upon bursting. The ambient radius of bubbles can influence the intensity of their oscillations, with clusters comprising smaller bubbles creating optimal conditions for generating high-temperature and high-pressure regions. Moreover, an increase in the number of bubbles can further inhibit cavitation activities. The frequency, pressure and waveform of the driving wave also have a significant impact on cavitation activities, with rectangular waves enhancing and triangular waves weakening the cavitation of bubbles in the cluster. These results provide a theoretical basis for understanding the dynamics of cavitation bubbles within a bubble cluster, and the factors that affect their behavior.
{"title":"Dynamic Modeling of Cavitation Bubble Clusters: Effects of Evaporation, Condensation, and Bubble-Bubble Interaction","authors":"Long Xu, Xinrui Yao, Yang Shen","doi":"10.1088/1674-1056/ad181f","DOIUrl":"https://doi.org/10.1088/1674-1056/ad181f","url":null,"abstract":"\u0000 In this article, we present a dynamic model of cavitation bubbles in a cluster that considers the effect of evaporation, condensation, and bubble to bubble interactions. Under different ultrasound conditions, we examine how the dynamics of cavitation bubbles are affected by several factors, such as the location of the bubbles, the ambient radius, and the number of bubbles. This investigation includes analyzing alterations in bubble radius, energy, temperature, pressure, and the quantity of vapor molecules. Our findings reveal that bubble-bubble interactions can restrict the expansion of bubbles, reduce the exchange of energy and vapor molecules, and diminish the maximum internal temperature and pressure upon bursting. The ambient radius of bubbles can influence the intensity of their oscillations, with clusters comprising smaller bubbles creating optimal conditions for generating high-temperature and high-pressure regions. Moreover, an increase in the number of bubbles can further inhibit cavitation activities. The frequency, pressure and waveform of the driving wave also have a significant impact on cavitation activities, with rectangular waves enhancing and triangular waves weakening the cavitation of bubbles in the cluster. These results provide a theoretical basis for understanding the dynamics of cavitation bubbles within a bubble cluster, and the factors that affect their behavior.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"2 11","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138944834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-12-20DOI: 10.1088/1674-1056/ad174a
Yanan Dai
Exploring the realms of physics that extend beyond thermal equilibrium has emerged as a crucial branch of condensed matter physics research. It aims to unravel the intricate processes involving the excitations, interactions, and annihilations of quasi- and many-body particles, and ultimately to achieve the manipulation and engineering of exotic non-equilibrium quantum phases on the ultrasmall and ultrafast spatiotemporal scales. Given the inherent complexities arising from many-body dynamics, it therefore seeks for a technique that has efficient and diverse detection degrees of freedoms to study the underlying physics. By combining high-power femtosecond lasers with real- or momentum-space photoemission electron microscopy (PEEM), imaging excited state phenomena from multiple perspectives, including time, real space, energy, momentum, and spin, can be conveniently achieved, making it a unique technique in studying physics out of equilibrium. In this context, we overview the working principle and technical advances of the PEEM apparatus and the related laser systems, and survey key excited-state phenomena probed through this surface-sensitive methodology, including the ultrafast dynamics of electrons, excitons, plasmons, and spins etc., in materials ranging from bulk and nano-structured metals and semiconductors to low dimensional quantum materials. Through this review, one can further envision that time-resolved PEEM will open new avenues for investigating a variety of classical and quantum phenomena in a multidimensional parameter space, offering unprecedented and comprehensive insights to important questions in the field of condensed matter physics.
{"title":"Ultrafast Photoemission Electron Microscopy: A multidimensional probe of nonequilibrium physics","authors":"Yanan Dai","doi":"10.1088/1674-1056/ad174a","DOIUrl":"https://doi.org/10.1088/1674-1056/ad174a","url":null,"abstract":"Exploring the realms of physics that extend beyond thermal equilibrium has emerged as a crucial branch of condensed matter physics research. It aims to unravel the intricate processes involving the excitations, interactions, and annihilations of quasi- and many-body particles, and ultimately to achieve the manipulation and engineering of exotic non-equilibrium quantum phases on the ultrasmall and ultrafast spatiotemporal scales. Given the inherent complexities arising from many-body dynamics, it therefore seeks for a technique that has efficient and diverse detection degrees of freedoms to study the underlying physics. By combining high-power femtosecond lasers with real- or momentum-space photoemission electron microscopy (PEEM), imaging excited state phenomena from multiple perspectives, including time, real space, energy, momentum, and spin, can be conveniently achieved, making it a unique technique in studying physics out of equilibrium. In this context, we overview the working principle and technical advances of the PEEM apparatus and the related laser systems, and survey key excited-state phenomena probed through this surface-sensitive methodology, including the ultrafast dynamics of electrons, excitons, plasmons, and spins etc., in materials ranging from bulk and nano-structured metals and semiconductors to low dimensional quantum materials. Through this review, one can further envision that time-resolved PEEM will open new avenues for investigating a variety of classical and quantum phenomena in a multidimensional parameter space, offering unprecedented and comprehensive insights to important questions in the field of condensed matter physics.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"16 11","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139168428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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