Pub Date : 2006-09-01DOI: 10.1109/DEIV.2006.357243
O. Yamamoto, H. Hayashi, T. Satoh, S. Hamada, T. Kobayashi, H. Omura, H. Morii
In our previous studies, with a comparatively short cylindrical insulator of 10 mm length, we have found that the charging process due to ac voltage excitation in vacuum is characterized by three different states; initiation, quasi-stable state and stable state. In all of the states, the insulator surface acquires positive charge irrespective of applied voltage amplitude or phase. Also, we have reported that the magnitude of the charge decreases with the roughness of insulator, and that this results in the improvement of surface insulation strength. To apply the above results for practical insulators used for vacuum valves of VCBs, we have investigated the characteristics for a longer insulator up to 50 mm made of borosilicate (Pyrexreg). As a result, we have confirmed that the charging process is basically the same as that observed in the previous studies. We have also confirmed the effectiveness of roughening the surface on reducing the charge magnitude and increasing the flashover voltage
{"title":"Flashover and Charging Characteristics of a Long Solid Insulator Exposed to ac Voltage in Vacuum","authors":"O. Yamamoto, H. Hayashi, T. Satoh, S. Hamada, T. Kobayashi, H. Omura, H. Morii","doi":"10.1109/DEIV.2006.357243","DOIUrl":"https://doi.org/10.1109/DEIV.2006.357243","url":null,"abstract":"In our previous studies, with a comparatively short cylindrical insulator of 10 mm length, we have found that the charging process due to ac voltage excitation in vacuum is characterized by three different states; initiation, quasi-stable state and stable state. In all of the states, the insulator surface acquires positive charge irrespective of applied voltage amplitude or phase. Also, we have reported that the magnitude of the charge decreases with the roughness of insulator, and that this results in the improvement of surface insulation strength. To apply the above results for practical insulators used for vacuum valves of VCBs, we have investigated the characteristics for a longer insulator up to 50 mm made of borosilicate (Pyrexreg). As a result, we have confirmed that the charging process is basically the same as that observed in the previous studies. We have also confirmed the effectiveness of roughening the surface on reducing the charge magnitude and increasing the flashover voltage","PeriodicalId":369861,"journal":{"name":"2006 International Symposium on Discharges and Electrical Insulation in Vacuum","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116189806","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}
M. Ohnishi, H. Nozaki, H. Osawa, K. Minaki, K. Kitajima, K. Yokota
A negative potential is applied to an object in plasma consisting of methane or acetylene in order to coat a solid thin film such as DLC (diamond-like-carbon) on a material surface. The method is called plasma-based ion implantation (PBII). Since mechanical objects commonly possess complex shapes, it may be difficult to coat DLC on them in a uniform manner. This non-uniformity in thickness has been studied in many papers, and it has been reported that it is improved by applying a pulse potential repeatedly to the coated material. Using a scratch test, we studied the local adhesion of DLC coated by PBII to SUS304 thin plates attached at several places in a trench-shaped cathode. We found that the adhesion gets greater, in order, for the plates at the side, the bottom of the groove in a trench, and the top of a trench. In order to explain the results, further studies are required
{"title":"Local Adhesion of Diamond-Like Carbon Films Coated on Substrates in a Trench-shaped Cathode","authors":"M. Ohnishi, H. Nozaki, H. Osawa, K. Minaki, K. Kitajima, K. Yokota","doi":"10.3131/jvsj.50.328","DOIUrl":"https://doi.org/10.3131/jvsj.50.328","url":null,"abstract":"A negative potential is applied to an object in plasma consisting of methane or acetylene in order to coat a solid thin film such as DLC (diamond-like-carbon) on a material surface. The method is called plasma-based ion implantation (PBII). Since mechanical objects commonly possess complex shapes, it may be difficult to coat DLC on them in a uniform manner. This non-uniformity in thickness has been studied in many papers, and it has been reported that it is improved by applying a pulse potential repeatedly to the coated material. Using a scratch test, we studied the local adhesion of DLC coated by PBII to SUS304 thin plates attached at several places in a trench-shaped cathode. We found that the adhesion gets greater, in order, for the plates at the side, the bottom of the groove in a trench, and the top of a trench. In order to explain the results, further studies are required","PeriodicalId":369861,"journal":{"name":"2006 International Symposium on Discharges and Electrical Insulation in Vacuum","volume":"404 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123000337","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 : 2006-09-01DOI: 10.1109/DEIV.2006.357289
Zhiyuan Liu, Z. Wang, Jimei Wang
This paper introduces a new slot type axial magnetic field (AMF) contact. It has lower resistance compared with its counterpart conventional one by introducing a contact bridge that substitutes for stainless steel support in conventional contact. There is a gap between the contact bridge and contact plate. In close position, the contact bridge is pressed on contact plate by contact force and coil deformation. So current goes through the contact bridge to reach contact plate directly. In an interruption operation, the gap restores with contact force disappearing, which pushes current passing through coils of the slot type AMF contact. So the same AMF can be generated as a conventional one. As a result, short circuit current interruption tests showed that the interrupting capacity of the vacuum interrupter with new contacts was not less than that with conventional contacts. Resistance of vacuum interrupter with conventional contact is 10-12 muOmega at contact force 2000N. It decreased to 7muOmega with the new contact
{"title":"A New Slot Type Axial Magnetic Field Contact with Low Resistance","authors":"Zhiyuan Liu, Z. Wang, Jimei Wang","doi":"10.1109/DEIV.2006.357289","DOIUrl":"https://doi.org/10.1109/DEIV.2006.357289","url":null,"abstract":"This paper introduces a new slot type axial magnetic field (AMF) contact. It has lower resistance compared with its counterpart conventional one by introducing a contact bridge that substitutes for stainless steel support in conventional contact. There is a gap between the contact bridge and contact plate. In close position, the contact bridge is pressed on contact plate by contact force and coil deformation. So current goes through the contact bridge to reach contact plate directly. In an interruption operation, the gap restores with contact force disappearing, which pushes current passing through coils of the slot type AMF contact. So the same AMF can be generated as a conventional one. As a result, short circuit current interruption tests showed that the interrupting capacity of the vacuum interrupter with new contacts was not less than that with conventional contacts. Resistance of vacuum interrupter with conventional contact is 10-12 muOmega at contact force 2000N. It decreased to 7muOmega with the new contact","PeriodicalId":369861,"journal":{"name":"2006 International Symposium on Discharges and Electrical Insulation in Vacuum","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131265216","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 : 2006-09-01DOI: 10.1109/DEIV.2006.357350
Chunguang Hou, Jing Sun, Yundong Cao, Xiaoming Liu, Erzhi Wang
A novel permanent magnet actuator (PMA) for mining vacuum circuit breaker (VCB) is presented in this paper. Which is monostable, has two coils and able to break the VCB when the fault of low-voltage happened. And can detect the voltage variation in main circuit at each instant. When the fault of low-voltage happened, it can automatically break without additional detection and control of apparatus. Moreover, the different states and parameters of breaking and closing courses have been numerical computed and analyzed by adopting ANSOFT software. Based on the simulation results, the prototype is manufactured and assembled in the mining VCB. The feasibility and validity of the proposed PMA have been proved by testing results
{"title":"Design and Analyses on Permanent Magnet Actuator for Mining Vacuum Circuit Breaker","authors":"Chunguang Hou, Jing Sun, Yundong Cao, Xiaoming Liu, Erzhi Wang","doi":"10.1109/DEIV.2006.357350","DOIUrl":"https://doi.org/10.1109/DEIV.2006.357350","url":null,"abstract":"A novel permanent magnet actuator (PMA) for mining vacuum circuit breaker (VCB) is presented in this paper. Which is monostable, has two coils and able to break the VCB when the fault of low-voltage happened. And can detect the voltage variation in main circuit at each instant. When the fault of low-voltage happened, it can automatically break without additional detection and control of apparatus. Moreover, the different states and parameters of breaking and closing courses have been numerical computed and analyzed by adopting ANSOFT software. Based on the simulation results, the prototype is manufactured and assembled in the mining VCB. The feasibility and validity of the proposed PMA have been proved by testing results","PeriodicalId":369861,"journal":{"name":"2006 International Symposium on Discharges and Electrical Insulation in Vacuum","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131765021","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 : 2006-09-01DOI: 10.1109/DEIV.2006.357225
A. Batrakov, D.J. Johnson, S. Onischenko, D. Proskurovsky
The paper is devoted to study of mechanisms responsible on vacuum breakdown as a whole and the total voltage effect in particular. Experiments at dc and pulsed voltages were carried out. It has been shown that there is no manifestation of the total voltage effect at dc voltages up to 20 kV. The strong dependence of hold-off on anode temperature was recognized at dc voltages while pulsed hold-off turned out to be almost the same with heating electrodes. This gives a basis to consider gas desorption as an insufficient factor in initiation of pulsed breakdown. An attempt to enhance hold-off with electrostatic removing of loosely bound particles with assistance of electron flow from a thermionic cathode was undertaken in the work. The approach tuned out to be ineffective
{"title":"Cathode and Anode Phenomena at Initiation of Pulsed Vacuum Breakdown","authors":"A. Batrakov, D.J. Johnson, S. Onischenko, D. Proskurovsky","doi":"10.1109/DEIV.2006.357225","DOIUrl":"https://doi.org/10.1109/DEIV.2006.357225","url":null,"abstract":"The paper is devoted to study of mechanisms responsible on vacuum breakdown as a whole and the total voltage effect in particular. Experiments at dc and pulsed voltages were carried out. It has been shown that there is no manifestation of the total voltage effect at dc voltages up to 20 kV. The strong dependence of hold-off on anode temperature was recognized at dc voltages while pulsed hold-off turned out to be almost the same with heating electrodes. This gives a basis to consider gas desorption as an insufficient factor in initiation of pulsed breakdown. An attempt to enhance hold-off with electrostatic removing of loosely bound particles with assistance of electron flow from a thermionic cathode was undertaken in the work. The approach tuned out to be ineffective","PeriodicalId":369861,"journal":{"name":"2006 International Symposium on Discharges and Electrical Insulation in Vacuum","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133436215","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 : 2006-09-01DOI: 10.1109/DEIV.2006.357219
Y. Korolev, O. B. Frants, V. G. Geyman, R. V. Ivashov, V. N. Landl, I. A. Shemyakin
In this paper the electric strength recovery process in the pseudospark switch is investigated. The reasons which lead to pulse repetition rate limitation are analyzed. The electric schemes for frequency operation increasing are investigated
本文研究了假火花开关的电强度恢复过程。分析了造成脉冲重复率限制的原因。研究了提高运行频率的电气方案
{"title":"Investigation of the Electric Strength Recovery Process in the Pseudospark Switch with a High Pulse Repetition Rate","authors":"Y. Korolev, O. B. Frants, V. G. Geyman, R. V. Ivashov, V. N. Landl, I. A. Shemyakin","doi":"10.1109/DEIV.2006.357219","DOIUrl":"https://doi.org/10.1109/DEIV.2006.357219","url":null,"abstract":"In this paper the electric strength recovery process in the pseudospark switch is investigated. The reasons which lead to pulse repetition rate limitation are analyzed. The electric schemes for frequency operation increasing are investigated","PeriodicalId":369861,"journal":{"name":"2006 International Symposium on Discharges and Electrical Insulation in Vacuum","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133625880","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 : 2006-09-01DOI: 10.1109/DEIV.2006.357356
J. Langner, M. Sadowski, P. Strzyzewski, R. Mirowski, J. Witkowski, S. Tazzari, L. Catani, A. Cianchi, J. Lorkiewicz, Roberto Russo, T. Paryjczak, J. Rogowski, J. Sekutowicz
The paper reports on recent progress in the application of the UHV arc technology, which was proposed as an alternative solution for the deposition of thin superconducting films of pure niobium (Nb) upon the inner surfaces of RF cavities designed for particle accelerators. There are presented new experimental studies aimed at the deposition of superconducting films of pure niobium (Nb) and lead (Pb) needed for the modern accelerator technology. The main experimental results and characteristics of arc-deposited thin superconducting films are discussed, and the progress achieved recently in the formation of such films is presented
{"title":"Progress in Use of Ultra-High Vacuum Cathodic Arcs for Deposition of Thin Film Superconducting Layers","authors":"J. Langner, M. Sadowski, P. Strzyzewski, R. Mirowski, J. Witkowski, S. Tazzari, L. Catani, A. Cianchi, J. Lorkiewicz, Roberto Russo, T. Paryjczak, J. Rogowski, J. Sekutowicz","doi":"10.1109/DEIV.2006.357356","DOIUrl":"https://doi.org/10.1109/DEIV.2006.357356","url":null,"abstract":"The paper reports on recent progress in the application of the UHV arc technology, which was proposed as an alternative solution for the deposition of thin superconducting films of pure niobium (Nb) upon the inner surfaces of RF cavities designed for particle accelerators. There are presented new experimental studies aimed at the deposition of superconducting films of pure niobium (Nb) and lead (Pb) needed for the modern accelerator technology. The main experimental results and characteristics of arc-deposited thin superconducting films are discussed, and the progress achieved recently in the formation of such films is presented","PeriodicalId":369861,"journal":{"name":"2006 International Symposium on Discharges and Electrical Insulation in Vacuum","volume":"174 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134118238","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}
In this paper, a two-dimensional statistical model for a single cathode spot of vacuum arc with copper cathode has been established to simulate its random walk and retrograde motion under external transverse magnetic field. In this preliminary work, a parameter, A, which was not yet related with the strength of applied transverse magnetic field in present work, was used to denote the different probabilities of cathode spot motion in Amperes direction and retrograde direction. With this model, the distribution of the probability density of cathode spot occurring in different area on cathode surface was simulated at different arcing time
{"title":"Statistical Simulation on the Random and Retrograde Motion of Single Cathode Spot of Vacuum Arc","authors":"Z. Shi, Jia Xiao, S. Jia, Yue Zhang, Lijun Wang","doi":"10.3131/jvsj.50.337","DOIUrl":"https://doi.org/10.3131/jvsj.50.337","url":null,"abstract":"In this paper, a two-dimensional statistical model for a single cathode spot of vacuum arc with copper cathode has been established to simulate its random walk and retrograde motion under external transverse magnetic field. In this preliminary work, a parameter, A, which was not yet related with the strength of applied transverse magnetic field in present work, was used to denote the different probabilities of cathode spot motion in Amperes direction and retrograde direction. With this model, the distribution of the probability density of cathode spot occurring in different area on cathode surface was simulated at different arcing time","PeriodicalId":369861,"journal":{"name":"2006 International Symposium on Discharges and Electrical Insulation in Vacuum","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125050191","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 : 2006-09-01DOI: 10.1109/DEIV.2006.357288
Zhiyuan Liu, Yaping Hu, Jimei Wang, Quan Wang, Dongli Bi, Guangli He
This paper introduces a new kind of slot type axial magnetic field (AMF) contact with iron plates. The objective of this paper is to analyze AMF characteristics of the new contact. The analysis was done by finite element method. Influence of iron plate parameters on AMF characteristics, such as axial magnetic flux density at current peak and current zero and phase shift time distribution, are shown. AMF characteristics of same contact without iron were analyzed for a comparison. It is found that a case gave the highest AMF 1.067T at current peak and its maximum AMF at current zero is 0.229T that is very close to the situation without iron 0.228T, while its phase shift time is as low as 0.6ms ~ l,6ms on the intermediate plane in contact gap. In this case parameters of iron plates are quantities of iron plates 12, inner diameter 16mm, outer diameter 46mm, height of iron plates 8mm and thickness of contact plates 3mm
{"title":"Analysis of Axial Magnetic Field of Slot Type Axial Magnetic Field Contacts with Iron Plates","authors":"Zhiyuan Liu, Yaping Hu, Jimei Wang, Quan Wang, Dongli Bi, Guangli He","doi":"10.1109/DEIV.2006.357288","DOIUrl":"https://doi.org/10.1109/DEIV.2006.357288","url":null,"abstract":"This paper introduces a new kind of slot type axial magnetic field (AMF) contact with iron plates. The objective of this paper is to analyze AMF characteristics of the new contact. The analysis was done by finite element method. Influence of iron plate parameters on AMF characteristics, such as axial magnetic flux density at current peak and current zero and phase shift time distribution, are shown. AMF characteristics of same contact without iron were analyzed for a comparison. It is found that a case gave the highest AMF 1.067T at current peak and its maximum AMF at current zero is 0.229T that is very close to the situation without iron 0.228T, while its phase shift time is as low as 0.6ms ~ l,6ms on the intermediate plane in contact gap. In this case parameters of iron plates are quantities of iron plates 12, inner diameter 16mm, outer diameter 46mm, height of iron plates 8mm and thickness of contact plates 3mm","PeriodicalId":369861,"journal":{"name":"2006 International Symposium on Discharges and Electrical Insulation in Vacuum","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132132408","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 : 2006-09-01DOI: 10.1109/DEIV.2006.357333
F. Ding, X. Duan, J. Zou, M. Liao
Controlled switching has been used extensively throughout the whole world for shunt capacitor banks. By precisely controlling where on the voltage waveform the contacts touch, it is possible to greatly reduce the magnitudes of the switching electrical transients. This paper presents the basic principle and the software algorithms of controlled switching for three-phase shunt capacitor banks with ungrounded neutral. The stringent performance requirement of the controlled vacuum circuit breaker with independent-pole-operated permanent magnetic actuator (PMA) and the synchronous controller based on the digital signal processor TMS320LF2407A that switching target tolerances should be within plusmn1ms was achieved. Numerous successful switching experiments on the 12kV voltage system demonstrated the well performance of the controlled switching system
{"title":"Controlled Switching of Shunt Capacitor Banks with Vacuum Circuit Breaker","authors":"F. Ding, X. Duan, J. Zou, M. Liao","doi":"10.1109/DEIV.2006.357333","DOIUrl":"https://doi.org/10.1109/DEIV.2006.357333","url":null,"abstract":"Controlled switching has been used extensively throughout the whole world for shunt capacitor banks. By precisely controlling where on the voltage waveform the contacts touch, it is possible to greatly reduce the magnitudes of the switching electrical transients. This paper presents the basic principle and the software algorithms of controlled switching for three-phase shunt capacitor banks with ungrounded neutral. The stringent performance requirement of the controlled vacuum circuit breaker with independent-pole-operated permanent magnetic actuator (PMA) and the synchronous controller based on the digital signal processor TMS320LF2407A that switching target tolerances should be within plusmn1ms was achieved. Numerous successful switching experiments on the 12kV voltage system demonstrated the well performance of the controlled switching system","PeriodicalId":369861,"journal":{"name":"2006 International Symposium on Discharges and Electrical Insulation in Vacuum","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134418407","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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