Pub Date : 2000-09-18DOI: 10.1109/DEIV.2000.877250
S. Kobayashi, K. Sekikawa, K. Asano, Y. Saito
Ozonized water treatment has the advantages that organic contaminants can be removed to produce a passivated oxidized film on the surface and the treated surface condition can be kept in air. This technique has been applied to the surface treatment of oxygen-free copper electrodes. Experimental results revealed that the breakdown field at the 1st application of voltage was not always improved, but a significant conditioning effect was obtained without any in-situ precautions. Moreover, additional in-situ sputter cleaning on the ozonized water treated surface improved the 1st breakdown field. Surface analysis clarified that after the ozonized water treatment, the electrode surface was covered with an oxidized film (CuO) and this film was removed to expose bulk copper after conditioning by 500 repetitive breakdowns caused by applying impulse voltages. These results can be attributed to the characteristic that the treated surface can be kept in air.
{"title":"Surface conditions and electrical breakdown characteristics of ozonized water treated copper electrodes of a vacuum gap","authors":"S. Kobayashi, K. Sekikawa, K. Asano, Y. Saito","doi":"10.1109/DEIV.2000.877250","DOIUrl":"https://doi.org/10.1109/DEIV.2000.877250","url":null,"abstract":"Ozonized water treatment has the advantages that organic contaminants can be removed to produce a passivated oxidized film on the surface and the treated surface condition can be kept in air. This technique has been applied to the surface treatment of oxygen-free copper electrodes. Experimental results revealed that the breakdown field at the 1st application of voltage was not always improved, but a significant conditioning effect was obtained without any in-situ precautions. Moreover, additional in-situ sputter cleaning on the ozonized water treated surface improved the 1st breakdown field. Surface analysis clarified that after the ozonized water treatment, the electrode surface was covered with an oxidized film (CuO) and this film was removed to expose bulk copper after conditioning by 500 repetitive breakdowns caused by applying impulse voltages. These results can be attributed to the characteristic that the treated surface can be kept in air.","PeriodicalId":429452,"journal":{"name":"Proceedings ISDEIV. 19th International Symposium on Discharges and Electrical Insulation in Vacuum (Cat. No.00CH37041)","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115232795","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 : 2000-09-18DOI: 10.1109/DEIV.2000.879089
K. Takeda, M. Sugimoto
Cathode spots of a vacuum arc have the smart property to selectively remove oxide on a metal surface. Analyses of a surface treated by a vacuum arc revealed that various interesting surface modifications occurred during the removal of the oxide. The authors have investigated these effects to open up new applications of the vacuum arc. The cathode spots can remove inclusions which often cause surface defects. They attack not only oxide but also carbide inclusions and eliminate them from the surface by evaporation. Dry cleaning to remove the organic compound can also be possible. Degreasing (removal of grease) proceeds in parallel to the removal of oxide. The vacuum arc treatment results in the increase of hardness in the surface layer due to the rapid heating and quenching.
{"title":"Surface modification by cathode spots of a vacuum arc","authors":"K. Takeda, M. Sugimoto","doi":"10.1109/DEIV.2000.879089","DOIUrl":"https://doi.org/10.1109/DEIV.2000.879089","url":null,"abstract":"Cathode spots of a vacuum arc have the smart property to selectively remove oxide on a metal surface. Analyses of a surface treated by a vacuum arc revealed that various interesting surface modifications occurred during the removal of the oxide. The authors have investigated these effects to open up new applications of the vacuum arc. The cathode spots can remove inclusions which often cause surface defects. They attack not only oxide but also carbide inclusions and eliminate them from the surface by evaporation. Dry cleaning to remove the organic compound can also be possible. Degreasing (removal of grease) proceeds in parallel to the removal of oxide. The vacuum arc treatment results in the increase of hardness in the surface layer due to the rapid heating and quenching.","PeriodicalId":429452,"journal":{"name":"Proceedings ISDEIV. 19th International Symposium on Discharges and Electrical Insulation in Vacuum (Cat. No.00CH37041)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117146874","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 : 2000-09-18DOI: 10.1109/DEIV.2000.877254
S. Barengolts, Yu.A. Barengolts
Emission processes are treated for the case where dielectric and semiconductor microinclusions are present on the surface of a metal cathode. It has been shown that the emission current-voltage characteristic plotted in the Fowler-Nordheim coordinates is close to a straight line corresponding to a high field enhancement factor. A stationary problem on the heating of a nonmetal microprotrusion by the field emission current has been solved. Calculations have shown that for explosive emission processes to be initiated in this case, lower critical currents and lower Joule energy spatial densities are required then in the case of metal microprotrusions on a cathode. This is the reason why the initiation of a vacuum discharge and its operation at the early stage occur at those sites where nonmetal inclusions are present. For a vacuum arc discharge, the required electric field strength is achieved through the charging of the surface of a nonmetal inclusion by the ion current from the arc plasma.
{"title":"On the role of nonmetal inclusions at the cathode surface in the initiation and self-sustaining of a vacuum discharge","authors":"S. Barengolts, Yu.A. Barengolts","doi":"10.1109/DEIV.2000.877254","DOIUrl":"https://doi.org/10.1109/DEIV.2000.877254","url":null,"abstract":"Emission processes are treated for the case where dielectric and semiconductor microinclusions are present on the surface of a metal cathode. It has been shown that the emission current-voltage characteristic plotted in the Fowler-Nordheim coordinates is close to a straight line corresponding to a high field enhancement factor. A stationary problem on the heating of a nonmetal microprotrusion by the field emission current has been solved. Calculations have shown that for explosive emission processes to be initiated in this case, lower critical currents and lower Joule energy spatial densities are required then in the case of metal microprotrusions on a cathode. This is the reason why the initiation of a vacuum discharge and its operation at the early stage occur at those sites where nonmetal inclusions are present. For a vacuum arc discharge, the required electric field strength is achieved through the charging of the surface of a nonmetal inclusion by the ion current from the arc plasma.","PeriodicalId":429452,"journal":{"name":"Proceedings ISDEIV. 19th International Symposium on Discharges and Electrical Insulation in Vacuum (Cat. No.00CH37041)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125870719","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 : 2000-09-18DOI: 10.1109/DEIV.2000.879087
V. P. Grigoryev, T. Koval
The triode with virtual cathode (VC) generates gigawatt pulses in wide frequency band. Basically, existing theoretical investigations of this system were carried out by method of numerical simulations and did not explain many experimental facts. The analytical description is more successful for investigation of generation mechanism. Two theoretical models describing the generation mechanism of the electromagnetic oscillation radiation in the virtual cathode triode are presented in this paper.
{"title":"Generation mechanism in triode with virtual cathode","authors":"V. P. Grigoryev, T. Koval","doi":"10.1109/DEIV.2000.879087","DOIUrl":"https://doi.org/10.1109/DEIV.2000.879087","url":null,"abstract":"The triode with virtual cathode (VC) generates gigawatt pulses in wide frequency band. Basically, existing theoretical investigations of this system were carried out by method of numerical simulations and did not explain many experimental facts. The analytical description is more successful for investigation of generation mechanism. Two theoretical models describing the generation mechanism of the electromagnetic oscillation radiation in the virtual cathode triode are presented in this paper.","PeriodicalId":429452,"journal":{"name":"Proceedings ISDEIV. 19th International Symposium on Discharges and Electrical Insulation in Vacuum (Cat. No.00CH37041)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123536840","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 : 2000-09-18DOI: 10.1109/DEIV.2000.879049
M. Nikitin, V. Egorov
The method of metal evaporation in a vacuum by a nonself-maintained discharge is applied as for deposition of thin films and coatings, and as for diffusion saturation of metallic materials. Change of the thermoionic cathode temperature and discharge power provides the evaporator work in wide interval of currents (1-100 A) and voltages (30-700 V), initiating the fluxes of deposited atoms with ionization degree from 2 to about 100%. The dependence of initiation conditions and discharge burning were considered due to vacuum, the evaporated metals, the cathode/anode distance and the cathode temperature in voltage range from 50 to 500 V with currents to 5 A. The conditions of discharge initiation are improved with decreasing basic pressure in chamber lower than 0.01 Pa. The increasing of pressure lead to burning of the shunting glow discharge through residual gases. The optimal cathode temperatures are in range from 1800 to 2200/spl deg/C. The plasma parameters were determined from I-V characteristics of a Langmuir probe. The temperature and density of the plasma electrons are changed in intervals, respectively, (8-12) /spl times/10/sup 4/ K and (0.4-5)/spl times/10/sup 1 /cm/sup -3/. The density of ion current was 5 mA cm/sup -2/. Maximum values of ionization degree for evaporated Cu, Cr and Al atoms are attained at 100,200 and 250 V, respectively, and are of the range 30-50%.
{"title":"Some characteristics of non-self-maintained discharge in metal vapor","authors":"M. Nikitin, V. Egorov","doi":"10.1109/DEIV.2000.879049","DOIUrl":"https://doi.org/10.1109/DEIV.2000.879049","url":null,"abstract":"The method of metal evaporation in a vacuum by a nonself-maintained discharge is applied as for deposition of thin films and coatings, and as for diffusion saturation of metallic materials. Change of the thermoionic cathode temperature and discharge power provides the evaporator work in wide interval of currents (1-100 A) and voltages (30-700 V), initiating the fluxes of deposited atoms with ionization degree from 2 to about 100%. The dependence of initiation conditions and discharge burning were considered due to vacuum, the evaporated metals, the cathode/anode distance and the cathode temperature in voltage range from 50 to 500 V with currents to 5 A. The conditions of discharge initiation are improved with decreasing basic pressure in chamber lower than 0.01 Pa. The increasing of pressure lead to burning of the shunting glow discharge through residual gases. The optimal cathode temperatures are in range from 1800 to 2200/spl deg/C. The plasma parameters were determined from I-V characteristics of a Langmuir probe. The temperature and density of the plasma electrons are changed in intervals, respectively, (8-12) /spl times/10/sup 4/ K and (0.4-5)/spl times/10/sup 1 /cm/sup -3/. The density of ion current was 5 mA cm/sup -2/. Maximum values of ionization degree for evaporated Cu, Cr and Al atoms are attained at 100,200 and 250 V, respectively, and are of the range 30-50%.","PeriodicalId":429452,"journal":{"name":"Proceedings ISDEIV. 19th International Symposium on Discharges and Electrical Insulation in Vacuum (Cat. No.00CH37041)","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116072998","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 : 2000-09-18DOI: 10.1109/DEIV.2000.877313
D. Alferov, V. Sidorov
Results of researches of pulse high-current vacuum arc evolution in a six-gap rod electrode system in the peak current range 10-100 kA are represented. The researches were carried out on a demountable vacuum tube with simultaneous registration of electrical parameters of discharge, discharge plasma glow and luminous spots on electrodes. Fast discharge transition from a trigger unit into inter-rod gaps at reaching current to 5-9 kA was revealed. Correlation between a moment of step-like voltage fall and a moment of formation of new discharge channel in the inter-rod gaps was shown. Various modes of vacuum arc in an inter-rod gaps and multiplication of discharge channels on all inter-rod gaps with growth of a current were observed. An effect of rise of current rate on process of a vacuum arc evolution was investigated.
{"title":"High-current vacuum arc evolution in a six-gap rod electrode system","authors":"D. Alferov, V. Sidorov","doi":"10.1109/DEIV.2000.877313","DOIUrl":"https://doi.org/10.1109/DEIV.2000.877313","url":null,"abstract":"Results of researches of pulse high-current vacuum arc evolution in a six-gap rod electrode system in the peak current range 10-100 kA are represented. The researches were carried out on a demountable vacuum tube with simultaneous registration of electrical parameters of discharge, discharge plasma glow and luminous spots on electrodes. Fast discharge transition from a trigger unit into inter-rod gaps at reaching current to 5-9 kA was revealed. Correlation between a moment of step-like voltage fall and a moment of formation of new discharge channel in the inter-rod gaps was shown. Various modes of vacuum arc in an inter-rod gaps and multiplication of discharge channels on all inter-rod gaps with growth of a current were observed. An effect of rise of current rate on process of a vacuum arc evolution was investigated.","PeriodicalId":429452,"journal":{"name":"Proceedings ISDEIV. 19th International Symposium on Discharges and Electrical Insulation in Vacuum (Cat. No.00CH37041)","volume":"209 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122433238","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 : 2000-09-18DOI: 10.1109/DEIV.2000.879057
I. Levchenko
Numerical simulation of a new method proposed previously for plasma deposition allowing creation of the unique surface structures was carried out. The primary mechanisms were studied and the surface structures were calculated. The present paper describes: model of numerical simulation and conditions of digitization, the set of surface structures calculated, boundary conditions, numerical studying of an electrical field distribution in the oscillation area, numerically calculated ion traces and distribution of ion precipitation to the substrate under plasma oscillation area. The investigation proposed contains the recommendations with respect to experimental investigations being planned, and possible advantages of a new technique for complex surface structure formation with no mask used.
{"title":"Surface structure formation by means of plasma oscillations. Numerical simulation and the principal regularities","authors":"I. Levchenko","doi":"10.1109/DEIV.2000.879057","DOIUrl":"https://doi.org/10.1109/DEIV.2000.879057","url":null,"abstract":"Numerical simulation of a new method proposed previously for plasma deposition allowing creation of the unique surface structures was carried out. The primary mechanisms were studied and the surface structures were calculated. The present paper describes: model of numerical simulation and conditions of digitization, the set of surface structures calculated, boundary conditions, numerical studying of an electrical field distribution in the oscillation area, numerically calculated ion traces and distribution of ion precipitation to the substrate under plasma oscillation area. The investigation proposed contains the recommendations with respect to experimental investigations being planned, and possible advantages of a new technique for complex surface structure formation with no mask used.","PeriodicalId":429452,"journal":{"name":"Proceedings ISDEIV. 19th International Symposium on Discharges and Electrical Insulation in Vacuum (Cat. No.00CH37041)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122143221","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 : 2000-09-18DOI: 10.1109/DEIV.2000.879098
A. Emelyanov, L.A. Prokhodova
The experimental data on the conditioning of the film electrodes of the accelerating gap of a microchannel image amplifier with a series of high-voltage nanosecond pulses are presented. The possibility of the exclusion of a visual control for changes in the local glows of the screen during conditioning and this process unification is shown.
{"title":"On regime for increasing the breakdown strength of vacuum gap between the microchannel plate and screen of the image amplifier","authors":"A. Emelyanov, L.A. Prokhodova","doi":"10.1109/DEIV.2000.879098","DOIUrl":"https://doi.org/10.1109/DEIV.2000.879098","url":null,"abstract":"The experimental data on the conditioning of the film electrodes of the accelerating gap of a microchannel image amplifier with a series of high-voltage nanosecond pulses are presented. The possibility of the exclusion of a visual control for changes in the local glows of the screen during conditioning and this process unification is shown.","PeriodicalId":429452,"journal":{"name":"Proceedings ISDEIV. 19th International Symposium on Discharges and Electrical Insulation in Vacuum (Cat. No.00CH37041)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122203256","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 : 2000-09-18DOI: 10.1109/DEIV.2000.879051
V. Khoroshikh, S. A. Leonov, V. A. Belous
An installation for vacuum-arc droplet-free film deposition was designed. It contains two rectilinear plasma sources, in whose cylindrical anodes the disk filtering shields are placed. The investigated variant of installation provides ion current at a level 2.4 A at a current of the arc in each of plasma sources 100 A. The deposition rate of 5 /spl mu/m/h for titanium nitride films was achieved over the rotating cylindrical detail of height 50 mm and diameter of 45 mm. It is shown also that the installation allows to receive coatings by thickness up to 3 microns at the average size of microroughnesses on its surface about 0.08-0.09 microns.
{"title":"Installation for vacuum-arc film deposition by filtered plasma fluxes","authors":"V. Khoroshikh, S. A. Leonov, V. A. Belous","doi":"10.1109/DEIV.2000.879051","DOIUrl":"https://doi.org/10.1109/DEIV.2000.879051","url":null,"abstract":"An installation for vacuum-arc droplet-free film deposition was designed. It contains two rectilinear plasma sources, in whose cylindrical anodes the disk filtering shields are placed. The investigated variant of installation provides ion current at a level 2.4 A at a current of the arc in each of plasma sources 100 A. The deposition rate of 5 /spl mu/m/h for titanium nitride films was achieved over the rotating cylindrical detail of height 50 mm and diameter of 45 mm. It is shown also that the installation allows to receive coatings by thickness up to 3 microns at the average size of microroughnesses on its surface about 0.08-0.09 microns.","PeriodicalId":429452,"journal":{"name":"Proceedings ISDEIV. 19th International Symposium on Discharges and Electrical Insulation in Vacuum (Cat. No.00CH37041)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129472362","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 : 2000-09-18DOI: 10.1109/DEIV.2000.877278
S. Shkol’nik
The paper reflects the condition of research into the vacuum arc with such an impregnation of a cathode with hydrogen that the average share of each atom of metal is roughly one H atom. The introductory sections discuss in brief the basic characteristics of the Me-H system and techniques of impregnation of different metals with H. The subsequent sections present the results of investigations of cathode spot parameters and arc characteristics at various Ti cathode impregnation degree. A comparison with characteristics of degassed cathodes demonstrated marked differences: at impregnation of a cathode with H, the velocity of cathode spot motion grows, the current per spot falls off, erosion diminishes; the high-current arc burns steadily and at a lower voltage; the current, critical for anode spot formation, grows significantly. The results given show that the use of H-impregnated cathodes can prove promising for various applications.
{"title":"Arc discharges with gas-impregnated cathodes in vacuum","authors":"S. Shkol’nik","doi":"10.1109/DEIV.2000.877278","DOIUrl":"https://doi.org/10.1109/DEIV.2000.877278","url":null,"abstract":"The paper reflects the condition of research into the vacuum arc with such an impregnation of a cathode with hydrogen that the average share of each atom of metal is roughly one H atom. The introductory sections discuss in brief the basic characteristics of the Me-H system and techniques of impregnation of different metals with H. The subsequent sections present the results of investigations of cathode spot parameters and arc characteristics at various Ti cathode impregnation degree. A comparison with characteristics of degassed cathodes demonstrated marked differences: at impregnation of a cathode with H, the velocity of cathode spot motion grows, the current per spot falls off, erosion diminishes; the high-current arc burns steadily and at a lower voltage; the current, critical for anode spot formation, grows significantly. The results given show that the use of H-impregnated cathodes can prove promising for various applications.","PeriodicalId":429452,"journal":{"name":"Proceedings ISDEIV. 19th International Symposium on Discharges and Electrical Insulation in Vacuum (Cat. No.00CH37041)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123867396","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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