K. Harris, F. Cathell, B. E. Strickland, J. Crawford, M. Jung, W. Mayerhofer, T. Schweizer, E. Zeyfang
Maxwell Laboratories, Inc. (MLI) has designed, delivered and tested power supplies rated at 240 kJ/s, 50 kV and 120 kJ/s, 30 kV to DLR for use in a high-power, pulsed CO/sub 2/ laser. The optical performance of this electron-beam sustained laser with an active volume of 20 liters and a transversal gas flow is strongly dependent on the shot-to-shot repeatability of the power supply(s). Testing of the power supplies was performed by operating the electron-beam and main discharge pulse forming networks (PFNs) into a resistive load at the maximum repetition-rate of the laser, 100 Hz, for the rated burst length of 1000 pulses. The PFN was switched using a rep-rate spark gap pressurized with compressed air to less than 3 atm of pressure. The regulation (shot-to-shot repeatability) of the 240 kJ/s supply operating at 40-45 kV was
{"title":"240 kJ/s and 120 kJ/s power supplies for high regulation, minimum unplanned downtime applications","authors":"K. Harris, F. Cathell, B. E. Strickland, J. Crawford, M. Jung, W. Mayerhofer, T. Schweizer, E. Zeyfang","doi":"10.1109/PPC.1995.599819","DOIUrl":"https://doi.org/10.1109/PPC.1995.599819","url":null,"abstract":"Maxwell Laboratories, Inc. (MLI) has designed, delivered and tested power supplies rated at 240 kJ/s, 50 kV and 120 kJ/s, 30 kV to DLR for use in a high-power, pulsed CO/sub 2/ laser. The optical performance of this electron-beam sustained laser with an active volume of 20 liters and a transversal gas flow is strongly dependent on the shot-to-shot repeatability of the power supply(s). Testing of the power supplies was performed by operating the electron-beam and main discharge pulse forming networks (PFNs) into a resistive load at the maximum repetition-rate of the laser, 100 Hz, for the rated burst length of 1000 pulses. The PFN was switched using a rep-rate spark gap pressurized with compressed air to less than 3 atm of pressure. The regulation (shot-to-shot repeatability) of the 240 kJ/s supply operating at 40-45 kV was </spl plusmn/0.05%. This regulation was achieved through the use of a modular power supply design using 12 kJ/s CCDS switching power supply modules. In addition to the patented high regulation topology of the individual CCDS units, the key to achieving the high regulation is reducing the size of the quantum of charge delivered at the end of the charging cycle. The techniques used to assure graceful degradation (unplanned downtime minimization), high regulation and user friendly assembly as well as the technique for parallel control of tens of modules are discussed in this paper. In addition, a comparison of the practical limitations, advantages and disadvantages of this technique verses conventional 60 Hz approaches are discussed.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"38 1","pages":"1437-1442 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80801749","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}
A pulse generator consisting of a coaxial cable and a high voltage modulator, incorporating two stacks of field-effect transistor (FET) switches operating in "push-pull" mode, has been designed and built. The modulator generates a continuous, unipolar, pulse train at a fundamental frequency of 1 MHz and a magnitude of 10 kV. The rise and fall times of the pulses are less than 39 ns. The two stacks each utilize 14 FETS, which are individually rated at 1 kV. The design incorporates a low-loss coaxial cable on which pulses are stored. Extensive PSpice simulations have been carried out to evaluate various design options. Subsequent measurements on the prototype pulse generator confirm the PSpice predictions.
{"title":"Design for a FET based 1 MHz, 10 kV pulse generator","authors":"M. Barnes, G. Wait","doi":"10.1109/PPC.1995.599802","DOIUrl":"https://doi.org/10.1109/PPC.1995.599802","url":null,"abstract":"A pulse generator consisting of a coaxial cable and a high voltage modulator, incorporating two stacks of field-effect transistor (FET) switches operating in \"push-pull\" mode, has been designed and built. The modulator generates a continuous, unipolar, pulse train at a fundamental frequency of 1 MHz and a magnitude of 10 kV. The rise and fall times of the pulses are less than 39 ns. The two stacks each utilize 14 FETS, which are individually rated at 1 kV. The design incorporates a low-loss coaxial cable on which pulses are stored. Extensive PSpice simulations have been carried out to evaluate various design options. Subsequent measurements on the prototype pulse generator confirm the PSpice predictions.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"28 1","pages":"1335-1340 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89333191","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}
F. Wysocki, J. Benage, J. Shlachter, J. Cochrane, J. Stokes, H. Oona, W. Anderson, W. Broste, B. Warthen, N. Roderick
The plasma gate switch is a novel technique for producing a long conduction time vacuum opening switch. The switch consists of an aluminum foil which connects the cathode to the anode in a coaxial geometry. The foil is designed so that the maximum axial acceleration is in the center of the foil and that at the appropriate time, the center opens up and magnetic flux is carried down the gun to the load region. The switch is designed to minimize the amount of mass transported into the load region. The authors have completed the first experimental test of this design and present results from that test. These results indicate there were some asymmetry problems in the construction of the switch but that otherwise the switch performed as expected.
{"title":"Plasma gate switch experiment on Pegasus II","authors":"F. Wysocki, J. Benage, J. Shlachter, J. Cochrane, J. Stokes, H. Oona, W. Anderson, W. Broste, B. Warthen, N. Roderick","doi":"10.1109/PPC.1995.599768","DOIUrl":"https://doi.org/10.1109/PPC.1995.599768","url":null,"abstract":"The plasma gate switch is a novel technique for producing a long conduction time vacuum opening switch. The switch consists of an aluminum foil which connects the cathode to the anode in a coaxial geometry. The foil is designed so that the maximum axial acceleration is in the center of the foil and that at the appropriate time, the center opens up and magnetic flux is carried down the gun to the load region. The switch is designed to minimize the amount of mass transported into the load region. The authors have completed the first experimental test of this design and present results from that test. These results indicate there were some asymmetry problems in the construction of the switch but that otherwise the switch performed as expected.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"os-45 1","pages":"1142-1147 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87238997","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}
A variety of soft X-ray diagnostics are being fielded on the Los Alamos National Laboratory Pegasus and Procyon pulsed power systems and also being fielded on joint US/Russian magnetized target fusion experiments known as MAGO (Magnitoye Obzhatiye). We have designed a low-cost modular photoemissive detector designated the XRD-96 that uses commercial 1100 series aluminum for the photocathode. In addition to photocathode detectors a number of designs using solid state silicon photodiodes have been designed and fielded. We also present a soft X-ray time-integrated pinhole camera system that uses standard type TMAX-400 photographic film that obviates the need for expensive and no longer produced zero-overcoat soft X-ray emulsion film. In a typical experiment the desired spectral energy cuts, signal intensity levels, and desired field of view will determine diagnostic geometry and X-ray filters selected. We have developed several computer codes to assist in the diagnostic design process and data deconvolution. Examples of the diagnostic design process and data analysis for a typical pulsed power experiment are presented.
{"title":"Soft X-ray diagnostics for pulsed power machines","authors":"G. Idzorek, W. Coulter, P. Walsh, R. Montoya","doi":"10.1109/PPC.1995.599740","DOIUrl":"https://doi.org/10.1109/PPC.1995.599740","url":null,"abstract":"A variety of soft X-ray diagnostics are being fielded on the Los Alamos National Laboratory Pegasus and Procyon pulsed power systems and also being fielded on joint US/Russian magnetized target fusion experiments known as MAGO (Magnitoye Obzhatiye). We have designed a low-cost modular photoemissive detector designated the XRD-96 that uses commercial 1100 series aluminum for the photocathode. In addition to photocathode detectors a number of designs using solid state silicon photodiodes have been designed and fielded. We also present a soft X-ray time-integrated pinhole camera system that uses standard type TMAX-400 photographic film that obviates the need for expensive and no longer produced zero-overcoat soft X-ray emulsion film. In a typical experiment the desired spectral energy cuts, signal intensity levels, and desired field of view will determine diagnostic geometry and X-ray filters selected. We have developed several computer codes to assist in the diagnostic design process and data deconvolution. Examples of the diagnostic design process and data analysis for a typical pulsed power experiment are presented.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"124 2 1","pages":"981-986 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90463848","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}
A. Kim, B. Kovalchuk, V. Kokshenev, N. Kurmaev, S. Loginov, F. I. Fursov, V. P. Jakovlev
The concept of the multi module pulsed power system using the inductive energy storage (IES) technology may be developed on a base of one of two possible plasma opening switch (POS) designs. First is the multi POS design with the number of the switches being equal to the number of the modules. The main advantages of this design are the possibility to perform the full scale investigation of the single module prototype including the POS before the total system will be built, and the possibility to increase the power of the system by adding some number of the well known elements. The main disadvantage of the multi POS design seems to be the jitter in the switch openings-the problem which is not solved at present. The second, single POS design, presumes one POS switching the energy from all the modules into the load. The main advantage of the design is the absence of the POS synchronization problem. In the same time the single POS design requires building of the total system before the POS could be tested resulting in a risk of worse opening or some other problems which may appear at increased POS current level. The GIT4-GIT8 facilities at HCEI represent a test bed allowing investigation of the single POS design at successively increasing POS current (2.5-5 MA). The goal of the experiments described was to clear the current distribution in the switch region on GIT8 and to determine possible restrictions which could limit the application of the given single POS design.
{"title":"Current distribution during conduction and POS opening on GIT8","authors":"A. Kim, B. Kovalchuk, V. Kokshenev, N. Kurmaev, S. Loginov, F. I. Fursov, V. P. Jakovlev","doi":"10.1109/PPC.1995.596484","DOIUrl":"https://doi.org/10.1109/PPC.1995.596484","url":null,"abstract":"The concept of the multi module pulsed power system using the inductive energy storage (IES) technology may be developed on a base of one of two possible plasma opening switch (POS) designs. First is the multi POS design with the number of the switches being equal to the number of the modules. The main advantages of this design are the possibility to perform the full scale investigation of the single module prototype including the POS before the total system will be built, and the possibility to increase the power of the system by adding some number of the well known elements. The main disadvantage of the multi POS design seems to be the jitter in the switch openings-the problem which is not solved at present. The second, single POS design, presumes one POS switching the energy from all the modules into the load. The main advantage of the design is the absence of the POS synchronization problem. In the same time the single POS design requires building of the total system before the POS could be tested resulting in a risk of worse opening or some other problems which may appear at increased POS current level. The GIT4-GIT8 facilities at HCEI represent a test bed allowing investigation of the single POS design at successively increasing POS current (2.5-5 MA). The goal of the experiments described was to clear the current distribution in the switch region on GIT8 and to determine possible restrictions which could limit the application of the given single POS design.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"24 1","pages":"226-231 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73461383","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}
P. Choi, C. Dumitrescu‐Zoita, B. Etlicher, A.V. Shislov
The recording of the spatial structure of a high temperature plasma in the hard X-ray region is limited by the problem of shine-through associated with a thin aperture material, when fine resolution is required, as well as the low-emission flux from the plasma in the high energy spectral region. In this paper, the design and performance of a hard X-ray camera is presented to monitor plasma radiation structure emitting in a spectral region above 12 keV, using the slit-wire camera design. In a series of experiments on GIT-4, the camera was used successfully to identify the spatial structure of the hard X-ray emission from the plasma and demonstrated the existence of a sub-100 /spl mu/m diameter, cm long plasma column emitting in the 18-30 keV region.
{"title":"A hard X-ray slit-wire camera","authors":"P. Choi, C. Dumitrescu‐Zoita, B. Etlicher, A.V. Shislov","doi":"10.1109/PPC.1995.599724","DOIUrl":"https://doi.org/10.1109/PPC.1995.599724","url":null,"abstract":"The recording of the spatial structure of a high temperature plasma in the hard X-ray region is limited by the problem of shine-through associated with a thin aperture material, when fine resolution is required, as well as the low-emission flux from the plasma in the high energy spectral region. In this paper, the design and performance of a hard X-ray camera is presented to monitor plasma radiation structure emitting in a spectral region above 12 keV, using the slit-wire camera design. In a series of experiments on GIT-4, the camera was used successfully to identify the spatial structure of the hard X-ray emission from the plasma and demonstrated the existence of a sub-100 /spl mu/m diameter, cm long plasma column emitting in the 18-30 keV region.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"282 1","pages":"886-891 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75344206","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}
The Center for Electromechanics at The University of Texas (CEM-UT) is in the final fabrication and testing phase of the cannon caliber electromagnetic launcher system (CCEML). The objective of the CCEML program is to develop an electromagnetic cannon caliber launcher (30 mm) and power supply capable of firing three, five round salvos at a rate of 5 Hz. The scope of this paper is design and testing of the CCEML gun discharge subsystem, which consists of an explosive opening switch (EOS) and a thyristor gun closing switch module (GSM). The first part of the paper covers component development. In the second part, performance data of both switches is presented including high current EOS performance and GSM turn-on, turn-off, and parallel thyristor sharing data.
{"title":"Design and testing of a coaxial opening switch and solid state closing switch for the cannon caliber electromagnetic launcher system (CCEML)","authors":"R. Lee, D. Wehrlen, C. Penney","doi":"10.1109/PPC.1995.599801","DOIUrl":"https://doi.org/10.1109/PPC.1995.599801","url":null,"abstract":"The Center for Electromechanics at The University of Texas (CEM-UT) is in the final fabrication and testing phase of the cannon caliber electromagnetic launcher system (CCEML). The objective of the CCEML program is to develop an electromagnetic cannon caliber launcher (30 mm) and power supply capable of firing three, five round salvos at a rate of 5 Hz. The scope of this paper is design and testing of the CCEML gun discharge subsystem, which consists of an explosive opening switch (EOS) and a thyristor gun closing switch module (GSM). The first part of the paper covers component development. In the second part, performance data of both switches is presented including high current EOS performance and GSM turn-on, turn-off, and parallel thyristor sharing data.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"40 1","pages":"1329-1334 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77958219","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}
The author briefly reviews the following high power microwave pulsed sources: slow wave structures including relativistic magnetrons, BWOs, Cerenkov masers, and magnetically insulated transmission line oscillators.
{"title":"Review of high power microwave pulsed sources","authors":"A. Biggs","doi":"10.1109/PPC.1995.596460","DOIUrl":"https://doi.org/10.1109/PPC.1995.596460","url":null,"abstract":"The author briefly reviews the following high power microwave pulsed sources: slow wave structures including relativistic magnetrons, BWOs, Cerenkov masers, and magnetically insulated transmission line oscillators.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"39 1","pages":"86-90 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75239137","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}
Consideration is given to the process of cathode-anode gap overlap by a comparatively dense electron flow in pulsed power supply switches. A nonlinear nonsteady-state hydrodynamic theory of the process has been constructed. Discovered and investigated is the nonlinear phenomenon of electron self-acceleration owing to the interactions of their Coulomb fields. This phenomenon allows the electron front to overlap the cathode-anode distance in times that are short as compared to the single electron time-of-flight in an applied electric field.
{"title":"The phenomenon of non-linear cathode-emitted particle self-acceleration ~in pulsed power supply switches","authors":"A. Pashchenko, V. Novikov, Y. Tkach","doi":"10.1109/PPC.1995.599718","DOIUrl":"https://doi.org/10.1109/PPC.1995.599718","url":null,"abstract":"Consideration is given to the process of cathode-anode gap overlap by a comparatively dense electron flow in pulsed power supply switches. A nonlinear nonsteady-state hydrodynamic theory of the process has been constructed. Discovered and investigated is the nonlinear phenomenon of electron self-acceleration owing to the interactions of their Coulomb fields. This phenomenon allows the electron front to overlap the cathode-anode distance in times that are short as compared to the single electron time-of-flight in an applied electric field.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"21 1","pages":"852-856 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73583502","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}
E. V. Grabovskiĭ, S. L. Nedoseev, V. E. Pichugin, V. Smirnov, V.V. Zajivikhin, B.M. Oleynik
A parallel current addition at power facilities is carried out according to two main schemes as follows: (1) adding in generator water part installations "SATURN" and "PBFA-II" (SNL, USA); and (2) convolution in vacuum part "Angara-5-1" (TRINITI, Russia). The second scheme may be important for increasing of facilities' size, because it allows a decrease in vacuum isolator dimensions. The proposed paper deals with some experimental results on the parallel current addition at a common load. A jitter of parallel current addition is a significant effect of "Angara-5-1" operation. Quantitatively it is a square mean of time delay of modules T1-T8, when voltage of every module achieves 0.1 of its maximum value. These moments may be determined with +/-2 ns' accuracy.
{"title":"Parallel MITLs current addition at common load","authors":"E. V. Grabovskiĭ, S. L. Nedoseev, V. E. Pichugin, V. Smirnov, V.V. Zajivikhin, B.M. Oleynik","doi":"10.1109/PPC.1995.599745","DOIUrl":"https://doi.org/10.1109/PPC.1995.599745","url":null,"abstract":"A parallel current addition at power facilities is carried out according to two main schemes as follows: (1) adding in generator water part installations \"SATURN\" and \"PBFA-II\" (SNL, USA); and (2) convolution in vacuum part \"Angara-5-1\" (TRINITI, Russia). The second scheme may be important for increasing of facilities' size, because it allows a decrease in vacuum isolator dimensions. The proposed paper deals with some experimental results on the parallel current addition at a common load. A jitter of parallel current addition is a significant effect of \"Angara-5-1\" operation. Quantitatively it is a square mean of time delay of modules T1-T8, when voltage of every module achieves 0.1 of its maximum value. These moments may be determined with +/-2 ns' accuracy.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"10 1","pages":"1011-1016 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73669318","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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