Twenty-First International Power Modulator Symposium, Conference最新文献

{"title":"Mass Erosion And Surface Voltage Holdoff Recovery Of High Current, High Vacuum Surface Discharge Switch Insulators","authors":"T. Engel, S. L. Wester, M. Kristiansen, L. Hatfield","doi":"10.1109/MODSYM.1994.597100","DOIUrl":"https://doi.org/10.1109/MODSYM.1994.597100","url":null,"abstract":"A high current discharge across the surface of an insulator in high vacuum is investigated. The mass erosion of the insulator and its surface voltage holdoff recovery are the two most important parameters of this investigation. Typically, the discharge current reaches 350 kA peak with a pulse length of 60 p (i.e., 5 periods of a damped sinusoidal pulse). The vacuum level is maintained at lo6 Torr. The insulator materials tested include a variety of polymeric (i.e., polyethylene, nylon, epoxy-fiberglass composites, and polyurethane) and ceramic (alumina, silicon nitride, and zirconia) insulators. Insulator mass erosion and surface voltage holdoff recovery versus electrode material has also been investigated. The electrode materials used include stainless steel, molybdenum, copper, copper-tungsten, brass, aluminum, and lead. Insulator materials that have low mass erosion and good surface voltage holdoff recovery have potential applications in high power vacuum switches. Breakdown voltage histories and mass erosion data were obtained for the plastics, but only breakdown voltages were obtained for the ceramics.","PeriodicalId":330796,"journal":{"name":"Twenty-First International Power Modulator Symposium, Conference","volume":"80 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128128541","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}

{"title":"Compact 500kV Generator","authors":"T. Engel, M. Kristiansen, J. Bridges","doi":"10.1109/MODSYM.1994.597079","DOIUrl":"https://doi.org/10.1109/MODSYM.1994.597079","url":null,"abstract":"","PeriodicalId":330796,"journal":{"name":"Twenty-First International Power Modulator Symposium, Conference","volume":"48 4-5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134363347","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}

{"title":"High Field Limitations Of Photoconductive Silicon","authors":"G. Gradinaru, G. Korony, T. Sudarshan","doi":"10.1109/MODSYM.1994.597054","DOIUrl":"https://doi.org/10.1109/MODSYM.1994.597054","url":null,"abstract":"","PeriodicalId":330796,"journal":{"name":"Twenty-First International Power Modulator Symposium, Conference","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131089177","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}

{"title":"High Power Repetitive Waveforms Generated By Compact Stacked Blumlein Pulsers","authors":"F. Davanloo, D. Borovina, J. Bhawalkar, C. B. Collins, F. Agee, L. Kingsley","doi":"10.1109/MODSYM.1994.597078","DOIUrl":"https://doi.org/10.1109/MODSYM.1994.597078","url":null,"abstract":"The repetitive stacked Blumlein pulse power sources developed at the University of Texas at Dallas (UTD) consist of several triaxial Blumleins stacked in series at one end. The lines are charged in parallel and synchronously commuted with a single thyratron at the other end. This allows switching t o take place at a low charging voltage relative t o the pulser output voltage. In this report, opportunities for packaging these pulsers into light and compact devices are investigated by studying Blumlein spacings on small scale prototypes. Considerable reductions in size and weight are demonstrated without significant degradations in the pulser performances. The promising capabilities of photoconductive switches fo r the use in these Blumlein pulsers are discussed.","PeriodicalId":330796,"journal":{"name":"Twenty-First International Power Modulator Symposium, Conference","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133686885","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}

{"title":"High Average Power Hydrogen Spark-gap Experiments","authors":"M. Ingram, S. Moran, M. Grothaus","doi":"10.1109/MODSYM.1994.597104","DOIUrl":"https://doi.org/10.1109/MODSYM.1994.597104","url":null,"abstract":"High-pressure gas switches enjoy widespread use in the scientific and commercial communities because of their ability to operate over a wide range of voltages and currents. However, a simultaneous requirement of continuous operation at high average power and high repetition rate has quite often limited their use. Improvement in the rep-rate capability of high pressure gas switches has been extensively investigated at the Dahlgren Laboratory of the Naval Surface Warfare Center (NSWC). Past work has demonstrated burstmode pulse repetition frequencies to 10 kHz, at voltages up to 500 kV or currents to 170 kA, by operating various highpressure hydrogen switches at approximately 50% of their self-break voltages. This paper describes recent work demonstrating continuous operation of one of these switches. Repetition rates up to 1.7 kHz at an average power of 16.5 kW and an operating voltage of 40 kV for >70 seconds are presented. The results for repetition rates from 670 Hz to 1.7 kHz show that the recovery curve obtained for burst-mode operation is reasonably predictive for continuous operation. Variation in the breakdown voltage during continuous operation is shown to be < 3 percent. The operating voltage, frequency and average power were limited by the experimental apparatus.","PeriodicalId":330796,"journal":{"name":"Twenty-First International Power Modulator Symposium, Conference","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125083555","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}

{"title":"High Current, High DI/DT Switching With Optimised GTO Thyristors","authors":"J. Bonthond, L. Ducimetière, G. Schroder, E. Vossenberg, M. Evans, F. Wakeman, R. Youdan","doi":"10.1109/MODSYM.1994.597049","DOIUrl":"https://doi.org/10.1109/MODSYM.1994.597049","url":null,"abstract":"The interdigitated gate structure of optimised high power GTO thyristors (Fast High Current Thyristors, FHCT’s) allows switching tens of kiloamps with a very high rate of current rise from blocking voltages of several kilovolts. Such high di/dt capabilities have up to now been restricted to gas switches. FHCT’s are making headway in fields of application which had traditionally been reserved for gas tubes. Solid state devices as these are for certain applications preferable to gas switches because they operate with higher efficiencies and have longer lifetimes. Besides that they do not need high voltage holding conditioning, cannot conduct erratically and are not subjected to electrode erosion. Normal GTO thyristors are optimised for their gate tum-off characteristics. This is achieved by three methods, heavy metal doping, diffused anode-shorts and irradiation. All these processes, in particular irradiation tend to slow down the turn-on characteristics of the device. However recent tests on a symmetrical 4.5kV, 66 mm unshorted anode FHCT, manufactured with light gold doping, show that the device can be used as a closing switch with excellent turn-on characteristics. Our tests have originally resulted in a dildt of 16 Wps for a half-sine wave current pulse of 32 kA amplitude. Recent tests achieved a di/dt of 2 0 W p s with a current pulse amplitude of 70 kA at an off-state blocking voltage of 1.6 kV. The tum-off capabilities of these devices are practically reduced to zero. One important operation condition is a fast and powerful gate drive. The gate controlled tum-on delay time is about 60011s. The measurements show that tum-on losses and conduction losses are only a few Joules. At this moment the construction of a switch consisting of ten in series connected 4.5 kV FHCT devices is being prepared. The effect of possible turn-on delay differences as well as the over-voltage protection circuit are discussed. If successful, the switch is an interesting alternative to the gas switches for the beam dumping kicker systems [ I ] of the Large Hadron Collider, where a 35 kV, 30 kA, 3 ps risetime switch is required.","PeriodicalId":330796,"journal":{"name":"Twenty-First International Power Modulator Symposium, Conference","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115451250","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}

{"title":"A FET Based Frequency And Duty Factor Agile 6 kV Pulse Generator","authors":"M. Barnes, G. Wait, C. Figley","doi":"10.1109/MODSYM.1994.597052","DOIUrl":"https://doi.org/10.1109/MODSYM.1994.597052","url":null,"abstract":"A pulse generator has been developed which has many potential applications. The pulse generator consists of a high-voltage modulator incorporating two stacked Field-Effect Transistor switches operating in a “push-pull” mode. A continuous 1 kV to 6 kV pulse train has been obtained with a prototype pulse generator over a frequency range from 1 Hz to 20 kHz. Pulse widths in the range from 250 ns to 1 s have been achieved with rise and fall times of 30 ns into a capacitive load of 26 pF. A 3 kHz, 5 kV version of this pulse generat,or has been installed and t,ested in the 300 keV injection line for t,he 500 MeV TRIUMF cyclotron. The circuit performance was evaluated with the aid of PSpice in t,he design stage and confirmed by measurement,s in the prototype. Results of measurements and simulations are presented.","PeriodicalId":330796,"journal":{"name":"Twenty-First International Power Modulator Symposium, Conference","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122714211","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}

{"title":"Power Semiconductor Switching Of Low Impedance High Energy Networks","authors":"R. Pastore, H. Singh, T. Podlesak, G. Ayres","doi":"10.1109/MODSYM.1994.597055","DOIUrl":"https://doi.org/10.1109/MODSYM.1994.597055","url":null,"abstract":"The military has been a growing interest in using electric guns over conventional powder based systems. Three types of guns are currently being explored: electromagnetic launchers or railguns, electrothermal chemical guns which use electrical energy to burn the propellant and coil guns which use solenoidal magnetic fields to launch the projectiles. All of these designs are in their infancy and as such the components that make up the system have not been developed enough to make these ideas competitive with conventional cannons. Current designs call for using vacuum switches or spark gaps as the main switching elements. While these switches can operate at the required voltages and currents they have ancillary equipment that is or can be large in size and weight. Spark gaps generally need to be pressurized to operate at high voltages and this requires an air compressor or gas bottles. The trigger generators tend to be large for spark gaps and vacuum switches. Vacuum switches have to operate under certain circuit conditions or they won't recover properly under reapplication of voltage. They have a high prefire rate, and require large trigger currents to keep the trigger pin operational. Certain designs of the modulator call for the switches to fire in a sequence to shape the current pulse delivered to the load. Without steering diodes in each line, switches that are on when the other switches begin to f i e will pass current in the reverse direction; recharging lines that should be discharged and lowering the overall efficiency of the system. Both spark gaps and vacuum switches can conduct current in both directions. At the U S . Army Pulse Power we have been investigating using high voltage thyristors as the main gun switch. Their ancillary requirements such as trigger generators are much smaller, typically rated at a few hundred volts and up to 100 A. No gas is needed, they are more reliable, and have a longer lifetime. Their disadvantage is their low breakdown voltage compared to gas switches, but they are easily operated in series and, if packaged correctly, there can be multiple devices in a single package, such as done by ABBI. Large area devices with amplifying gate structures can operate at currents of 136 kA reliably in millisecond pulses and have been operated over 150 kA. The need for steering diodes is negated if the reverse blocking capability of symmetric thyristors is utilized.","PeriodicalId":330796,"journal":{"name":"Twenty-First International Power Modulator Symposium, Conference","volume":"758 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116120873","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}

{"title":"Generation of High Power Pulses Using a SMES","authors":"H. Salbert, K. Jungst","doi":"10.1109/MODSYM.1994.597040","DOIUrl":"https://doi.org/10.1109/MODSYM.1994.597040","url":null,"abstract":"A model of a power modulator for linear accelerators that uses a SMES ( Superconducting Magnetic Energy Storage ) is being developed. It will generate 2 ms long, 3 kV / 300 A power pulses with a repetition rate of 10 Hz. For this device a fast IGBT-power-switch and a SMES are under development. The IGBT-power-switch consists of IGBT in parallel and in serial connection. The SMES is designed for ramping operations of more than 30 T/s.","PeriodicalId":330796,"journal":{"name":"Twenty-First International Power Modulator Symposium, Conference","volume":"351 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122645629","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}

{"title":"Influence Of Electrode Geometry On The High-field Characteristics Of Photoconductive Silicon Wafers","authors":"V. Madangarli, G. Gradinaru, G. Korony, T. Sudarshan, G. Loubriel, F. Zutavern, P. E. Patterson","doi":"10.1109/MODSYM.1994.597060","DOIUrl":"https://doi.org/10.1109/MODSYM.1994.597060","url":null,"abstract":"A series of experiment were conducted to study the influence of electrode geometry on the prebreakdown (and breakdown) characteristics of high resistivity ({rho} > 30 k{Omega}-cm), p-type Si wafers under quasi-uniform and non-uniform electric field configurations. In the quasi-uniform field configuration, the 1mm thick Si wafer was mounted between the slots of two plane parallel stainless steel disc electrodes (parallel), while the non-uniform field was obtained by mounting the wafer between two pillar-type electrodes with a hemispherical tip (pillar). The main objective of the above investigation was to verify if the uniform field configuration under a parallel system has a positive influence by reducing the field enhancement at the contact region, as opposed to the definite field enhancement present in the case of the non-uniform pillar system. Also, it was proposed to study the effect of the contact profile on the field distribution over the wafer surface and hence its influence on the high-field performance of the Si wafers.","PeriodicalId":330796,"journal":{"name":"Twenty-First International Power Modulator Symposium, Conference","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122037128","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}