H. Schilling, J. Schluter, M. Peters, K. Nielsen, J. T. Naff, H. Hammon
{"title":"High voltage generator with fast risetime for EMP simulation","authors":"H. Schilling, J. Schluter, M. Peters, K. Nielsen, J. T. Naff, H. Hammon","doi":"10.1109/PPC.1995.599806","DOIUrl":"https://doi.org/10.1109/PPC.1995.599806","url":null,"abstract":"The 1-MV EMP simulator at WWDBw, Munster, Germany, was developed during the late 1970s. The pulsed power system, supplied by Physics International Company (PI) of San Leandro, CA, includes a Marx generator and a peaking circuit/transmission line pulse launch system contained within a plastic housing (gas box) filled with the insulating gas R-12 (freon). Two major concerns have developed over the years since the WWDBw simulator was first dedicated: (1) the venting of freon-12 into the atmosphere is considered harmful to the natural environment, and (2) the most recent EMP studies show that simulated field risetimes might need to be considerably faster than the 10 ns requirements of ten years ago. WWDBw has contracted with PI to provide modifications as necessary to eliminate R-12 from the gas house and to design and develop a pulser providing faster risetimes. PI's modifications have achieved reliable, reproducible operation at 970 kV in an air environment with risetimes less than 7 ns. In addition, PI has designed, fabricated and tested a pulser for risetimes of 1 ns, 300 to 500 kV output voltage, and 30 to 100 ns pulsewidth. The pulser is compatible with the 1 MV pulser interface so that either pulser can be used to drive the 90 /spl Omega/ waveguide. The fast risetime pulser uses the existing Marx to charge a transfer capacitor similar to the existing peaking capacitors. Upon closure of the transfer switch, a very low inductance peaking capacitor is charged. Subsequent closure of a low inductance output switch launches the fast risetime wave.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"41 1","pages":"1359-1364 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76107763","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. Mazzola, M. Grothaus, M. Walch, J. Jones-Meehan
{"title":"New electrical control methods to prevent power plant fouling","authors":"M. Mazzola, M. Grothaus, M. Walch, J. Jones-Meehan","doi":"10.1109/PPC.1995.596451","DOIUrl":"https://doi.org/10.1109/PPC.1995.596451","url":null,"abstract":"One new nonchemical method for removal of biofouling utilizes pulsed acoustic waves above the cavitation threshold to remove accumulated scale and/or biofouling from the inside walls of piping and other enclosed structures. The pulsed acoustic wave successively removes accumulated deposits as the arc-discharge source is moved down the tube by an operator. We describe a program developing a compact, portable tube-cleaning system for use in utility and US Navy scheduled plant maintenance. Results from a laboratory demonstration with typical heat-exchanger tubing taken from a Tennessee Valley Authority power plant are presented. In addition results from a field experiment conducted at the US Navy Marine Corrosion Test Facility, Ft. Lauderdale, Florida, are presented that demonstrated significant (order of magnitude) reduction in biofouling associated with pulsed acoustic shock wave treatment at intensities below the cavitation threshold.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"26 1","pages":"34-39 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80887772","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 new look at the energy efficiency of a series magnetic pulse compressor with resistive losses","authors":"N. Georgescu","doi":"10.1109/PPC.1995.599808","DOIUrl":"https://doi.org/10.1109/PPC.1995.599808","url":null,"abstract":"In high repetition rate magnetic pulse compressors, even small increases of energy efficiency are very important. In this paper, the energy efficiency in a magnetic pulse compression loop is defined as the ratio between the accumulated energy in the final capacitor (C2) and the initial energy in the first capacitor (C1). The maximization of the energy efficiency does not correspond to the total discharge of the first capacitor, such as others authors have stated. An expression for the energy efficiency (/spl epsi/), as a function of k=C1/C2, is demonstrated. The graphical representations show that the /spl epsi/ maximization is obtained for k>1, such that a progressively decrease of the capacitors in the compression chain is needed. The energy efficiency is in this case with up to 20% greater than that of the other theory. Another very important advantage of the authors' theory is demonstrated: the voltage level, remains practically unchanged all along the series magnetic pulse compression circuit.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"1 1","pages":"1371-1376 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82150954","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 fast capacitive voltage monitor for low impedance pulse lines","authors":"P. Choi, M. Favre","doi":"10.1109/PPC.1995.599723","DOIUrl":"https://doi.org/10.1109/PPC.1995.599723","url":null,"abstract":"Accurate and reliable electrical measurements are critical issues in high voltage transmission lines for pulse power generators. Capacitive voltage monitoring is a well established technique which is widely used in this type of device. The monitor can operate in the pure capacitive division, or self-integrating mode for direct monitoring of the voltage or as a Ddot probe to measure the time rate of change of voltage. Difficulties exist in trying to improve the high frequency response of these monitors in the environment of a low impedance pulse line with water dielectric. The ultimate goal in capacitive voltage monitoring is a simple design, with good high frequency response, convenient attenuation ratio and long time constant measurement capability. Here we propose a new design for a capacitive voltage monitor which, in principle, satisfies most of the above requirements and is particularly suitable when applied to low impedance high voltage transmission lines. Above all, the design is intrinsically matched to the characteristics of the output cable and simple to implement. In the following, the basic schemes of the capacitive monitor are first discussed in order to highlight the problems with high frequency design. The new design is then presented together with details of construction. Finally, the properties of the proposed monitor obtained from calculation, and circuit simulation are demonstrated.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"18 1","pages":"880-885 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72951454","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}
R. Focia, E. Schamiloglu, C. Fleddermann, W. Nunnally, J. Gaudet
{"title":"Ultrafast high power switching diodes","authors":"R. Focia, E. Schamiloglu, C. Fleddermann, W. Nunnally, J. Gaudet","doi":"10.1109/PPC.1995.596804","DOIUrl":"https://doi.org/10.1109/PPC.1995.596804","url":null,"abstract":"Impressive progress in semiconductor switch technology has been demonstrated at the A.I. Ioffe Physiotechnical Institute in St. Petersburg, Russia. In the moderate voltage (1 kV), moderate current (100 A) regime, the Ioffe group's technology demonstrates switching times of 2 ns or a di/dt of 5/spl times/10/sup 10/ A/s. In the thyristor area, large diameter devices have demonstrated rates of current rise approaching 10/sup 12/ A/s, which is comparable with spark gaps. A three year research project is underway in collaboration with the Ioffe group which seeks to define the physics, assess the technology, and identify the critical parameters that allow for successful development of semiconductor switches capable of operating at the parameters described above. The initial stage of the program studies individual switches produced by the Ioffe group in order to verify their operational parameters. The second stage of the program will study the physics issues important in achieving the operational specifications. The final stage of the program will suggest modifications to the device manufacture process that may yield further improvements in performance. This paper presents information on a computer-controlled test stand that was developed for testing a variety of components produced by the Ioffe group. Information on circuit modeling using PSPICE and one specific test circuit are discussed. Finally, performance results for two kinds of drift step recovery diodes (DSRD) are presented.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"2015 1","pages":"723-728 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76752368","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}
D.L. Smith, P. Ingwersen, L. Bennett, J. Boyes, D.E. Anderson, J. Greenly, R. Sudan, D. Hammer
{"title":"The COBRA accelerator pulsed-power driver for Cornell/Sandia ICF research","authors":"D.L. Smith, P. Ingwersen, L. Bennett, J. Boyes, D.E. Anderson, J. Greenly, R. Sudan, D. Hammer","doi":"10.1109/PPC.1995.599821","DOIUrl":"https://doi.org/10.1109/PPC.1995.599821","url":null,"abstract":"This paper introduces and describes the new Cornell Beam Research Accelerator, COBRA, the result of a three and one-half year collaboration. The flexible 4 to 5-MV, 100 to 250-kA, 46-ns pulse width accelerator is based on a four-cavity inductive voltage adder (IVA) design. In addition to being a mix of new and existing components, COBRA is unique in the sense that each cavity is driven by a single pulse forming line, and the IVA output polarity may be reversed by rotating the cavities 180/spl deg/ about their vertical axis. Our tests with negative high voltage on the inner MITL stalk indicate that the vacuum power flow has established reasonable azimuthal symmetry within about 2 ns (or 0.6 m) after the cavity output gap. Preliminary results with the accelerator, single cavity, and MITL are presented along with the design details and circuit model predictions.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"13 1","pages":"1449-1454 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84941150","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":"Field excitation and discharge switching for air-core compulsators","authors":"R. Thelen","doi":"10.1109/PPC.1995.596494","DOIUrl":"https://doi.org/10.1109/PPC.1995.596494","url":null,"abstract":"The Center for Electromechanics at The University of Texas (USA) has designed and built three generations of air-core compulsators for railgun power supply application. These systems rely on compact power electronics to provide rapid self-excitation of the field windings and control of the main current discharge. All three systems built so far have been single-phase armature machines. The parameters for these systems range from 20 to 42 kA field excitation at 125 to 400 Hz rectification and 2.5 to 12 kV. The main discharge peak current ranges from 0.3 to 3 MA. The design and performance of past switching systems is reviewed and the prospects for further mass and volume reductions is presented.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"14 1","pages":"286-291 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91489195","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. Jung, W. Mayerhofer, M. Edele, O. Gstir, T. Schweizer, E. Zeyfang, E. Ramezani
{"title":"Test of fast SCRs as spark gap replacement","authors":"M. Jung, W. Mayerhofer, M. Edele, O. Gstir, T. Schweizer, E. Zeyfang, E. Ramezani","doi":"10.1109/PPC.1995.596806","DOIUrl":"https://doi.org/10.1109/PPC.1995.596806","url":null,"abstract":"To replace the spark gaps in the PFNs of our pulsed high power CO/sub 2/ laser first investigations on fast SCRs have been made. We report our tests on stacked high current thyristors (HCT) as a closing switch at an 8 /spl mu/F capacitor bank with various resistor loads. The charged voltage per stack unit was up to 3.6 kV. At a peak current of 9 kA, we reached a maximum di/dt of 8 kA//spl mu/s. First tests on repetitive operations have been done. The results show the possibility to replace the spark gaps of our system by HCTs.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"9 1","pages":"729-732 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91531260","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}
G. Masten, I. Djachiachvili, D. B. Morris, J. Gahl
{"title":"Preliminary performance results of a high-current Cs-Ba tacitron in a simple inverter","authors":"G. Masten, I. Djachiachvili, D. B. Morris, J. Gahl","doi":"10.1109/PPC.1995.599712","DOIUrl":"https://doi.org/10.1109/PPC.1995.599712","url":null,"abstract":"A tacitron is a gas-discharge triode that is designed to be completely grid-controlled. Demountable cesium-barium (Cs-Ba) tacitrons have exhibited very low forward voltage drops in the range of a few volts, hold-off voltages greater than 200 V, and average conduction current densities greater than 10 A/cm/sup 2/. These characteristics yield an average power switching density on the order of 10/sup 3/ W/cm/sup 2/ in excess of 95% peak switching efficiency. This parameter regime places the Cs-Ba tacitron in the range of conventional solid-state devices, with the advantage that the tacitron should reliably operate in extremes of temperature and radiation. The intent of this investigation is to determine the feasibility of constructing a 6 kW continuous power inverter unit with a pair of high-current tacitrons.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"56 1 1","pages":"816-821 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91143733","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}
K. Lamppa, R. Stinnett, T. Renk, M. T. Crawford, John Greenly
{"title":"Active plasma source formation in the MAP diode","authors":"K. Lamppa, R. Stinnett, T. Renk, M. T. Crawford, John Greenly","doi":"10.1109/PPC.1995.596774","DOIUrl":"https://doi.org/10.1109/PPC.1995.596774","url":null,"abstract":"The ion beam surface treatment (IBEST) program is exploring using ion beams to treat the surface of a wide variety of materials. These experiments have shown that improved corrosion resistance. Surface hardening, grain size modification, polishing and surface cleaning can all be achieved using a pulsed 0.4-0.8 MeV ion beam delivering 1-10 J/cm/sup 2/. The magnetically-confined anode plasma (MAP) diode, developed at Cornell University, produces an active plasma which can be used to treat the surfaces of materials. The diode consists of a fast puff valve as the source of gas to produce the desired ions and two capacitively driven B-fields. A slow magnetic field is used for electron insulation and a fast field is used to both ionize the puffed gas and to position the plasma in the proper spatial location in the anode prior to the accelerator pulse. The relative timing between subsystems is an important factor in the effective production of the active plasma source for the MAP diode system. The MAP diode has been characterized using a Langmuir probe to measure plasma arrival times at the anode annulus for hydrogen gas. This data was then used to determine the optimum operating point for the MAP diode on RHEPP-1 accelerator shots. Operation of the MAP diode system to produce an ion beam of 500 kV, 12 kA with 40% efficiency (measured at the diode) has been demonstrated.","PeriodicalId":11163,"journal":{"name":"Digest of Technical Papers. Tenth IEEE International Pulsed Power Conference","volume":"56 1","pages":"649-654 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1995-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82051559","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}