K. Ware, R. Gullickson, J. Pierre, R. Schneider, I. Vitkovitsky
{"title":"Technologies for development of more affordable large X-ray simulators","authors":"K. Ware, R. Gullickson, J. Pierre, R. Schneider, I. Vitkovitsky","doi":"10.1109/PPC.1999.825462","DOIUrl":"https://doi.org/10.1109/PPC.1999.825462","url":null,"abstract":"Pulsed power conditioning elements between the energy-storing capacitor banks and the radiation loads have been the major cost driver for large simulators. The cost is driven by the pulsed power requirements needed to provide the necessary spectral and temporal characteristics of the radiation output for Nuclear Weapons Effects Testing (NWET), as well as for assuring efficient production of the radiation. During the past forty years, the Defense Threat Reduction Agency (DTRA) has developed pulsed power elements and systems that are lowering the cost of X-ray simulators. This paper discusses these technologies including capacitors, closing switches, water pulse lines, vacuum interfaces, plasma opening switches, and vacuum power flow.","PeriodicalId":11209,"journal":{"name":"Digest of Technical Papers. 12th IEEE International Pulsed Power Conference. (Cat. No.99CH36358)","volume":"178 1","pages":"264-270 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1999-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73934108","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. Spielman, W. Stygar, K. Struve, S. Rosenthal, M. Desjarlais, Michael R Douglas, J. Asay, C. Hall, M. Bernard, T. Gilliland, T. Wagoner
{"title":"Conductor energy losses at 10 MA/cm on Z","authors":"R. Spielman, W. Stygar, K. Struve, S. Rosenthal, M. Desjarlais, Michael R Douglas, J. Asay, C. Hall, M. Bernard, T. Gilliland, T. Wagoner","doi":"10.1109/PPC.1999.823684","DOIUrl":"https://doi.org/10.1109/PPC.1999.823684","url":null,"abstract":"Very high current generators are being developed to drive compact loads leading to conductors carrying very high current densities. Losses in conductors include resistive, magnetic field diffusion, pdV work, and material motion contributions. We have designed and executed experiments on Sandia's 100-ns rise time, 20 MA Z accelerator to quantify those losses at current densities reaching 10 MA/cm. In these experiments we delivered nearly 20 MA to both high-current density and low-current density short circuit loads. We used B-dot probes and VISAR techniques to measure the magnetic field near the load. A reduction in the delivered current of /spl sim/15% over the 20 MA peak current prediction made without resistive losses was observed. Comparisons of these data with radiation magneto-hydrodynamics codes (RMHD) are presented. Implications on the efficiency of next generation pulsed power drivers are discussed.","PeriodicalId":11209,"journal":{"name":"Digest of Technical Papers. 12th IEEE International Pulsed Power Conference. (Cat. No.99CH36358)","volume":"19 1","pages":"991-994 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1999-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86277163","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}
J. Maenchen, S. Cordova, J. Gustwiller, D.L. Johnson, P. Menge, I. Molina, C. Olson, S. Rosenthal, D. Rovang, O. Oliver, D. Welch, V. Bailey, I. Smith, D. Droemer, E. Hunt, G. Macleod, L. Woo
{"title":"Inductive voltage adder driven X-ray sources for hydrodynamic radiography","authors":"J. Maenchen, S. Cordova, J. Gustwiller, D.L. Johnson, P. Menge, I. Molina, C. Olson, S. Rosenthal, D. Rovang, O. Oliver, D. Welch, V. Bailey, I. Smith, D. Droemer, E. Hunt, G. Macleod, L. Woo","doi":"10.1109/PPC.1999.825465","DOIUrl":"https://doi.org/10.1109/PPC.1999.825465","url":null,"abstract":"Inductive voltage adder (IVA) accelerators were developed to provide high-current (100s of kA) power pulses at high voltage (up to 20 MV) using robust modular components. This architecture simultaneously resolves problems found in conventional pulsed and linear induction accelerators. A variety of high-brightness pulsed X-ray radiographic sources are needed from submegavolt to 16-MeV endpoints with greater source brightness (dose/spot/sup 2/) than presently available. We are applying IVA systems to produce very intense (up to 75 TW/cm/sup 2/) electron beams for these flash radiographic applications. The accelerator electromagnetic pulse is converted to a directed electron beam at the end of a self-magnetically insulated vacuum transmission line. The cantilevered cathode threading the accelerator cavities terminates in a small (l-mm diameter) needle, producing the electron beam which is transported to a grounded Bremsstrahlung converter within a strong (/spl sim/50 T) axial magnetic field. These systems produce mm-sized stable electron beams, yielding very intense X-ray sources. Detailed simulations of the electron beam generation, transport, and target interaction are presented along with scaling laws for the radiation production and X-ray spot size. Experimental studies confirm these simulations and show this reliable, compact, and inexpensive technology scales to 1000-R doses a meter from a mm-diameter source in 50 ns.","PeriodicalId":11209,"journal":{"name":"Digest of Technical Papers. 12th IEEE International Pulsed Power Conference. (Cat. No.99CH36358)","volume":"132 1","pages":"279-282 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1999-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88355774","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. Gunin, V. F. Landl, S. Korovin, G. Mesyats, V. Rostov
{"title":"Experimental studies of long-lifetime cold cathodes for high power microwave oscillators","authors":"A. Gunin, V. F. Landl, S. Korovin, G. Mesyats, V. Rostov","doi":"10.1109/PPC.1999.823644","DOIUrl":"https://doi.org/10.1109/PPC.1999.823644","url":null,"abstract":"Electron beam parameters and material consumption were measured for edge-type explosive-emission cathodes made from different materials, working in a BWO-based HPM source, at a large number of pulses. Most of the materials demonstrated several degradation of emission properties and decrease in microwave emission after 10/sup 4/-10/sup 6/ pulses. A graphite cathode demonstrated stabilization of its emission parameters after 10/sup 7/ pulses and successful operation during 10/sup 8/ pulses at a pulse repetition rate of 100-150 pps.","PeriodicalId":11209,"journal":{"name":"Digest of Technical Papers. 12th IEEE International Pulsed Power Conference. (Cat. No.99CH36358)","volume":"19 1","pages":"833-836 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1999-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77172260","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":"The thermohydraulic generator: a pulse power source of intense pressure pulses","authors":"W. Hartmann, J. Kieser, K. Rohde","doi":"10.1109/PPC.1999.823597","DOIUrl":"https://doi.org/10.1109/PPC.1999.823597","url":null,"abstract":"Intense pressure pulses, often focussed to form strong shockwaves, are used for a variety of medical and industrial applications. In this contribution, a new principle-the thermohydraulic generation of strong pressure (sound) pulses-is reported which promises a considerably extended lifetime. The energy efficiency is comparable to that of commercial shockwave sources based on the magnetodynamic principle. The underlying physics is that of the generation of strong thermoelastic waves in electrically conducting media, in particular in electrolytes, by direct ohmic heating with intense current pulses. A simplified model is discussed to describe the pressure amplitudes and the influence of the thermoacoustic properties of the electrolyte. The source is scalable over a large range, and is arbitrarily adaptable in its shape. Large-area plane waves with amplitudes of up to 5 MPa have been achieved, as well as a self-focusing geometry with peak pressures of over 70 MPa.","PeriodicalId":11209,"journal":{"name":"Digest of Technical Papers. 12th IEEE International Pulsed Power Conference. (Cat. No.99CH36358)","volume":"89 10","pages":"654-657 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1999-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91502207","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. J. Fulker, P. Winstanley, A.D. Case, S. Macgregor, R. Fouracre, F. A. Tuema
{"title":"The evolution of pulsed discharges over PTFE in the presence of various cover gases","authors":"D. J. Fulker, P. Winstanley, A.D. Case, S. Macgregor, R. Fouracre, F. A. Tuema","doi":"10.1109/PPC.1999.823705","DOIUrl":"https://doi.org/10.1109/PPC.1999.823705","url":null,"abstract":"The spatial structure and temporal evolution of surface discharges have been studied. The substrate was a sheet of PTFE that was 0.5 mm thick and the cover gas was argon or nitrogen. The surface discharges were capacitively coupled to an earth plane that was located on the underside of the substrate. High-speed digital photographs were taken of the surface discharge development and these have shown that the structure was dependent upon the gas type. Uniform discharges tended to form in argon whereas filamentary discharges were prominent in nitrogen. It was also found that the amount of energy stored in the external circuit capacitance influences the nature of the surface discharge by determining both its width and uniformity.","PeriodicalId":11209,"journal":{"name":"Digest of Technical Papers. 12th IEEE International Pulsed Power Conference. (Cat. No.99CH36358)","volume":"91 1","pages":"1071-1074 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1999-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72898225","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-frequency current modulation in a diode with a plasma cathode","authors":"Y. Krasik, J. Felsteiner, A. Rosenberg","doi":"10.1109/PPC.1999.823645","DOIUrl":"https://doi.org/10.1109/PPC.1999.823645","url":null,"abstract":"The authors present a study of the modulation at frequencies of hundreds of MHz of an electron beam (I/sub e//spl les/30 A, E/sub e//spl les/40 keV, /spl tau//sub p//spl les/35 /spl mu/s) produced by a plasma cathode. The plasma was prepared by a noncomplete discharge that was ignited by a driving pulse applied between the front strips and a solid rear electrode of a ferroelectric sample [BaTiO/sub 3/ or Pb(Zr,Ti)O/sub 3/]. Investigation of the plasma and the beam modulation properties and their dependence on the experimental parameters is presented. The results are discussed within the framework of electrons oscillating in the potential well created by the positively charged plasma having feedback coupling with the input cable.","PeriodicalId":11209,"journal":{"name":"Digest of Technical Papers. 12th IEEE International Pulsed Power Conference. (Cat. No.99CH36358)","volume":"41 1","pages":"837-840 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1999-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77549273","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. Schamiloglu, G. Park, V. S. Soualian, C. Abdallah, Frank Hegeler
{"title":"Advances in the control of a \"smart tube\" high power backward wave oscillator","authors":"E. Schamiloglu, G. Park, V. S. Soualian, C. Abdallah, Frank Hegeler","doi":"10.1109/PPC.1999.823649","DOIUrl":"https://doi.org/10.1109/PPC.1999.823649","url":null,"abstract":"Previous accomplishments pertaining to the control of various parameters of an intense beam-driven relativistic backward wave oscillator (BWO) include maintaining a specified or desired output power over a determined frequency bandwidth, and maintaining a constant frequency over a wide range of power. This was accomplished using an iterative learning control (ILC) algorithm that yielded the appropriate input variables for the electron beam, as well as the appropriate displacement of the slow wave structure from the cutoff neck. A problem of much greater complexity is the simultaneous control of both frequency and power, involving the independent mapping of both power and frequency dependence on the two input variables: cathode voltage and slow wave structure displacement. The resultant two-variable system has been successfully implemented and tested for convergence with minimal iterations. In this paper we present an overview of our \"smart tube,\" its development, and our most recent results.","PeriodicalId":11209,"journal":{"name":"Digest of Technical Papers. 12th IEEE International Pulsed Power Conference. (Cat. No.99CH36358)","volume":"94 1","pages":"852-855 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1999-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78055725","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":"The parameters and energy amplification of compression generator with iron-free rotor defined by the magnetic field simulation","authors":"V. Chemerys, Y. Vaskovsky","doi":"10.1109/PPC.1999.825504","DOIUrl":"https://doi.org/10.1109/PPC.1999.825504","url":null,"abstract":"The paper contains the further consideration of the idea to use the rotating pulsed generator with iron-free rotor which was discussed briefly in the poster presented on the IEEE Pulsed Power Conference 1997 and in the poster of 8th EML 1997, both not published. The estimations made previously with application of both mathematic simulation and measurements on the small laboratory model have yielded low coefficient of total inductance variation (on the level 10-15 instead of 300-400 and more for completely iron machines). Now the modeling of a bigger sample of generator is done with the following dimensions: rotor diameter 0.25 m, active length 0.425 m and rotation frequency 6000 rpm. The results have enabled the possibility to reach the value of this coefficient near 120 at the increased density of initial magnetic energy for excitation in the space occupied by the rotor, equal to 1.6 MJ/m/sup 3/, and increased volume of the excitation field. The output energy in the ohmic load of the generator considered is equal to 2.14 MJ, what is near 34% of peak total magnetic energy.","PeriodicalId":11209,"journal":{"name":"Digest of Technical Papers. 12th IEEE International Pulsed Power Conference. (Cat. No.99CH36358)","volume":"116 1","pages":"437-440 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1999-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77086714","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. Li, U. Czok, A. Kalimov, M. Winkler, H. Wollnik
{"title":"Magnetic quadrupole lenses with (dB/dr)/sub max/>1000 T/m","authors":"G. Li, U. Czok, A. Kalimov, M. Winkler, H. Wollnik","doi":"10.1109/PPC.1999.823692","DOIUrl":"https://doi.org/10.1109/PPC.1999.823692","url":null,"abstract":"For the focusing of pulsed ion beams of high rigidity, new pulsed magnetic quadrupole lenses have been developed. To reach high flux densities, these quadrupole lenses were built as optimized steel-free devices. Up to now, a flux density above 12 T has been reached in a quadrupole of 22 mm aperture. This value is higher than values reached in superconducting or pulsed plasma lenses.","PeriodicalId":11209,"journal":{"name":"Digest of Technical Papers. 12th IEEE International Pulsed Power Conference. (Cat. No.99CH36358)","volume":"26 1","pages":"1022-1024 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1999-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77558583","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}