Conference Record of the Twenty-Fifth International Power Modulator Symposium, 2002 and 2002 High-Voltage Workshop.最新文献

{"title":"A new modulator controller of the PLS linac","authors":"S.C. Kim, S. Park, S.H. Kim, Y. Han, S. Nam","doi":"10.1109/MODSYM.2002.1189477","DOIUrl":"https://doi.org/10.1109/MODSYM.2002.1189477","url":null,"abstract":"The 2-GeV electron linac at Pohang accelerator laboratory (PAL) has been operated continuously as a full energy injector for the Pohang Light Source (PLS) since Dec. 1994. There have been continuous efforts to improve the klystron-modulator (K&M) system to make it more stable and reliable. To improve self-diagnostic, operation, monitoring, and remote communication, we developed a new modulator controller based on an industrial PC platform. The modulator controller mainly consisted of an interlock signal conditioning module, a fast pulse signal-conditioning module, and the main PC platform. Operating system of the PC is Windows NT 4.0, and application software is developed with C++. The interlock signal-conditioning module generally carries digital and slowly varying clean analog signals. The fast pulse signal-conditioning module is used for preconditioning fast pulse and DC signals that inherently have high noise levels, such signals as a beam voltage, a beam current, an EOLC current, a HVDC voltage, and a HVDC current. All operation data of the K&M system can be acquired and saved in real time. We are upgrading the main PLS, control system with EPICS. The industrial PC platform will function as an input/output controller (IOC) in the future EPICS PLS control system.","PeriodicalId":339166,"journal":{"name":"Conference Record of the Twenty-Fifth International Power Modulator Symposium, 2002 and 2002 High-Voltage Workshop.","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127351462","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":"Energy trapping and adaptive clocking innovations applied to capacitor charging series resonant inverters","authors":"J. O'Loughlin, J. Lehr, D. Loree","doi":"10.1109/MODSYM.2002.1189434","DOIUrl":"https://doi.org/10.1109/MODSYM.2002.1189434","url":null,"abstract":"The charging of a capacitive energy store is commonly accomplished by means of a high frequency series resonant switching inverter. A small amount of energy is switched each cycle but only a fraction is actually transferred to the store during the first portion of the charging process. The series resonant inverter behaves as a current source; and a constant amount of charge is delivered to the capacitor store each switching cycle. During the first portion of the charging process, the voltage on the store is low and the power or energy transfer is small compared to the constant volt-ampere capacity of the circuit. That is, there is a low power factor or impedance mismatch. During the switching cycle, there is an initial transfer of energy from the power source through the switching circuit; however, only a small portion of the energy stays in the capacitor store. The remainder flows back to the source and is then recycled again during the next switching cycle. Therefore, to transfer a given energy to the store requires the processing of a large amount of reactive power. By introducing an \"energy trap\" innovation to the circuit, the initial energy is forced to transfer to the store. The time required for this forced transfer to occur depends upon the voltage on the store. The transfer time is long when the voltage is low and decreases as the voltage increases. Since a new switching cycle cannot be initiated until the energy transfer of the present cycle is completed, the switching frequency must be chirped to match the circuit state as the charging process proceeds. An \"adaptive clocking innovation\" is used to monitor the energy transfer process and to clock the beginning of the next switching cycle when the energy transfer is completed. The result is a lower over-all switching frequency with lower losses for the same total energy transfer to the load. Since the circuit operates at a lower frequency at the beginning of the charging process one may be concerned that it would force the transformer size to increase. This is not the case because the transformer is working at a lower voltage during the low frequency part of the charging process and this combination of frequency and voltage results in a constant transformer flux and a lower over-all core loss.","PeriodicalId":339166,"journal":{"name":"Conference Record of the Twenty-Fifth International Power Modulator Symposium, 2002 and 2002 High-Voltage Workshop.","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127356844","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":"Outline of power modulator work supported by DOE SBRI grants","authors":"R. Koontz","doi":"10.1109/MODSYM.2002.1189478","DOIUrl":"https://doi.org/10.1109/MODSYM.2002.1189478","url":null,"abstract":"Each year, the Department of Energy funds grants for development of ideas in a variety of topics, some of which are associated with power modulator research. An initial Phase I grant allows the proposed research to be fleshed out with some preliminary hardware testing, and sets up the Phase II application which, if approved, funds the main research. For several years, various aspects of solid-state modulators have been the subjects of these grants. The renewed interest in gridded high power klystron designs has called for the development of new pulsed energy delivery systems that are not strictly modulators, but perform the same functions. This presentation reviews the status of presently funded SBIR grants that involve power modulator concepts or supporting component development, and gives a synopsis of the awards for 2002.","PeriodicalId":339166,"journal":{"name":"Conference Record of the Twenty-Fifth International Power Modulator Symposium, 2002 and 2002 High-Voltage Workshop.","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125054886","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":"Feasibility study of an explosively formed transient antenna","authors":"A. Neuber, N. Schoeneberg, J. Dickens, M. Kristiansen","doi":"10.1109/MODSYM.2002.1189493","DOIUrl":"https://doi.org/10.1109/MODSYM.2002.1189493","url":null,"abstract":"The feasibility of utilizing the chemical energy stored in high explosives to generate an antenna capable of radiating for several microseconds is studied. Crucial parameters such as conductivity as a function of time, maximum achievable antenna length for given initial device volume and weight, and material dependence are assessed by sub microsecond optical and electrical diagnostics. By utilizing a rotating framing mirror camera with up to 4 Megaframes per second, which produces a color image sequence consisting of 125 frames, possible premature breakup of the transient antenna rod is measured with adequate spatial and temporal resolution, thus revealing a rod growth velocity of a few millimeters/microsecond. Electrical diagnostic, primarily aimed at the conductivity between selected points along the rod propagation, enables to make a connection with the observed behavior based on the optical diagnostics. Maintaining electrical contact at the base of the device while the rod is fully formed is crucial and will be discussed in detail.","PeriodicalId":339166,"journal":{"name":"Conference Record of the Twenty-Fifth International Power Modulator Symposium, 2002 and 2002 High-Voltage Workshop.","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121521783","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":"Application of intense pulsed ion beam to materials processes","authors":"K. Masugata, K. Takao, M. Shiotani, T. Honda, R. Tejima, I. Kitamura, T. Takahashi","doi":"10.1109/MODSYM.2002.1189538","DOIUrl":"https://doi.org/10.1109/MODSYM.2002.1189538","url":null,"abstract":"Intense pulsed ion beams (PIB) are expected to be applied to material processes since they have unique features. To apply the PIB to materials processing two types of beam sources are considered, i.e. plasma focus (PF) and pulsed power ion diode. In the PF experiment Mather type electrode was used with a capacitor bank of 43.2 /spl mu/F. When PF was pre-filled with H/sub 2/ (250 Pa), ion current density (J/sub i/) of 0.65 kA/cm/sub 2/ was obtained at 40 cm downstream from the anode top. From the Thomson parabola spectrometer (TPS) measurement, protons of energy in the range of 0.1-1 MeV were observed. For the case of using mixture of H/sub 2/ (180 Pa) and N/sub 2/ (20 Pa), J/sub i/ was 1.1 kA/cm/sup 2/ and by the TPS protons and variety of nitrogen ions (N/sup (1-5+)/) of energy in the range of 0.4-6 MeV were observed. In the development of pulsed power ion diode, gas puff plasma gun is used as an ion source to produce nitrogen ion beam. In the preliminary experiment Ji of 1 A/cm/sup 2/ was obtained. We are now evaluating the characteristics of the ion diode and the accelerated ion beam. To evaluate the irradiation effect on materials, amorphous silicon films were irradiated by the ion beam produced by PF and we see that amorphous silicon layers are crystallized.","PeriodicalId":339166,"journal":{"name":"Conference Record of the Twenty-Fifth International Power Modulator Symposium, 2002 and 2002 High-Voltage Workshop.","volume":"27 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120891102","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":"Analysis of a railgun capacitor-muzzle-shunt energy recovery scheme","authors":"J. Bernardes, G. Lacava, M. J. Schrader","doi":"10.1109/MODSYM.2002.1189486","DOIUrl":"https://doi.org/10.1109/MODSYM.2002.1189486","url":null,"abstract":"A large fraction of the energy initially stored in a railgun pulsed power system normally remains in the circuit when the projectile exits. This residual energy, much of it stored in the barrel inductance, can be close to 50% of the initially stored energy. This is the result of significant current flowing in the projectile armature when the projectile exits the barrel. Muzzle shunts are designed to manage this residual current and energy, and as a result reduce or eliminate muzzle flash. To date, resistive and inductive muzzle shunts have been proposed and implemented. Resistive shunts can dissipate a majority of the residual energy in addition to preventing muzzle flash. Inductive-shunt schemes have been proposed as a means to recover the residual energy in a pulsed-alternator pulsed-power system. This paper describes a different muzzle-shunt approach; a capacitor shunt that is used to recover a large portion of the residual energy. This muzzle shunt is used in conjunction with a capacitor-based pulsed-power system, where one of the capacitor bank sections is used both as the shunt element as well as the recovered-energy storage element. Results are presented of an analysis of this scheme using a transient circuit model of a representative railgun circuit.","PeriodicalId":339166,"journal":{"name":"Conference Record of the Twenty-Fifth International Power Modulator Symposium, 2002 and 2002 High-Voltage Workshop.","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127097955","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":"Small-size pulsed lasers in medical applications","authors":"M. Iberler, K. Frank","doi":"10.1109/MODSYM.2002.1189553","DOIUrl":"https://doi.org/10.1109/MODSYM.2002.1189553","url":null,"abstract":"The application of physics concepts to solve biological and medical problems are of growing interest. There are strong efforts to study the use of pulsed laser system in medical applications like dermatology, surgery, dental medicine and ophthalmology. Laser wavelengths cover a wide range from the ultraviolet to the far infrared. The most common radiation sources include all kind of lasers like solid-state lasers, semiconductor lasers and also gas discharge lasers. The important requirement on the choice of the type with regard to its wavelength is the biological response of the treated tissue. The presentation gives a short introduction about the principles of different pulsed laser systems for medical application. The following part of this presentation is devoted to discuss modulator design pulse shaping methods and applications of different laser systems mainly employed for ophthalmology. A lot of effort has gone into ophthalmology to adapt pulsed laser systems for applications like photo refractive ceractomy or LASIK for substituting glasses, retina coagulation and last but not least the cataract ablation as most common surgery.","PeriodicalId":339166,"journal":{"name":"Conference Record of the Twenty-Fifth International Power Modulator Symposium, 2002 and 2002 High-Voltage Workshop.","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133659227","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 Coulomb transfer pseudo-spark switch","authors":"S. Park, Y. Han, Sang Hee Kim, Y. Kwon, S.H. Kim, Y.J. Park, S. Nam","doi":"10.1109/MODSYM.2002.1189456","DOIUrl":"https://doi.org/10.1109/MODSYM.2002.1189456","url":null,"abstract":"In realizing electro-magnetic launchers, one of key components is a switch that can transfer high energy to a load and also has a precise triggering capability. The pseudo-spark switch is a good candidate to such applications. Various designs of the pseudo-spark switch had been tested at different institutes for high-energy transfer, but not high enough to fulfill specifications of the launcher experiment. To adopt required specifications of the launcher that are 20 kV nominal hold-off voltage, 150 kA peak current, /spl sim/1 ms pulse-width, and /spl sim/ 1,000 shot lifetime, a pseudo-spark switch is designed and fabricated. A high dielectric surface discharge trigger unit is employed in the switch. Two different pseudo-spark switch geometries are fabricated and tested. One has hollow anode and hollow cathode with axially symmetric ring slit bore hole channels. Another has radial hollow anode and cathode with multi-channel bore holes. All electrodes are made of stainless steel. A maximum 100 kJ capacitor bank is used to test coulomb transfer capability of the switch. The 100 kJ capacitor bank is consisted of two parallel-connected 50 /spl mu/F, 45 kV capacitors. Helium and argon are used in the switch test at different pressure ranges.","PeriodicalId":339166,"journal":{"name":"Conference Record of the Twenty-Fifth International Power Modulator Symposium, 2002 and 2002 High-Voltage Workshop.","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114406483","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":"EMC and failure mode issues in dielectrics: an update","authors":"W. J. Sarjeant, J. Zirnheld, K. Burke, I. Kohlberg, G. Blaise","doi":"10.1109/MODSYM.2002.1189555","DOIUrl":"https://doi.org/10.1109/MODSYM.2002.1189555","url":null,"abstract":"Electrical breakdown has been of interest in the areas of energy storage in dielectrics and the aging of capacitors and insulators for a long time. More recently, however, the generation of electromagnetic fields in the external environment by the breakdown process has been receiving attention because of the increased susceptibility of microelectronic components (e.g., VLSI) to unwanted electromagnetic fields. In this presentation Electromagnetic Compatibility (EMC) issues in modem high-density electronics are addressed through a new theory that seeks to explain that sudden energy releases are possible, even in powered-down states of systems, which could create erroneous or misleading internal signals in such systems. This theory introduces the concept of localized stored energy at defects within insulating and semi-insulating materials that make up modem electronics. Experimental validation of these effects, just recently demonstrated, will be presented in the context of this, work in progress.","PeriodicalId":339166,"journal":{"name":"Conference Record of the Twenty-Fifth International Power Modulator Symposium, 2002 and 2002 High-Voltage Workshop.","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114929138","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":"Interaction of rapid magnetic fields with plasmas and implications to pulsed-power systems","authors":"R. Arad, A. Weingarten, K. Tsigutkin, Y. Ralchenko, D. Osin, Y. Maron, A. Fruchtman, N. Chakrabarti, R. Commisso, B. Weber","doi":"10.1109/MODSYM.2002.1189419","DOIUrl":"https://doi.org/10.1109/MODSYM.2002.1189419","url":null,"abstract":"The behavior of rapidly rising magnetic fields decisively affects the operation of plasma opening switches, high-power transmission lines, and particle-beam diodes. Here, we describe recently observed novel phenomena in the interaction of magnetic fields with plasmas in such systems. The understanding of the underlying physics is used to design and optimize plasma opening switches and their coupling to loads. High-resolution spectroscopic methods, with the aid of plasma doping techniques, were used to obtain the time-dependent 2-D distributions of the magnetic field, ion velocities, electron density, and electron energy distribution. The results showed simultaneous rapid magnetic field penetration and plasma reflection accompanied by ion-species separation [A. Weingarten et. al., Phys. Rev. Lett. 87, 115004 (2001)]. These phenomena strongly modify the plasma dynamics, thereby influencing the effective switch impedance and the resultant coupling of the power to the load. The current conduction and switch operation are also found to be highly influenced by the electron density distribution and plasma composition. Possible ways to improve the system operation, brought about by these findings, are suggested.","PeriodicalId":339166,"journal":{"name":"Conference Record of the Twenty-Fifth International Power Modulator Symposium, 2002 and 2002 High-Voltage Workshop.","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114781900","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}