Pub Date : 2019-06-01DOI: 10.1109/PPPS34859.2019.9009784
H. Yamashita, Y. Torigoe, D. Wang, T. Namihira
Non-thermal plasma generated by pulsed discharge is expected to efficiently treat combustion exhaust gases such as nitrogen oxide (NOx) and sulfur oxide (SOx) due to its high chemical activity. Nanosecond pulsed discharge which has voltage rise time and fall time of 2 ns, pulse width 5 ns and peak value of 60 kV, has been developed by our group. Nanosecond pulsed discharge mainly consists of streamer discharge phase, so that heat loss which caused by glow discharge is less, and plasma impedance is kept almost constant during the streamer discharge phase. Therefore, impedance matching between pulsed power supply and discharge load is possible. Applications on ozone generation and NO treatment using nanosecond pulsed discharge are reported with high energy efficiency compared to other discharge methods. However, the discharge mode transit to arc discharge phase sometimes. Also, for industrial applications, the plasma processing capacity leaves room to improve. It has also been reported that negative polarity nanosecond pulse discharges give better results depending on the plasma processing applications. In this study, negative polarity DC superimposed nanosecond pulsed discharge was suggested in order to improve the better performance of the nanosecond discharge plasma. Results of ozone generation using negative polarity DC superimposed nanosecond pulsed discharge have also been introduced.
{"title":"Characteristics of negative-polarity DC superimposed nanosecond pulsed discharge and its applications","authors":"H. Yamashita, Y. Torigoe, D. Wang, T. Namihira","doi":"10.1109/PPPS34859.2019.9009784","DOIUrl":"https://doi.org/10.1109/PPPS34859.2019.9009784","url":null,"abstract":"Non-thermal plasma generated by pulsed discharge is expected to efficiently treat combustion exhaust gases such as nitrogen oxide (NOx) and sulfur oxide (SOx) due to its high chemical activity. Nanosecond pulsed discharge which has voltage rise time and fall time of 2 ns, pulse width 5 ns and peak value of 60 kV, has been developed by our group. Nanosecond pulsed discharge mainly consists of streamer discharge phase, so that heat loss which caused by glow discharge is less, and plasma impedance is kept almost constant during the streamer discharge phase. Therefore, impedance matching between pulsed power supply and discharge load is possible. Applications on ozone generation and NO treatment using nanosecond pulsed discharge are reported with high energy efficiency compared to other discharge methods. However, the discharge mode transit to arc discharge phase sometimes. Also, for industrial applications, the plasma processing capacity leaves room to improve. It has also been reported that negative polarity nanosecond pulse discharges give better results depending on the plasma processing applications. In this study, negative polarity DC superimposed nanosecond pulsed discharge was suggested in order to improve the better performance of the nanosecond discharge plasma. Results of ozone generation using negative polarity DC superimposed nanosecond pulsed discharge have also been introduced.","PeriodicalId":103240,"journal":{"name":"2019 IEEE Pulsed Power & Plasma Science (PPPS)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121071247","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}
Pub Date : 2019-06-01DOI: 10.1109/PPPS34859.2019.9009758
R. Lee, E. Tucker, A. Neuber, A. Hewitt, R. Clark, H. Hudyncia, T. Buntin, D. Barnett, J. Dickens, J. Mankowski, W. A. Harrison
The impact of mechanical stresses on polymer bonded high explosives, HE, is investigated. High-Speed photography in the visible spectrum, VIS, as well as mid-wave infrared (MWIR) of HE during small diameter drilling and controlled skidding is presented. Controlled drilling into the HE enables recording the size and temperature of shavings under varying feed and speeds. Even at very high drill speeds, the HE phase transition temperature of approx. 180 degree Celsius is rarely exceeded. The MWIR signals radiated are recorded with FLIR's X6901sc High-speed MWIR camera, which uses InSb technology, with a wavelength range from 3.0 to 5.0 µm, and up to 1,004 fps at a resolution of 640 × 512 in the temperature range of interest. High-speed recording in the visible is obtained utilizing Phantom's VEO710s high-speed camera at a higher frame rate of 7,400 fps at a resolution of 1280 × 800 in the VIS. Observing the HE-grit interaction in the MWIR poses a great challenge, for IR is blocked by many glasses.
{"title":"High-Speed Imaging of Polymer-Bonded Explosives under Mechanical Stresses","authors":"R. Lee, E. Tucker, A. Neuber, A. Hewitt, R. Clark, H. Hudyncia, T. Buntin, D. Barnett, J. Dickens, J. Mankowski, W. A. Harrison","doi":"10.1109/PPPS34859.2019.9009758","DOIUrl":"https://doi.org/10.1109/PPPS34859.2019.9009758","url":null,"abstract":"The impact of mechanical stresses on polymer bonded high explosives, HE, is investigated. High-Speed photography in the visible spectrum, VIS, as well as mid-wave infrared (MWIR) of HE during small diameter drilling and controlled skidding is presented. Controlled drilling into the HE enables recording the size and temperature of shavings under varying feed and speeds. Even at very high drill speeds, the HE phase transition temperature of approx. 180 degree Celsius is rarely exceeded. The MWIR signals radiated are recorded with FLIR's X6901sc High-speed MWIR camera, which uses InSb technology, with a wavelength range from 3.0 to 5.0 µm, and up to 1,004 fps at a resolution of 640 × 512 in the temperature range of interest. High-speed recording in the visible is obtained utilizing Phantom's VEO710s high-speed camera at a higher frame rate of 7,400 fps at a resolution of 1280 × 800 in the VIS. Observing the HE-grit interaction in the MWIR poses a great challenge, for IR is blocked by many glasses.","PeriodicalId":103240,"journal":{"name":"2019 IEEE Pulsed Power & Plasma Science (PPPS)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124930875","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}
Pub Date : 2019-06-01DOI: 10.1109/PPPS34859.2019.9009893
C. Grabowski, J. Santillanes, A. Shay, B. Smart, G. Tilley, K. Tunell, N. Joseph, S. Coffey, G. Archuleta, E. Gutierrez, B. Hughes, J. Lott, R. Natal, I. Owens
HERMES III is a 20-MeV linear induction accelerator that was constructed at Sandia National Laboratories in the late 1980's and continues operation to this day. The accelerator utilizes 10 Marx banks for its initial energy storage and pulse formation. These Marx banks discharge their energy into 20 intermediate storage capacitors which, in turn, feed 80 pulse forming lines that further condition the pulse. Transmission line feeds from the pulse forming lines then deliver the electrical energy to 20 induction cavities arrayed along the axis of the machine to build the final output pulse along a central magnetically insulated transmission line (MITL). There are two triggering systems within the accelerator that work together in this energy discharge process. One simultaneously triggers the initial discharge of energy from each of the 10 Marx banks; the other staggers the triggering of the Rimfire gas switches following each intermediate storage capacitor so as to properly synchronize the energy delivery to the downstream cavities and the MITL with the pulse propagation along the MITL. Until recently, these triggering systems were the original systems dating back to the initial commissioning of the accelerator, however both have now been replaced with new and more modernized systems. Design details for both triggering systems will be presented, along with an overview of some of the initial operational data from the HERMES III accelerator using these new triggering systems.
{"title":"Modernization of the Marx and Rimfire Triggering Systems for the HERMES-III Accelerator","authors":"C. Grabowski, J. Santillanes, A. Shay, B. Smart, G. Tilley, K. Tunell, N. Joseph, S. Coffey, G. Archuleta, E. Gutierrez, B. Hughes, J. Lott, R. Natal, I. Owens","doi":"10.1109/PPPS34859.2019.9009893","DOIUrl":"https://doi.org/10.1109/PPPS34859.2019.9009893","url":null,"abstract":"HERMES III is a 20-MeV linear induction accelerator that was constructed at Sandia National Laboratories in the late 1980's and continues operation to this day. The accelerator utilizes 10 Marx banks for its initial energy storage and pulse formation. These Marx banks discharge their energy into 20 intermediate storage capacitors which, in turn, feed 80 pulse forming lines that further condition the pulse. Transmission line feeds from the pulse forming lines then deliver the electrical energy to 20 induction cavities arrayed along the axis of the machine to build the final output pulse along a central magnetically insulated transmission line (MITL). There are two triggering systems within the accelerator that work together in this energy discharge process. One simultaneously triggers the initial discharge of energy from each of the 10 Marx banks; the other staggers the triggering of the Rimfire gas switches following each intermediate storage capacitor so as to properly synchronize the energy delivery to the downstream cavities and the MITL with the pulse propagation along the MITL. Until recently, these triggering systems were the original systems dating back to the initial commissioning of the accelerator, however both have now been replaced with new and more modernized systems. Design details for both triggering systems will be presented, along with an overview of some of the initial operational data from the HERMES III accelerator using these new triggering systems.","PeriodicalId":103240,"journal":{"name":"2019 IEEE Pulsed Power & Plasma Science (PPPS)","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126186829","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}
Pub Date : 2019-06-01DOI: 10.1109/PPPS34859.2019.9009748
R. Shapovalov, M. Adams, M. Evans, H. Hasson, J. Young, I. West-Abdallah, P. Gourdain
X pinches are well-known sources for point-projection radiography: given the right conditions, they generate very bright, x-ray bursts launched from a very small, dense plasma source. To improve the performance of x pinches, a compact pulser was built at the University of Rochester. The pulser is simplified Linear Transformer Driver: it consists of 5 LTD bricks (which is two capacitors and high-current switch all are connected in series) directly coupled to the transmission line, with bricks hanging from the transmission line rather than positioned radially outward, as it is the case in usual LTD designs. The pulser can store up to 4-kJ of initial energy when charged to ±100 kV, and simulations predict it can deliver up to 300-kA of peak current into an inductive x-pinch load with less than 150-ns time-to-peak. In this paper we present short-circuit measurements of the pulser. The load is 2.54-cm-long, 9.6-cm-diameter metal cylinder installed in the anode-cathode gap with inductance of only 1.13 nH. The current oscillations into this load allow us to directly measure the driver internal inductance and resistance. The data is compared to the Screamer simulations.
{"title":"Low-Inductance Load Test of a New 250-Ka, 150-Ns Pulser for Fast X-Pinch Sources","authors":"R. Shapovalov, M. Adams, M. Evans, H. Hasson, J. Young, I. West-Abdallah, P. Gourdain","doi":"10.1109/PPPS34859.2019.9009748","DOIUrl":"https://doi.org/10.1109/PPPS34859.2019.9009748","url":null,"abstract":"X pinches are well-known sources for point-projection radiography: given the right conditions, they generate very bright, x-ray bursts launched from a very small, dense plasma source. To improve the performance of x pinches, a compact pulser was built at the University of Rochester. The pulser is simplified Linear Transformer Driver: it consists of 5 LTD bricks (which is two capacitors and high-current switch all are connected in series) directly coupled to the transmission line, with bricks hanging from the transmission line rather than positioned radially outward, as it is the case in usual LTD designs. The pulser can store up to 4-kJ of initial energy when charged to ±100 kV, and simulations predict it can deliver up to 300-kA of peak current into an inductive x-pinch load with less than 150-ns time-to-peak. In this paper we present short-circuit measurements of the pulser. The load is 2.54-cm-long, 9.6-cm-diameter metal cylinder installed in the anode-cathode gap with inductance of only 1.13 nH. The current oscillations into this load allow us to directly measure the driver internal inductance and resistance. The data is compared to the Screamer simulations.","PeriodicalId":103240,"journal":{"name":"2019 IEEE Pulsed Power & Plasma Science (PPPS)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125331429","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}
Pub Date : 2019-06-01DOI: 10.1109/PPPS34859.2019.9009907
F. S. Yamasaki, J. O. Rossi, Leandro C. Silva, E. Rangel, E. Schamiloglu
A growing interest has been raising around the use of nonlinear transmission lines (NLTLs) for radiofrequency (RF) generation since recent results published has demonstrated great prospects for this application. The subject of this paper is about a continuous ferrite loaded nondispersive line known as a gyromagnetic nonlinear transmission line (GNLTL), biased by an axial magnetic field. This type of transmission line has demonstrated a high RF conversion efficiency (up to 20.0%), showing a good capability of operation in a broader frequency range, between 300 MHz and 6.0 GHz. Several authors used different approaches to study the gyromagnetic effect to understand the precession movement of the ferrite magnetic dipoles. The model proposed and studied here to analyze the GNLTL has a coaxial structure using NiZn ferrite beads distributed in a 20-cm coaxial line at a high voltage operation. Signal results were compared to check the influence of a solenoid on the axial magnetic bias. This paper explores the oscillations generated at the output caused by the changes in the magnetic system setup. It is expected that the discussion presented here will be useful as a basis to develop a new system capable of generating RF for mobile defense platforms.
{"title":"Operation of a Gyromagnetic Line with Magnetic Axial Bias","authors":"F. S. Yamasaki, J. O. Rossi, Leandro C. Silva, E. Rangel, E. Schamiloglu","doi":"10.1109/PPPS34859.2019.9009907","DOIUrl":"https://doi.org/10.1109/PPPS34859.2019.9009907","url":null,"abstract":"A growing interest has been raising around the use of nonlinear transmission lines (NLTLs) for radiofrequency (RF) generation since recent results published has demonstrated great prospects for this application. The subject of this paper is about a continuous ferrite loaded nondispersive line known as a gyromagnetic nonlinear transmission line (GNLTL), biased by an axial magnetic field. This type of transmission line has demonstrated a high RF conversion efficiency (up to 20.0%), showing a good capability of operation in a broader frequency range, between 300 MHz and 6.0 GHz. Several authors used different approaches to study the gyromagnetic effect to understand the precession movement of the ferrite magnetic dipoles. The model proposed and studied here to analyze the GNLTL has a coaxial structure using NiZn ferrite beads distributed in a 20-cm coaxial line at a high voltage operation. Signal results were compared to check the influence of a solenoid on the axial magnetic bias. This paper explores the oscillations generated at the output caused by the changes in the magnetic system setup. It is expected that the discussion presented here will be useful as a basis to develop a new system capable of generating RF for mobile defense platforms.","PeriodicalId":103240,"journal":{"name":"2019 IEEE Pulsed Power & Plasma Science (PPPS)","volume":"180 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115459225","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}
Pub Date : 2019-06-01DOI: 10.1109/PPPS34859.2019.9009953
M. Belhaj, S. Dadouch
Charging of dielectric materials under electron irradiation is a commonly encountered problem in many space applications. Spacecraft charging due to solar and cosmic radiations may lead to critical discharge phenomenon. Indeed, under irradiation (especially electron irradiation), insulators as well as floating conductors may charge negatively or positively depending on the incident electron properties (energy, incidence angle, flux) and on the specific material properties (composition, surface roughness, contamination, temperature, etc.) The knowledge of the electrical properties electron emission yield, conductivity and radiation induced conductivity) under electron, irradiation for each material of the spacecraft is needed for spacecraft plasma interaction software. The energy distribution of the emitted secondary and backscattered electrons was measured dynamically with the help of high-speed hemispherical electron energy analyzer. The evolution of the surface potential of the irradiated sample can be derived from the energy shift of the secondary electron pic. The method is applied to 25-µm Kapton.
{"title":"Low Energy Electron Irradiation Induced Charging of Dielectric Materials: Measurements and Analyses","authors":"M. Belhaj, S. Dadouch","doi":"10.1109/PPPS34859.2019.9009953","DOIUrl":"https://doi.org/10.1109/PPPS34859.2019.9009953","url":null,"abstract":"Charging of dielectric materials under electron irradiation is a commonly encountered problem in many space applications. Spacecraft charging due to solar and cosmic radiations may lead to critical discharge phenomenon. Indeed, under irradiation (especially electron irradiation), insulators as well as floating conductors may charge negatively or positively depending on the incident electron properties (energy, incidence angle, flux) and on the specific material properties (composition, surface roughness, contamination, temperature, etc.) The knowledge of the electrical properties electron emission yield, conductivity and radiation induced conductivity) under electron, irradiation for each material of the spacecraft is needed for spacecraft plasma interaction software. The energy distribution of the emitted secondary and backscattered electrons was measured dynamically with the help of high-speed hemispherical electron energy analyzer. The evolution of the surface potential of the irradiated sample can be derived from the energy shift of the secondary electron pic. The method is applied to 25-µm Kapton.","PeriodicalId":103240,"journal":{"name":"2019 IEEE Pulsed Power & Plasma Science (PPPS)","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116388594","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}
Pub Date : 2019-06-01DOI: 10.1109/PPPS34859.2019.9009983
Wei Zhang, Jie Guo
In this paper, the metal oxide is determined according to the characteristics of the very fast transient overvoltage (VFTO) waveform measured in the gas-insulated metal-enclosed switchgear (GIS) according to the standard regulations. The waveform parameters of the metal oxide varistor (MOV) test platform were designed to build pulse generators with 8µs, 100ns and 20ns wave-heads. Several typical MOVs for 110kV and 220kV system arresters were selected as samples. The impedance characteristics and response characteristics of MOV under the pulse of the above three different wave-head times are studied. The experimental results show that under the pulse of 8µs and 100ns with different amplitudes, the MOV voltage reaches the peak value and shows the inductance characteristics. The MOV under 20ns pulse shows different impedance characteristics. There is an impedance characteristic transition voltage U0, and at U0 voltage, the MOV shows resistivity. When the voltage peak on the MOV is less than U0, the current reaches the peak before the voltage, and the MOV mainly shows the capacitance characteristic. When the voltage peak on the MOV is greater than U0, the voltage reaches the peak before the current, and the MOV mainly shows the inductance characteristic. Under 8µs pulse, the time when the voltage and current on the MOV reach the peak value differ by 2.4µs; Under 100ns pulse, the time when the voltage and current on the MOV reach the peak value differ by 1µs; Under 20ns pulse, the time when the voltage and current on the MOV reach the peak value differ by less than 11ns. The shorter the wave-head time of the pulse, the smaller the difference between the time of the voltage and current peak value.
{"title":"Impedance Characteristics of Metal Oxide Varistor under Different Pulses","authors":"Wei Zhang, Jie Guo","doi":"10.1109/PPPS34859.2019.9009983","DOIUrl":"https://doi.org/10.1109/PPPS34859.2019.9009983","url":null,"abstract":"In this paper, the metal oxide is determined according to the characteristics of the very fast transient overvoltage (VFTO) waveform measured in the gas-insulated metal-enclosed switchgear (GIS) according to the standard regulations. The waveform parameters of the metal oxide varistor (MOV) test platform were designed to build pulse generators with 8µs, 100ns and 20ns wave-heads. Several typical MOVs for 110kV and 220kV system arresters were selected as samples. The impedance characteristics and response characteristics of MOV under the pulse of the above three different wave-head times are studied. The experimental results show that under the pulse of 8µs and 100ns with different amplitudes, the MOV voltage reaches the peak value and shows the inductance characteristics. The MOV under 20ns pulse shows different impedance characteristics. There is an impedance characteristic transition voltage U0, and at U0 voltage, the MOV shows resistivity. When the voltage peak on the MOV is less than U0, the current reaches the peak before the voltage, and the MOV mainly shows the capacitance characteristic. When the voltage peak on the MOV is greater than U0, the voltage reaches the peak before the current, and the MOV mainly shows the inductance characteristic. Under 8µs pulse, the time when the voltage and current on the MOV reach the peak value differ by 2.4µs; Under 100ns pulse, the time when the voltage and current on the MOV reach the peak value differ by 1µs; Under 20ns pulse, the time when the voltage and current on the MOV reach the peak value differ by less than 11ns. The shorter the wave-head time of the pulse, the smaller the difference between the time of the voltage and current peak value.","PeriodicalId":103240,"journal":{"name":"2019 IEEE Pulsed Power & Plasma Science (PPPS)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114291087","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}
Pub Date : 2019-06-01DOI: 10.1109/PPPS34859.2019.9009933
Varun, P. Shukla, A. Cross, K. Ronald, U. Pal
In this paper simulation analysis of the pseudospark discharge (PSD) has been carried out for the generation of high density and energetic electron beams from single to multi-gap PSD configurations using plasma simulation code OOPIC PRO. The generated e-beams are strongly influenced by the operating and geometrical parameters, such as, gas pressures (20–80 Pa), electrode apertures (2–10 mm), number of gaps (1–4), trigger energy (1–4 kV) and applied voltage (10–40kV). The generated e-beam currents decrease with the increase in electrode apertures while increase with increase in gas pressures. Detailed consideration is required for choosing suitable trigger energy to operate at higher gas pressures and lower cathode apertures in the multi-gap PSD arrangement. It has been observed that there is decrease in the breakdown voltage for increasing gas pressures and electrode apertures. The potential distribution in the PSD source has vital role for confinement of the plasma and generation of high density and energetic e-beams of different peak currents and sizes.
{"title":"Plasma Simulation and Modeling of Pseudospark Discharge for High Density and Energetic Electron Beam Generation","authors":"Varun, P. Shukla, A. Cross, K. Ronald, U. Pal","doi":"10.1109/PPPS34859.2019.9009933","DOIUrl":"https://doi.org/10.1109/PPPS34859.2019.9009933","url":null,"abstract":"In this paper simulation analysis of the pseudospark discharge (PSD) has been carried out for the generation of high density and energetic electron beams from single to multi-gap PSD configurations using plasma simulation code OOPIC PRO. The generated e-beams are strongly influenced by the operating and geometrical parameters, such as, gas pressures (20–80 Pa), electrode apertures (2–10 mm), number of gaps (1–4), trigger energy (1–4 kV) and applied voltage (10–40kV). The generated e-beam currents decrease with the increase in electrode apertures while increase with increase in gas pressures. Detailed consideration is required for choosing suitable trigger energy to operate at higher gas pressures and lower cathode apertures in the multi-gap PSD arrangement. It has been observed that there is decrease in the breakdown voltage for increasing gas pressures and electrode apertures. The potential distribution in the PSD source has vital role for confinement of the plasma and generation of high density and energetic e-beams of different peak currents and sizes.","PeriodicalId":103240,"journal":{"name":"2019 IEEE Pulsed Power & Plasma Science (PPPS)","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114399294","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}
Pub Date : 2019-06-01DOI: 10.1109/PPPS34859.2019.9009872
P. Ranjan, R. Sarathi, Ramkishore Kumar, P. Selvam, R. Jayaganthan, H. Suematsu
We propose the synthesis of MoC1-x nanoparticles (NPs) with Mo wire as starting material and to carryout explosion in the methane gas medium, which acts as carburizing medium, as well as a coolant, to bring down the local temperature rise to a value lower than the melting point of the material. To control the phase and morphology of NPs, two parameters are defined in wire explosion process (WEP): energy ratio, K (ratio of energy supplied to wire and sublimation energy of wire) and pressure, P of ambient gas. XRD, TEM, SEM and XPS were used to characterize the synthesized NPs. Pure Moc1-x was synthesized for K = 5.8 and P = 170 kPa. Carburization is more for high K/P. For low pressure case, one has to provide more K to get complete carburization. XPS confirms the formation of MoC without any oxidation of Mo vapour. Spherical NPs were obtained with least mean particle size of 20 nm. Particle size decreases with increase in K and/or decrease in P.
我们提出以钼丝为原料合成MoC1-x纳米粒子(NPs)，并在甲烷气体介质中进行爆炸，甲烷气体介质作为渗碳介质和冷却剂，使局部温升降低到低于材料的熔点。为了控制NPs的相和形态，在电线爆炸过程(WEP)中定义了两个参数:能量比K(提供给电线的能量与电线升华能的比值)和环境气体压力P。采用XRD、TEM、SEM和XPS对合成的纳米粒子进行了表征。在K = 5.8, P = 170 kPa的条件下合成了纯Moc1-x。高K/P渗碳效果更好。在低压情况下，必须提供更多的K才能完全渗碳。XPS证实MoC的形成没有任何Mo蒸气的氧化。得到球形NPs，平均粒径最小为20 nm。粒径随钾的增加和磷的减少而减小。
{"title":"Single-step Synthesis of Molybdenum Carbide Nanoparticles by Wire Explosion Process","authors":"P. Ranjan, R. Sarathi, Ramkishore Kumar, P. Selvam, R. Jayaganthan, H. Suematsu","doi":"10.1109/PPPS34859.2019.9009872","DOIUrl":"https://doi.org/10.1109/PPPS34859.2019.9009872","url":null,"abstract":"We propose the synthesis of MoC1-x nanoparticles (NPs) with Mo wire as starting material and to carryout explosion in the methane gas medium, which acts as carburizing medium, as well as a coolant, to bring down the local temperature rise to a value lower than the melting point of the material. To control the phase and morphology of NPs, two parameters are defined in wire explosion process (WEP): energy ratio, K (ratio of energy supplied to wire and sublimation energy of wire) and pressure, P of ambient gas. XRD, TEM, SEM and XPS were used to characterize the synthesized NPs. Pure Moc1-x was synthesized for K = 5.8 and P = 170 kPa. Carburization is more for high K/P. For low pressure case, one has to provide more K to get complete carburization. XPS confirms the formation of MoC without any oxidation of Mo vapour. Spherical NPs were obtained with least mean particle size of 20 nm. Particle size decreases with increase in K and/or decrease in P.","PeriodicalId":103240,"journal":{"name":"2019 IEEE Pulsed Power & Plasma Science (PPPS)","volume":"153 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116724390","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}
Pub Date : 2019-06-01DOI: 10.1109/PPPS34859.2019.9009987
I. Owens, C. Grabowski, N. Joseph, S. Coffey, B. Ulmen, D. Kirschner, K. Rainwater, K. Struve
The electric field strength between the cathode and anode (i.e., the voltage) of a pulsed power machine is one of the most important operating parameters of the device. However, to date, accurate and precise voltage measurements on these high energy pulsed power systems have proved difficult if not virtually impossible to perform. In many cases, the measurements to be performed take place in an environment cluttered with electromagnetic interference (EMI), radio frequency interference (RFI), and electron pollution, and there is the potential for electrical discharge (or arcing), there is limited physical access, or the measurement area is deemed unsuitable due to radiation safety concerns. We report on an electro-optical-based approach to measuring strong, narrow-pulse-width electric fields that requires no interfering metallic probes or components to disturb the field to be measured. Here we focus on device theory, operating parameters and a laboratory experiment.
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