Pub Date : 2013-06-16DOI: 10.1109/PLASMA.2013.6635091
Y. Tsui, Z. Chen, B. Holst, S. Kirkwood, V. Sametoglu, M. Reid, V. Recoules, A. Ng
AC conductivity has long been of interest in the study of electronic structure and transport properties of Warm Dense Matter. Using a chirped pulse probe technique, we have obtained single-shot measurements of the temporal evolution of AC conductivity during electron energy relaxation in non-equilibrium warm dense gold produced by femtosecond-laser heating with energy density up to 4.1MJ/kg (8×1010J/m3). The results uncover important changes that have been masked in earlier studies. Equally significant, they provide the first benchmark for testing an ab-initio model that is used to calculate electron heat capacity, electron-ion coupling and AC conductivity in a single, first principles framework. While measurements of the real part of AC conductivity corroborate our theoretical temperature-dependent electron heat capacity, they point to an electron-ion coupling factor of ~2.2×1016W/m3 K, substantially below that predicted by theory. In addition, measurements of the imaginary part of AC conductivity reveal the need to improve theoretical treatment of intraband contribution at very low photon energy.
{"title":"Evolution of AC conductivity in non-equilibrium warm dense gold","authors":"Y. Tsui, Z. Chen, B. Holst, S. Kirkwood, V. Sametoglu, M. Reid, V. Recoules, A. Ng","doi":"10.1109/PLASMA.2013.6635091","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6635091","url":null,"abstract":"AC conductivity has long been of interest in the study of electronic structure and transport properties of Warm Dense Matter. Using a chirped pulse probe technique, we have obtained single-shot measurements of the temporal evolution of AC conductivity during electron energy relaxation in non-equilibrium warm dense gold produced by femtosecond-laser heating with energy density up to 4.1MJ/kg (8×1010J/m3). The results uncover important changes that have been masked in earlier studies. Equally significant, they provide the first benchmark for testing an ab-initio model that is used to calculate electron heat capacity, electron-ion coupling and AC conductivity in a single, first principles framework. While measurements of the real part of AC conductivity corroborate our theoretical temperature-dependent electron heat capacity, they point to an electron-ion coupling factor of ~2.2×1016W/m3 K, substantially below that predicted by theory. In addition, measurements of the imaginary part of AC conductivity reveal the need to improve theoretical treatment of intraband contribution at very low photon energy.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77671858","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 : 2013-06-16DOI: 10.1109/PLASMA.2013.6634985
Wen-Jian Kuang, Qing Li, Lanlan Yang, Y. Tu, Xiong Zhang, H. Tolner, Baoping Wang
Summary form only given. A type of ultra-thin shadow-mask plasma microdischarge device is being developed for the high-quality display and UVB phototherapy. Thanks to the 150 μm shadow-mask and the 70 μm borosilicate glass with a dielectric constant of 6.7, a sealed panel can be fabricated as thin as 300 μm while the thickness of the device with electrode bandings can be made less than 1 mm1. The shadow-mask is a special metal mesh which is used to form the discharge cells and embed phosphors. The upper part of the discharge cell has a diamond design and the lower part is slot shaped and the gas channels are made in the back side. The shadow-mask replaces the rib wall while the thin glass sheets are used instead of the conventional dielectric layers. So the structure is simplified as a sandwich which includes the front and rear thin glass sheets, the shadow-mask, MgO layers and the exterior electrodes. Moreover, a special vacuum in-line sealing system, which consists of a vacuum chamber, temperature control system and gas filling system, is applied to the fabrication. The panels can be sealed directly in the system without pumping tubes. As an alternative promising application of the narrow-band (NB) UVB source, which can be used for treating skin diseases such as psoriasis2, dermatitis and alopecia areata, the device has the advantages of flexible, addressable and excellent air-tightness. In order to radiate the NB-UVB from the devices, the 312 nm emission phosphors are deposited on the front side of shadow-mask. The UV-transmission of 312 nm can reach about 80% from the phosphor to the outside of a thin alkali-free glass. The experimental results demonstrate that the high content of Xe can be used in the devices and improve both of the emission and efficiency. Furthermore, double-sided radiation can be realized due to the mesh-structure shadow mask.
{"title":"Ultra-thin shadow-mask plasma display panel and NB-UVB source","authors":"Wen-Jian Kuang, Qing Li, Lanlan Yang, Y. Tu, Xiong Zhang, H. Tolner, Baoping Wang","doi":"10.1109/PLASMA.2013.6634985","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6634985","url":null,"abstract":"Summary form only given. A type of ultra-thin shadow-mask plasma microdischarge device is being developed for the high-quality display and UVB phototherapy. Thanks to the 150 μm shadow-mask and the 70 μm borosilicate glass with a dielectric constant of 6.7, a sealed panel can be fabricated as thin as 300 μm while the thickness of the device with electrode bandings can be made less than 1 mm1. The shadow-mask is a special metal mesh which is used to form the discharge cells and embed phosphors. The upper part of the discharge cell has a diamond design and the lower part is slot shaped and the gas channels are made in the back side. The shadow-mask replaces the rib wall while the thin glass sheets are used instead of the conventional dielectric layers. So the structure is simplified as a sandwich which includes the front and rear thin glass sheets, the shadow-mask, MgO layers and the exterior electrodes. Moreover, a special vacuum in-line sealing system, which consists of a vacuum chamber, temperature control system and gas filling system, is applied to the fabrication. The panels can be sealed directly in the system without pumping tubes. As an alternative promising application of the narrow-band (NB) UVB source, which can be used for treating skin diseases such as psoriasis2, dermatitis and alopecia areata, the device has the advantages of flexible, addressable and excellent air-tightness. In order to radiate the NB-UVB from the devices, the 312 nm emission phosphors are deposited on the front side of shadow-mask. The UV-transmission of 312 nm can reach about 80% from the phosphor to the outside of a thin alkali-free glass. The experimental results demonstrate that the high content of Xe can be used in the devices and improve both of the emission and efficiency. Furthermore, double-sided radiation can be realized due to the mesh-structure shadow mask.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80532605","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 : 2013-06-16DOI: 10.1109/PLASMA.2013.6633422
F. Santamaria, F. Roman
Summary form only given. A coaxial pulse generator was designed and constructed for an experimental study on a sub-millimeter spark-gap, where the characteristic impedance of the Pulse Forming Line (PFL) and the Transmission Line (TL) is Zc = 100Ω the spark-gap is located into a pressurized chamber between PFL and TL, and the transmission line generator ends at a 100Ω resistance (LOAD).resistance (LOAD). D-dot sensors, used to register the waveforms in both the PFL and TL, are not located exactly on the spark-gap; instead, they are laid 40 mm from the pressurized chamber along both the PFL and TL. To determine the effect of sensor position on voltage measurements, simulations using the EMTP-ATP program were carried out. The PFL voltage (V1) and TL voltage (V2) recorded in different places along the lines are analyzed by using distributed parameter models of the corresponding coaxial transmission lines and also including the electric-arc nonlinear model in the spark-gap switch. Additionally, the distributed parameter circuit models representing the effect of the dielectric materials were included. A MODEL of the spark-gap channel resistance was included. In the MODEL, both the resistive phase and the inductive phase of the gas discharge channel proposedby Martin1 were implemented. The difference between the signal recorded just after the spark-gap (V2) and the one recorded some tens of millimeters forward (V2') is the time delay due to the displacement of the measurement point. Additionally, when comparing the voltage signal recorded just before the spark-gap (V1) with the signal recorded some tens of millimeters backward (V1'), two differences can be observed. The former is the delay in the onset of the two signals. The second difference is a variation in the waveform of the signals. A hypothesis was formulated claiming that this is because the sensor does not record all the charge moving along the transmission line. To confirm this hypothesis, both the charge stored up to the D-dot sensor location and also the charge stored up until the spark-gap were calculated on the basis of EMTP-ATP simulations. The difference between these charges (21.63 nC) was compared with the charge stored in the segment of the transmission line (21.99 nC). The results of these calculations show a difference of 1.6 %, thus the hypothesis was validated.
{"title":"PPPS-2013: Electric field sensors effect on pulsed power measurements","authors":"F. Santamaria, F. Roman","doi":"10.1109/PLASMA.2013.6633422","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6633422","url":null,"abstract":"Summary form only given. A coaxial pulse generator was designed and constructed for an experimental study on a sub-millimeter spark-gap, where the characteristic impedance of the Pulse Forming Line (PFL) and the Transmission Line (TL) is Zc = 100Ω the spark-gap is located into a pressurized chamber between PFL and TL, and the transmission line generator ends at a 100Ω resistance (LOAD).resistance (LOAD). D-dot sensors, used to register the waveforms in both the PFL and TL, are not located exactly on the spark-gap; instead, they are laid 40 mm from the pressurized chamber along both the PFL and TL. To determine the effect of sensor position on voltage measurements, simulations using the EMTP-ATP program were carried out. The PFL voltage (V1) and TL voltage (V2) recorded in different places along the lines are analyzed by using distributed parameter models of the corresponding coaxial transmission lines and also including the electric-arc nonlinear model in the spark-gap switch. Additionally, the distributed parameter circuit models representing the effect of the dielectric materials were included. A MODEL of the spark-gap channel resistance was included. In the MODEL, both the resistive phase and the inductive phase of the gas discharge channel proposedby Martin1 were implemented. The difference between the signal recorded just after the spark-gap (V2) and the one recorded some tens of millimeters forward (V2') is the time delay due to the displacement of the measurement point. Additionally, when comparing the voltage signal recorded just before the spark-gap (V1) with the signal recorded some tens of millimeters backward (V1'), two differences can be observed. The former is the delay in the onset of the two signals. The second difference is a variation in the waveform of the signals. A hypothesis was formulated claiming that this is because the sensor does not record all the charge moving along the transmission line. To confirm this hypothesis, both the charge stored up to the D-dot sensor location and also the charge stored up until the spark-gap were calculated on the basis of EMTP-ATP simulations. The difference between these charges (21.63 nC) was compared with the charge stored in the segment of the transmission line (21.99 nC). The results of these calculations show a difference of 1.6 %, thus the hypothesis was validated.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79388465","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 : 2013-06-16DOI: 10.1109/PLASMA.2013.6633213
S. Fuelling, B. Bauer, I. Lindemuth, R. Siemon, K. Yates
Summary form only given. In MTF liner compression experiments, MG magnetic fields heat up the inner liner surface during compression, possibly leading to gas or plasma formation and mixing of wall material with the fuel. To investigate the conditions leading to plasma formation from an inner metal liner surface, experiments have been performed on the 1-MA Zebra generator, by passing a fast-rising (1.1×1013 A/s rise rate) current through `barbell'-shaped aluminum (Al 6061) and copper (Cu 101) rods with diameters between 0.5 mm and 2 mm. The barbell shape avoids direct line-of-sight between arcs at contacts and the heated surface under investigation. Plasma formation is observed when the surface magnetic field approaches 2.2 MG for Al.1, 2, 3 The experiment also fulfills a need for detailed experimental data to benchmark radiation-MHD and plasma spectroscopy modeling. The metal plasma is well characterized by UV (266 nm) and visible (532 nm) 2-frame laser shadowgraphy, multi-frame optical imaging, filtered visible4 and EUV photometric measurements, and timeresolved visible and EUV spectroscopy. The magnetic field threshold for plasma formation, the expansion speed, the plasma temperature, and the emissions in visible and EUV bands have been compared with the results of a variety of numerical simulations, both Lagrangian and Eulerian, using several different sets of EOS, resistivity, and opacity tables.5,6 For the first time, a spectroscopic quality radiation transport line-of-sight integration for this Al plasma has been performed. Radiation-MHD modeling results from the MHRDR5 simulation is used as input for PrismSPECT spectral modeling. The line-of-sight integration takes into account the emission, absorption, and transmission of each plasma layer and finally is convoluted with the resolution of the EUV spectrometer. The resultant simulated spectrum compares well with the experimental EUV spectra.
只提供摘要形式。在MTF衬垫压缩实验中，MG磁场在压缩过程中加热内胆表面，可能导致气体或等离子体的形成以及壁材与燃料的混合。为了研究导致等离子体从内部金属衬垫表面形成的条件，在1 ma Zebra发电机上进行了实验，通过将快速上升(1.1×1013 a /s上升速率)的电流通过直径在0.5 mm到2mm之间的“杠铃”形铝(Al 6061)和铜(Cu 101)棒。杠铃形状避免了弧之间的直接视线在接触和受热表面的调查。当表面磁场接近2.2 MG时，观察到等离子体的形成。1,2,3实验还满足了对辐射mhd和等离子体光谱建模基准的详细实验数据的需求。金属等离子体通过紫外(266 nm)和可见光(532 nm) 2帧激光阴影成像、多帧光学成像、滤波可见光和EUV光度测量以及时间分辨可见光和EUV光谱进行了很好的表征。等离子体形成的磁场阈值，膨胀速度，等离子体温度，以及可见光和EUV波段的发射与各种数值模拟的结果进行了比较，包括拉格朗日和欧拉，使用了几组不同的EOS，电阻率和不透明度表。5,6首次对该铝等离子体进行了光谱质量辐射输运视距积分。MHRDR5模拟的辐射- mhd建模结果被用作PrismSPECT光谱建模的输入。视距积分考虑了每一等离子体层的发射、吸收和透射，最后与EUV光谱仪的分辨率有关。所得的模拟光谱与实验的EUV光谱具有较好的一致性。
{"title":"Multiband time-resolved spectra of metal surface plasmas: Comparison of experiment with plasma spectroscopic modeling","authors":"S. Fuelling, B. Bauer, I. Lindemuth, R. Siemon, K. Yates","doi":"10.1109/PLASMA.2013.6633213","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6633213","url":null,"abstract":"Summary form only given. In MTF liner compression experiments, MG magnetic fields heat up the inner liner surface during compression, possibly leading to gas or plasma formation and mixing of wall material with the fuel. To investigate the conditions leading to plasma formation from an inner metal liner surface, experiments have been performed on the 1-MA Zebra generator, by passing a fast-rising (1.1×1013 A/s rise rate) current through `barbell'-shaped aluminum (Al 6061) and copper (Cu 101) rods with diameters between 0.5 mm and 2 mm. The barbell shape avoids direct line-of-sight between arcs at contacts and the heated surface under investigation. Plasma formation is observed when the surface magnetic field approaches 2.2 MG for Al.1, 2, 3 The experiment also fulfills a need for detailed experimental data to benchmark radiation-MHD and plasma spectroscopy modeling. The metal plasma is well characterized by UV (266 nm) and visible (532 nm) 2-frame laser shadowgraphy, multi-frame optical imaging, filtered visible4 and EUV photometric measurements, and timeresolved visible and EUV spectroscopy. The magnetic field threshold for plasma formation, the expansion speed, the plasma temperature, and the emissions in visible and EUV bands have been compared with the results of a variety of numerical simulations, both Lagrangian and Eulerian, using several different sets of EOS, resistivity, and opacity tables.5,6 For the first time, a spectroscopic quality radiation transport line-of-sight integration for this Al plasma has been performed. Radiation-MHD modeling results from the MHRDR5 simulation is used as input for PrismSPECT spectral modeling. The line-of-sight integration takes into account the emission, absorption, and transmission of each plasma layer and finally is convoluted with the resolution of the EUV spectrometer. The resultant simulated spectrum compares well with the experimental EUV spectra.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81906403","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 : 2013-06-16DOI: 10.1109/PLASMA.2013.6634861
J. Holma, M. Barnes
The CLIC study is exploring the scheme for an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC pre-damping rings and damping rings (DRs) will produce, through synchrotron radiation, ultra-low emittance beam with high bunch charge. To avoid beam emittance increase, the damping ring kicker systems must provide extremely flat, high-voltage, pulses. The specifications for the extraction kickers of the DRs are particularly demanding: the flattops of the pulses must be ±12.5 kV with a combined ripple and droop of not more than ±0.02 % (±2.5 V). An inductive adder is a very promising approach to meeting the specifications.
{"title":"Initial measurements on a prototype inductive adder with ultra-flat output pulse for the CLIC kicker systems","authors":"J. Holma, M. Barnes","doi":"10.1109/PLASMA.2013.6634861","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6634861","url":null,"abstract":"The CLIC study is exploring the scheme for an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC pre-damping rings and damping rings (DRs) will produce, through synchrotron radiation, ultra-low emittance beam with high bunch charge. To avoid beam emittance increase, the damping ring kicker systems must provide extremely flat, high-voltage, pulses. The specifications for the extraction kickers of the DRs are particularly demanding: the flattops of the pulses must be ±12.5 kV with a combined ripple and droop of not more than ±0.02 % (±2.5 V). An inductive adder is a very promising approach to meeting the specifications.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84569339","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 : 2013-06-16DOI: 10.1109/PLASMA.2013.6635214
Yingda Cheng, A. Christlieb, Xinghui Zhong
We develop energy conserving schemes for Vlasov-Ampere and Vlasov-Maxwell systems. The proposed methods preserve the total energy of the system on the fully discrete level, and they have a systematic framework to incorporate explicit and implicit temporal discretizations. The discontinuous Galerkin methods with suitable numerical fluxes are used to guarantee such properties, and they could be designed with potential implementations on unstructured meshes. Benchmark numerical test results will be provided.
{"title":"PPPS-2013: Energy conserving numerical schemes for Vlasov-Ampere and Vlasov-Maxwell systems","authors":"Yingda Cheng, A. Christlieb, Xinghui Zhong","doi":"10.1109/PLASMA.2013.6635214","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6635214","url":null,"abstract":"We develop energy conserving schemes for Vlasov-Ampere and Vlasov-Maxwell systems. The proposed methods preserve the total energy of the system on the fully discrete level, and they have a systematic framework to incorporate explicit and implicit temporal discretizations. The discontinuous Galerkin methods with suitable numerical fluxes are used to guarantee such properties, and they could be designed with potential implementations on unstructured meshes. Benchmark numerical test results will be provided.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85152063","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 : 2013-06-16DOI: 10.1109/PLASMA.2013.6633293
W. Meeks, J. Rovey
Summary form only given. Pulsed inductive plasma devices such as the common theta-pinch have become a standard high energy plasma source in research and industry. Recent pulsed inductive plasmas currently being investigated by the fusion and space propulsion communities utilize deuterium and xenon, respectively, and have provided promising new results. However, little has been done to better understand the energy conversion processes during early plasma formation times (i.e., during the initial inductive coupling). The broad efforts of this research are to elucidate the electric-to-particle energy conversion processes during initial plasma formation over time scales of 10-8 to 10-6 seconds. In this work an analysis of spectral emission data is performed on a theta pinch test article intended for use in field reversed configuration (FRC) studies. Testing is performed on a pulsed xenon plasma at energies of around 80 joules, neutral back-fill pressures of 10-2 Torr, and an RLC discharge frequency of 500 kHz. Efforts are paralleled by magnetic field studies (B-dot probes, flux loops) of the same experiment. Using a collisional-radiative model previously developed for analysis on xenon Hall effect thrusters, line emission intensity ratios are used to approximate electron temperatures independent of plasma density. A Princeton Instruments SP2300i spectrometer with PI-MAX 1024×1024 pixel iCCD camera is used with gate times of 10-9 to 10-8 seconds and variable delay to allow for time-resolved spectral data.
{"title":"PPPS-2013: Optical emission spectroscopy of initial plasma formation in a heavy gas theta pinch coil","authors":"W. Meeks, J. Rovey","doi":"10.1109/PLASMA.2013.6633293","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6633293","url":null,"abstract":"Summary form only given. Pulsed inductive plasma devices such as the common theta-pinch have become a standard high energy plasma source in research and industry. Recent pulsed inductive plasmas currently being investigated by the fusion and space propulsion communities utilize deuterium and xenon, respectively, and have provided promising new results. However, little has been done to better understand the energy conversion processes during early plasma formation times (i.e., during the initial inductive coupling). The broad efforts of this research are to elucidate the electric-to-particle energy conversion processes during initial plasma formation over time scales of 10-8 to 10-6 seconds. In this work an analysis of spectral emission data is performed on a theta pinch test article intended for use in field reversed configuration (FRC) studies. Testing is performed on a pulsed xenon plasma at energies of around 80 joules, neutral back-fill pressures of 10-2 Torr, and an RLC discharge frequency of 500 kHz. Efforts are paralleled by magnetic field studies (B-dot probes, flux loops) of the same experiment. Using a collisional-radiative model previously developed for analysis on xenon Hall effect thrusters, line emission intensity ratios are used to approximate electron temperatures independent of plasma density. A Princeton Instruments SP2300i spectrometer with PI-MAX 1024×1024 pixel iCCD camera is used with gate times of 10-9 to 10-8 seconds and variable delay to allow for time-resolved spectral data.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85197804","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 : 2013-06-16DOI: 10.1109/PLASMA.2013.6633308
N. Niasse, J. Chittenden
Summary form only given. We introduce Spooky, a fast multi-material non-LTE solver developed for large scale three-dimensional HEDP simulations. This highly optimized DCA code is sufficiently streamlined to run in parallel with the resistive Eulerian MHD code Gorgon1 in order to predict the thermodynamic and radiative properties of synthetic plasmas and generate filtered synthetic diagnostics outputs. An offline version of the model, including plasma motion Doppler, Stark, self absorption and lifetime broadening makes use of an original data structure to provide a more detailed post-processing treatment of spectral features. Results from simulations of shock interaction experiments2 performed with the MAGPIE generator are used to benchmark the code and non-LTE plasma effects are discussed. The capabilities of the model are illustrated with inline simulations of cylindrical wire array Z-pinch experiments carried out on the Z facility at Sandia National Laboratories and SPHINX facility at CEA. The high level of spectral details provided by the offline version of the code allows us to study the time-dependant evolution of spectral line broadening and the effect of plasma motion on the apparent ion temperature for the entire simulation volume.
{"title":"A multi-material NLTE code for HEDP simulations","authors":"N. Niasse, J. Chittenden","doi":"10.1109/PLASMA.2013.6633308","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6633308","url":null,"abstract":"Summary form only given. We introduce Spooky, a fast multi-material non-LTE solver developed for large scale three-dimensional HEDP simulations. This highly optimized DCA code is sufficiently streamlined to run in parallel with the resistive Eulerian MHD code Gorgon1 in order to predict the thermodynamic and radiative properties of synthetic plasmas and generate filtered synthetic diagnostics outputs. An offline version of the model, including plasma motion Doppler, Stark, self absorption and lifetime broadening makes use of an original data structure to provide a more detailed post-processing treatment of spectral features. Results from simulations of shock interaction experiments2 performed with the MAGPIE generator are used to benchmark the code and non-LTE plasma effects are discussed. The capabilities of the model are illustrated with inline simulations of cylindrical wire array Z-pinch experiments carried out on the Z facility at Sandia National Laboratories and SPHINX facility at CEA. The high level of spectral details provided by the offline version of the code allows us to study the time-dependant evolution of spectral line broadening and the effect of plasma motion on the apparent ion temperature for the entire simulation volume.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76597413","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 : 2013-06-16DOI: 10.1109/PLASMA.2013.6635082
Brandon Byrns, A. Lindsay, D. Knappe, S. Shannon
Plasma assisted water treatment systems present a compelling pathway for modification of water chemistry with reduced dependence on chemicals. Plasma production of oxidizing and reducing agents for chemical abatement, contaminant removal, and production of aqueous chemical agents without chemical feedstock present a potential transformative technology in the area of water treatment.An atmospheric plasma source operating at 162MHz1 is used to form reactive species that are incident on a downstream water source. While studying a variety of water treatment applications, several key challenges for practical implementation of this technology have been identified including improved pathways for water/plasma interaction and optimized chemistry for specific water treatment applications. Design of an improved device with increased efficiency in both airflow and water exposure will be presented. The interaction between the primary plasma discharge and water source, with emphasis on chemical composition and potential pathways for chemistry control are highlighted. Of specific interest is production and characterization of hydroxyl radicals through plasma water interaction. Experiments that characterize plasma conditions (specifically chemistry) andchanges to water chemistry will be presented. Potential applications of interest in the area of water treatment including treatment of perfluorinated compounds, atrazine, and dioxane in water supplies will be presented.
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Pub Date : 2013-06-16DOI: 10.1109/PLASMA.2013.6633168
T. Mehlhorn
Summary form only given. The NRL Plasma Physics Division was established in 1966 to create x-ray simulators for testing nuclear weapons effects (NWE) on materials and components of military hardware, to study the physics and effects of High Altitude Nuclear Explosions (HANE), and to perform nuclear fusion research. These missions are pursued today, utilizing decades of advances in pulsed power, intense beams, and high-power lasers; in the late 1960's, pulsed power physics was an emerging tool. A similar story existed at AWE where pulsed power was used for radiography. Sandia, Los Alamos, and Livermore all expanded their R&D into, and use of, pulsed power for a diverse set of missions including radiography, dynamic materials, nuclear weapons effects testing, and fusion. These early days had rudimentary computational models, were largely single module machines, and had a limited ability to synchronize and pulse shape. The Cold War, catalyzed by the 1983 Strategic Defense Initiative (“Star Wars”), saw a rapid growth of pulsed power technology in pursuit of directed energy weapons and x-ray lasers driven by intense charged particle beams or lasers. ICF programs also grew in impact and importance. The cessation of nuclear testing in 1992 created an increased need for “above ground testing” (AGT). This included e.panded needs for radiography, nuclear weapons effects simulators, and ICF facilities for studying HED physics and achieving thermonuclear burn in the laboratory. The premier systems of today's stockpile stewardship program (NIF, Z, Omega, and DAHRT) are powerful and energetic with sophisticated synchronization and pulse shaping capabilities. However, they are large, costly, and single-shot. The 2011 Naval Directed Energy Steering Group Charter and the 2012 Naval S&T Strategic Plan can give us glimpses of the future, at least for the DoD, with greater emphasis on hypervelocity railguns, directed energy, detection and neutralization of WMD, autonomous systems, and the ability to retain access in contested environments, especially space. They also call for technologies that decrease the dependence on fossil fuels and shorten logistic chains. The future increasingly calls for creating compact, efficient, repetitive sources of prime pulsed power, compact accelerators, railguns, directed energy systems, and related capabilities. These themes also run through the 2011 DOE Report “Accelerators for America's Future”. Together, we'll look into our crystal balls at the challenges and opportunities for future plasma physics and pulsed power research.
{"title":"PPPS-2013: Abstract submission national security research in plasma physics and pulsed power: Past, present, and future","authors":"T. Mehlhorn","doi":"10.1109/PLASMA.2013.6633168","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6633168","url":null,"abstract":"Summary form only given. The NRL Plasma Physics Division was established in 1966 to create x-ray simulators for testing nuclear weapons effects (NWE) on materials and components of military hardware, to study the physics and effects of High Altitude Nuclear Explosions (HANE), and to perform nuclear fusion research. These missions are pursued today, utilizing decades of advances in pulsed power, intense beams, and high-power lasers; in the late 1960's, pulsed power physics was an emerging tool. A similar story existed at AWE where pulsed power was used for radiography. Sandia, Los Alamos, and Livermore all expanded their R&D into, and use of, pulsed power for a diverse set of missions including radiography, dynamic materials, nuclear weapons effects testing, and fusion. These early days had rudimentary computational models, were largely single module machines, and had a limited ability to synchronize and pulse shape. The Cold War, catalyzed by the 1983 Strategic Defense Initiative (“Star Wars”), saw a rapid growth of pulsed power technology in pursuit of directed energy weapons and x-ray lasers driven by intense charged particle beams or lasers. ICF programs also grew in impact and importance. The cessation of nuclear testing in 1992 created an increased need for “above ground testing” (AGT). This included e.panded needs for radiography, nuclear weapons effects simulators, and ICF facilities for studying HED physics and achieving thermonuclear burn in the laboratory. The premier systems of today's stockpile stewardship program (NIF, Z, Omega, and DAHRT) are powerful and energetic with sophisticated synchronization and pulse shaping capabilities. However, they are large, costly, and single-shot. The 2011 Naval Directed Energy Steering Group Charter and the 2012 Naval S&T Strategic Plan can give us glimpses of the future, at least for the DoD, with greater emphasis on hypervelocity railguns, directed energy, detection and neutralization of WMD, autonomous systems, and the ability to retain access in contested environments, especially space. They also call for technologies that decrease the dependence on fossil fuels and shorten logistic chains. The future increasingly calls for creating compact, efficient, repetitive sources of prime pulsed power, compact accelerators, railguns, directed energy systems, and related capabilities. These themes also run through the 2011 DOE Report “Accelerators for America's Future”. Together, we'll look into our crystal balls at the challenges and opportunities for future plasma physics and pulsed power research.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81984419","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}
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