D. Suszcynsky - Academia.edu (original) (raw)
Papers by D. Suszcynsky
Journal of Geophysical Research, 1999
1990 Plasma Science IEEE Conference Record - Abstracts, 1990
ABSTRACT Summary form only given. The response of an unmagnetized plasma to rapidly biased object... more ABSTRACT Summary form only given. The response of an unmagnetized plasma to rapidly biased objects is being studied in a multidipole plasma discharge device. The time evolution of plasma return currents to these objects, subsequent electron ringing at the plasma frequency, and related electrostatic wave phenomena have been investigated, and the results have been compared with theoretical predictions and one-dimensional particle-in-cell computer simulations. A high-speed dual-channel spectrometer which measures the energy-time spectra of electrons and ions collected by the objects has been designed and operated
Advances in Space Research, 1993
The charging dynamics of ice particles in plasmas (e.g. for planetary ring dynamics) is highly de... more The charging dynamics of ice particles in plasmas (e.g. for planetary ring dynamics) is highly dependent upon the secondary-electron yields of the ices. To this end, the secondary-electron yields of H 20, C02, NH3 (ammonia) and CH3OH (methanol) ices have been measured in a scanning electron microscope as a function of the electron-beam energy in the 2-30 keV energy range. Estimates are given for the maximum secondary-electron yield Yma~of each ice and the energy Emax at which this maximum yield occurs and the implications of these estimates are discussed in terms of solar system ices. Based on these results and a general literature review of Ymax values for nonconducting materials, it is suggested that a typical range to quote for the secondary-electron yield of ices should be about 1-10. This is much lower than the range of 1-30 that is presently quoted in the space physics community.
This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) pro... more This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). An all-sky video camera system was deployed in Eagle, Alaska at the foot of the magnetic field line that threads geosynchronous satellite 1989-046 as part of a campaign to study correlations of ground-based auroral activity with satellite-based plasma and energetic particle measurements. The overall intent of the project was to study magnetosphere-ionosphere coupling as it relates to the aurora, and, in particular, to look for signatures that may help to identify various auroral generator mechanism(s). During this study, our efforts were primarily directed towards identifying the generator mechanism(s) for pulsating aurora. Our data, though not conclusive, are found to support theories that propose a cyclotron resonance mechanism for the generation of auroral pulsations.
A six year record of optical observations of lightning-induced mesospheric transient luminous eve... more A six year record of optical observations of lightning-induced mesospheric transient luminous events (TLEs) is available from the Yucca Ridge Field Station (YRFS) near Ft. Collins, CO. Climatological analyses reveal sprites and elves occur in a variety of convective storm types, but principally mesoscale convective systems (MCSs) and squall lines. Severe supercell storms rarely produce TLEs, except during their dissipating
Journal of Geophysical Research, 1993
ABSTRACT The plasma sheet horns are the low-altitude extensions of the plasma sheet that lie pole... more ABSTRACT The plasma sheet horns are the low-altitude extensions of the plasma sheet that lie poleward of the plasmasphere and equatorward of the tail lobes. Within the horns, magnetic field lines of increasing geomagnetic latitudes map to increasing distances into the downtail plasma sheet. Plasma data from the fast plasma experiment on ISEE 2 have been analyzed for 11 outbound crossings of the horns in the premidnight sector of the magnetosphere at typical altitudes of 2-4 R(E). These crossings typically occurred on time scales of less than 1 hour, providing almost instantaneous snapshots of plasma gradients within the horns. Ion temperatures observed during these crossings generally decreased by a factor of four to eight as magnetic field lines of increasing geomagnetic latitude were traversed. If we make the reasonable assumption that the ion temperatures are constant along the field lines within the plasma sheet, then this result implies that the ion temperatures in the downtail plasma sheet also commonly decrease by this same factor over the radial range extending from the inner edge of the plasma sheet at the plasmapause boundary to the outer edge at a neutral line in the distant tail.
Journal of Geophysical Research, 1999
Journal of Atmospheric and Solar-Terrestrial Physics, 1998
PERGAMON Journal of Atmospheric and Solar-Terrestrial Physics 60 (1998) 787-799 Journal of ATMOSP... more PERGAMON Journal of Atmospheric and Solar-Terrestrial Physics 60 (1998) 787-799 Journal of ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS Photometric measurements in the SPRITES '95 & '96 campaigns of nitrogen second positive (399.8 nm) and ...
Geophysical Research Letters, 2000
Recent time-resolved multi-color photometric data obtained on one class of lightning-related tran... more Recent time-resolved multi-color photometric data obtained on one class of lightning-related transient upperatmospheric electromagnetic events called sprites have confirmed an impulsive ionization emission during the sprite initiation. Data have also been obtained on some sprites which do not exhibit observable tendrils and which exhibit ionization emission that, if present, is below our detection limit. This suggests that some sprite events exhibit strong ionization while others do not. These results indicate that conditions causing sprite optical emissions are highly variable.
Physics of Fluids, 1987
ABSTRACT The damping of electrostatic ion-cyclotron waves by ion-neutral collisions was studied i... more ABSTRACT The damping of electrostatic ion-cyclotron waves by ion-neutral collisions was studied in a single-ended Q machine. The amplitudes of K(+) and Cs(+) electrostatic ion-cyclotron waves were measured as a function of neutral pressure in helium, neon, argon, krypton, and xenon. For each ion/neutral atom combination, the electrostatic ion-cyclotron wave amplitude maximizes at a neutral pressure that scales monotonically with the m(+)/m(n) mass ratio. This result is interpreted by considering the dynamics of elastic collisions between the ions and the neutral atoms.
FORTE and GPS satellite studies have shown that satellite-based VHF lightning sensors are particu... more FORTE and GPS satellite studies have shown that satellite-based VHF lightning sensors are particularly sensitive to a ubiquitous and unique type of strong in-cloud RF lightning pulse that is sometimes accompanied by a Narrow Bipolar Event (NBE). The physical relationship between NBEs and their impulsive VHF counterparts is not clear. Presumably, the strong VHF pulses are associated with an initiating
Over the last several years, the remote sensing of very high frequency (VHF) lightning emissions ... more Over the last several years, the remote sensing of very high frequency (VHF) lightning emissions from both low-earth orbit and Global Positioning System (GPS) orbit has been demonstrated with the Fast On-Orbit Recording of Transient Events (FORTE) satellite and with an experimental VHF receiver aboard the SVN 54 GPS satellite. Analyses have shown that these systems are most sensitive to
Over the last few decades, there has been a growing interest to develop and deploy an automated a... more Over the last few decades, there has been a growing interest to develop and deploy an automated and continuously operating satellite-based global lightning mapper [e.g. Christian et al., 1989; Weber et al., 1998; Suszcynsky et al., 2000]. Lightning is a direct consequence of the electrification and breakdown processes that take place during the convective stages of thunderstorm development. Satellite-based lightning
Hurricane eyewall lightning is seldom observed during the development and quiescent periods of a ... more Hurricane eyewall lightning is seldom observed during the development and quiescent periods of a hurricane's lifetime. However, observational evidence collected during the 2004 and 2005 hurricane seasons suggests that abundant eyewall lightning is present during periods of rapid intensification. We provide a conceptual model of hurricane electrification during the rapid intensification phase, and analyze the current and historical Atlantic hurricane
Review of Scientific Instruments, 1996
By modeling the statistical evolution of an avalanche created by 20 keV protons impacting the inp... more By modeling the statistical evolution of an avalanche created by 20 keV protons impacting the input surface of a z-stack microchannel plate ͑MCP͒ detector, the mean secondary electron yield ␥ C of avalanche electrons propagating through a MCP channel is measured to equal 1.37 for 760 V per MCP in the z stack. This value agrees with other studies that used MCP gain measurements to infer ␥ C . The technique described here to measure ␥ C is independent of gain saturation effects and simplifying assumptions used in the segmented dynode model, both of which can introduce errors when inferring ␥ C through gain measurements.
Review of Scientific Instruments, 1996
We present data demonstrating the influence of an applied electric field {ital E} oriented normal... more We present data demonstrating the influence of an applied electric field {ital E} oriented normal to the input surface of a microchannel plate (MCP) detector on the critical operating parameters of the detector, including the quantum detection efficiency, the spatial resolution, and pulse height distribution. The MCP detector response is characterized using 20 keV protons as the primary radiation. An applied electric field {ital E}â«-4 V/mm, where a negative value of {ital E} corresponds to a nearby object that is biased positive relative to the input surface, results in a high spatial resolution and a quantum detection efficiency that is approximately equal to the open area ratio of the MCP. An electric field -1â«{ital E}â«5 V/mm results in low spatial resolution, in which up to 32% of the measured signal appears as a localized noise that extends several millimeters from the point of ion impact, and a maximum quantum detection efficiency of approximately 0.87. Furthermore, a separate peak in the pulse-height distribution arises from ions striking the web of the MCP detector and has a much lower pulse magnitude than that of ions striking channels. For {ital E}â³5 V/mm, the spatial resolution increases, and the quantum detection efficiency slightly decreases from its maximum value with increasing {ital E}. The characteristics of each of these electric field configurations are analyzed in the context of the yield and transport of secondary electrons created at the web of the MCP detector, and the results can be scaled to other ions and energies according to the secondary electron yield of ions striking the web. {copyright} {ital 1996 American Institute of Physics.}
ABSTRACT This is the final report of a two-year, Laboratory Directed Research and Development (LD... more ABSTRACT This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project sought to develop microchannel plate (MCP) technologies for enhancement of night vision device (NVD) capabilities. First, the authors addressed the need for segmented microchannel plates with independent gain control to minimize loss of low level light images in the presence of a bright light source (e.g., battlefield lasers, flares, and headlights). This would enable, for example, enhanced vision capabilities during night operations in a city environment and continuous capability of aviators to see the horizon, near-ground obstructions, and ground targets. Second, the authors addressed the need for curved microchannel plate technology to increase the field of view of NVDs while minimizing optical aberrations. This development would significantly enhance peripheral vision capabilities of aviators and result in easier adaptation of the human eye to NVDs. The authors have developed two technologies to overcome these problems, and they have initiated a collaborative effort with an industrial partner to develop a proof-of-principle prototype.
For the last two years, Los Alamos National Laboratory has sponsored an internal hurricane lightn... more For the last two years, Los Alamos National Laboratory has sponsored an internal hurricane lightning project with four main goals: (1) To develop and deploy a new dual VLF/VHF lightning mapping array in the Mississippi River Delta south of New Orleans. (2) To develop a new hurricane forecast capability with fully prognostic cloud electrification and lightning discharge physics, based on
Eos, Transactions American Geophysical Union, 2005
Journal of Geophysical Research, 1999
1990 Plasma Science IEEE Conference Record - Abstracts, 1990
ABSTRACT Summary form only given. The response of an unmagnetized plasma to rapidly biased object... more ABSTRACT Summary form only given. The response of an unmagnetized plasma to rapidly biased objects is being studied in a multidipole plasma discharge device. The time evolution of plasma return currents to these objects, subsequent electron ringing at the plasma frequency, and related electrostatic wave phenomena have been investigated, and the results have been compared with theoretical predictions and one-dimensional particle-in-cell computer simulations. A high-speed dual-channel spectrometer which measures the energy-time spectra of electrons and ions collected by the objects has been designed and operated
Advances in Space Research, 1993
The charging dynamics of ice particles in plasmas (e.g. for planetary ring dynamics) is highly de... more The charging dynamics of ice particles in plasmas (e.g. for planetary ring dynamics) is highly dependent upon the secondary-electron yields of the ices. To this end, the secondary-electron yields of H 20, C02, NH3 (ammonia) and CH3OH (methanol) ices have been measured in a scanning electron microscope as a function of the electron-beam energy in the 2-30 keV energy range. Estimates are given for the maximum secondary-electron yield Yma~of each ice and the energy Emax at which this maximum yield occurs and the implications of these estimates are discussed in terms of solar system ices. Based on these results and a general literature review of Ymax values for nonconducting materials, it is suggested that a typical range to quote for the secondary-electron yield of ices should be about 1-10. This is much lower than the range of 1-30 that is presently quoted in the space physics community.
This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) pro... more This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). An all-sky video camera system was deployed in Eagle, Alaska at the foot of the magnetic field line that threads geosynchronous satellite 1989-046 as part of a campaign to study correlations of ground-based auroral activity with satellite-based plasma and energetic particle measurements. The overall intent of the project was to study magnetosphere-ionosphere coupling as it relates to the aurora, and, in particular, to look for signatures that may help to identify various auroral generator mechanism(s). During this study, our efforts were primarily directed towards identifying the generator mechanism(s) for pulsating aurora. Our data, though not conclusive, are found to support theories that propose a cyclotron resonance mechanism for the generation of auroral pulsations.
A six year record of optical observations of lightning-induced mesospheric transient luminous eve... more A six year record of optical observations of lightning-induced mesospheric transient luminous events (TLEs) is available from the Yucca Ridge Field Station (YRFS) near Ft. Collins, CO. Climatological analyses reveal sprites and elves occur in a variety of convective storm types, but principally mesoscale convective systems (MCSs) and squall lines. Severe supercell storms rarely produce TLEs, except during their dissipating
Journal of Geophysical Research, 1993
ABSTRACT The plasma sheet horns are the low-altitude extensions of the plasma sheet that lie pole... more ABSTRACT The plasma sheet horns are the low-altitude extensions of the plasma sheet that lie poleward of the plasmasphere and equatorward of the tail lobes. Within the horns, magnetic field lines of increasing geomagnetic latitudes map to increasing distances into the downtail plasma sheet. Plasma data from the fast plasma experiment on ISEE 2 have been analyzed for 11 outbound crossings of the horns in the premidnight sector of the magnetosphere at typical altitudes of 2-4 R(E). These crossings typically occurred on time scales of less than 1 hour, providing almost instantaneous snapshots of plasma gradients within the horns. Ion temperatures observed during these crossings generally decreased by a factor of four to eight as magnetic field lines of increasing geomagnetic latitude were traversed. If we make the reasonable assumption that the ion temperatures are constant along the field lines within the plasma sheet, then this result implies that the ion temperatures in the downtail plasma sheet also commonly decrease by this same factor over the radial range extending from the inner edge of the plasma sheet at the plasmapause boundary to the outer edge at a neutral line in the distant tail.
Journal of Geophysical Research, 1999
Journal of Atmospheric and Solar-Terrestrial Physics, 1998
PERGAMON Journal of Atmospheric and Solar-Terrestrial Physics 60 (1998) 787-799 Journal of ATMOSP... more PERGAMON Journal of Atmospheric and Solar-Terrestrial Physics 60 (1998) 787-799 Journal of ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS Photometric measurements in the SPRITES '95 & '96 campaigns of nitrogen second positive (399.8 nm) and ...
Geophysical Research Letters, 2000
Recent time-resolved multi-color photometric data obtained on one class of lightning-related tran... more Recent time-resolved multi-color photometric data obtained on one class of lightning-related transient upperatmospheric electromagnetic events called sprites have confirmed an impulsive ionization emission during the sprite initiation. Data have also been obtained on some sprites which do not exhibit observable tendrils and which exhibit ionization emission that, if present, is below our detection limit. This suggests that some sprite events exhibit strong ionization while others do not. These results indicate that conditions causing sprite optical emissions are highly variable.
Physics of Fluids, 1987
ABSTRACT The damping of electrostatic ion-cyclotron waves by ion-neutral collisions was studied i... more ABSTRACT The damping of electrostatic ion-cyclotron waves by ion-neutral collisions was studied in a single-ended Q machine. The amplitudes of K(+) and Cs(+) electrostatic ion-cyclotron waves were measured as a function of neutral pressure in helium, neon, argon, krypton, and xenon. For each ion/neutral atom combination, the electrostatic ion-cyclotron wave amplitude maximizes at a neutral pressure that scales monotonically with the m(+)/m(n) mass ratio. This result is interpreted by considering the dynamics of elastic collisions between the ions and the neutral atoms.
FORTE and GPS satellite studies have shown that satellite-based VHF lightning sensors are particu... more FORTE and GPS satellite studies have shown that satellite-based VHF lightning sensors are particularly sensitive to a ubiquitous and unique type of strong in-cloud RF lightning pulse that is sometimes accompanied by a Narrow Bipolar Event (NBE). The physical relationship between NBEs and their impulsive VHF counterparts is not clear. Presumably, the strong VHF pulses are associated with an initiating
Over the last several years, the remote sensing of very high frequency (VHF) lightning emissions ... more Over the last several years, the remote sensing of very high frequency (VHF) lightning emissions from both low-earth orbit and Global Positioning System (GPS) orbit has been demonstrated with the Fast On-Orbit Recording of Transient Events (FORTE) satellite and with an experimental VHF receiver aboard the SVN 54 GPS satellite. Analyses have shown that these systems are most sensitive to
Over the last few decades, there has been a growing interest to develop and deploy an automated a... more Over the last few decades, there has been a growing interest to develop and deploy an automated and continuously operating satellite-based global lightning mapper [e.g. Christian et al., 1989; Weber et al., 1998; Suszcynsky et al., 2000]. Lightning is a direct consequence of the electrification and breakdown processes that take place during the convective stages of thunderstorm development. Satellite-based lightning
Hurricane eyewall lightning is seldom observed during the development and quiescent periods of a ... more Hurricane eyewall lightning is seldom observed during the development and quiescent periods of a hurricane's lifetime. However, observational evidence collected during the 2004 and 2005 hurricane seasons suggests that abundant eyewall lightning is present during periods of rapid intensification. We provide a conceptual model of hurricane electrification during the rapid intensification phase, and analyze the current and historical Atlantic hurricane
Review of Scientific Instruments, 1996
By modeling the statistical evolution of an avalanche created by 20 keV protons impacting the inp... more By modeling the statistical evolution of an avalanche created by 20 keV protons impacting the input surface of a z-stack microchannel plate ͑MCP͒ detector, the mean secondary electron yield ␥ C of avalanche electrons propagating through a MCP channel is measured to equal 1.37 for 760 V per MCP in the z stack. This value agrees with other studies that used MCP gain measurements to infer ␥ C . The technique described here to measure ␥ C is independent of gain saturation effects and simplifying assumptions used in the segmented dynode model, both of which can introduce errors when inferring ␥ C through gain measurements.
Review of Scientific Instruments, 1996
We present data demonstrating the influence of an applied electric field {ital E} oriented normal... more We present data demonstrating the influence of an applied electric field {ital E} oriented normal to the input surface of a microchannel plate (MCP) detector on the critical operating parameters of the detector, including the quantum detection efficiency, the spatial resolution, and pulse height distribution. The MCP detector response is characterized using 20 keV protons as the primary radiation. An applied electric field {ital E}â«-4 V/mm, where a negative value of {ital E} corresponds to a nearby object that is biased positive relative to the input surface, results in a high spatial resolution and a quantum detection efficiency that is approximately equal to the open area ratio of the MCP. An electric field -1â«{ital E}â«5 V/mm results in low spatial resolution, in which up to 32% of the measured signal appears as a localized noise that extends several millimeters from the point of ion impact, and a maximum quantum detection efficiency of approximately 0.87. Furthermore, a separate peak in the pulse-height distribution arises from ions striking the web of the MCP detector and has a much lower pulse magnitude than that of ions striking channels. For {ital E}â³5 V/mm, the spatial resolution increases, and the quantum detection efficiency slightly decreases from its maximum value with increasing {ital E}. The characteristics of each of these electric field configurations are analyzed in the context of the yield and transport of secondary electrons created at the web of the MCP detector, and the results can be scaled to other ions and energies according to the secondary electron yield of ions striking the web. {copyright} {ital 1996 American Institute of Physics.}
ABSTRACT This is the final report of a two-year, Laboratory Directed Research and Development (LD... more ABSTRACT This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project sought to develop microchannel plate (MCP) technologies for enhancement of night vision device (NVD) capabilities. First, the authors addressed the need for segmented microchannel plates with independent gain control to minimize loss of low level light images in the presence of a bright light source (e.g., battlefield lasers, flares, and headlights). This would enable, for example, enhanced vision capabilities during night operations in a city environment and continuous capability of aviators to see the horizon, near-ground obstructions, and ground targets. Second, the authors addressed the need for curved microchannel plate technology to increase the field of view of NVDs while minimizing optical aberrations. This development would significantly enhance peripheral vision capabilities of aviators and result in easier adaptation of the human eye to NVDs. The authors have developed two technologies to overcome these problems, and they have initiated a collaborative effort with an industrial partner to develop a proof-of-principle prototype.
For the last two years, Los Alamos National Laboratory has sponsored an internal hurricane lightn... more For the last two years, Los Alamos National Laboratory has sponsored an internal hurricane lightning project with four main goals: (1) To develop and deploy a new dual VLF/VHF lightning mapping array in the Mississippi River Delta south of New Orleans. (2) To develop a new hurricane forecast capability with fully prognostic cloud electrification and lightning discharge physics, based on
Eos, Transactions American Geophysical Union, 2005