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High current magnetized plasma discharges and electron beams for capture and cooling of charged leptons and hadrons

Description: Nowadays most magnetic lenses used to capture and to focus pions and muons utilize azimuthal magnetic fields generated by large axial currents, like horns or lithium rods (or even a Z-pinch at GSI). Capture and focusing angle is proportional to the product of the current and length of the lens. State-of-the-art for these lenses is no more than 750 kA and 70 cm. A meter long, multi-MA, magnetized axial discharges were generated by the early days of fusion. Lenses based of such devices can increase the capture angle of pions, e.g., by more than a factor of 2. Electron beam cooling is presently achieved in storage rings by having charged particles interact with a co-moving electron beam. In these devices, typical parameters are electron beam currents of about 1 A, an interaction length of about 1 meter, and interaction time of about 30 msec. Multi-MA electron beams can be used for single-pass final stage cooling in a number of machines. Calculations for some applications, as well as other advantages indicate that these schemes deserve further more serious consideration.
Date: July 1, 1997
Creator: Hershcovitch, A.
Partner: UNT Libraries Government Documents Department

Fast resistive bolometry

Description: Resistive bolometry is an accurate, robust, spectrally broadband technique for measuring absolute x-ray fluence and flux. Bolometry is an independent technique for x-ray measurements that is based on a different set of physical properties than other diagnostics such as x-ray diodes, photoconducting detectors, and P-I-N diodes. Bolometers use the temperature-driven change in element resistivity to determine the total deposited energy. The calibration of such a device is based on fundamental material properties and its physical dimensions. The authors describe the use of nickel and gold bolometers to measure x rays generated by high power Z pinches on Sandia`s Saturn and Z accelerators. The Sandia bolometer design described herein has a pulse response of {approximately}1 ns. They describe in detail the fabrication, fielding, and data analysis issues leading to highly accurate x-ray measurements. The fundamental accuracy of resistive bolometry will be discussed.
Date: June 1, 1998
Creator: Spielman, R.B.; Deeney, C.; Fehl, D.L.; Hanson, D.L.; Keltner, N.R.; McGurn, J.S. et al.
Partner: UNT Libraries Government Documents Department

Wire array z-pinch insights for high x-ray power generation

Description: The discovery that the use of very large numbers of wires enables high x-ray power to be generated from wire-array z-pinches represents a breakthrough in load design for large pulsed power generators, and has permitted high temperatures to be generated in radiation cavities on Saturn and Z. In this paper, changes in x-ray emission characteristics as a function of wire number, array mass, and load radius, for 20-mm-long aluminum arrays on Saturn that led to these breakthrough hohlraum results, are discussed and compared with a few related emission characteristics of high-wire-number aluminum and tungsten arrays on Z. X-ray measurement comparisons with analytic models and 2-D radiation-magnetohydrodynamic (RMHC) code simulations in the x-y and r-z planes provide confidence in the ability of the models and codes to predict future x-ray performance with very-large-number wire arrays.
Date: December 31, 1997
Creator: Sanford, T.W.L.; Mock, R.C. & Marder, B.M.
Partner: UNT Libraries Government Documents Department

Pinch me - I'm fusing! Fusion Power - what is it? What is a z pinch? And why are z-pinches a promising fusion power technology?

Description: The process of combining nuclei (the protons and neutrons inside an atomic nucleus) together with a release of kinetic energy is called fusion. This process powers the Sun, it contributes to the world stockpile of weapons of mass destruction and may one day generate safe, clean electrical power. Understanding the intricacies of fusion power, promised for 50 years, is sometimes difficult because there are a number of ways of doing it. There is hot fusion, cold fusion and con-fusion. Hot fusion is what powers suns through the conversion of mass energy to kinetic energy. Cold fusion generates con-fusion and nobody really knows what it is. Even so, no one is generating electrical power for you and me with either method. In this article the author points out some basic features of the mainstream approaches taken to hot fusion power, as well as describe why z pinches are worth pursuing as a driver for a power reactor and how it may one day generate electrical power for mankind.
Date: March 1, 2000
Creator: DERZON,MARK S.
Partner: UNT Libraries Government Documents Department

X-ray emission from a high-atomic-number z-pinch plasma created from compact wire arrays

Description: Thermal and nonthermal x-ray emission from the implosion of compact tungsten wire arrays in 5-MA Saturn discharges is reported. The timing of multiple implosions and the thermal x-ray spectra (1 to 10 keV) agree with 2D radiation-hydrocode simulations. Nonthermal x-ray emission (10 to 100 keV) correlates with pinch spots distributed along the z-axis. The similarities of the measured nonthermal spectrum, yield, and pinch-spot emission with those of 0.8-MA, single- exploded-wire discharges on Gamble-II suggest a common nonthermal- production mechanism. Nonthermal x-ray yields are lower than expected from current scaling of Gamble II results, suggesting that implosion geometries are not as efficient as single-wire geometries for nonthermal x-ray production. The instabilities, azimuthal asymmetries, and inferred multiple implosions that accompany the implosion geometry lead to larger, more irregular pinch spots, a likely reason for reduced nonthermal efficiency. A model for nonthermal-electron acceleration across magnetic fields in highly- collisional, high-atomic-number plasmas combined with 1D hydrocode simulations of Saturn compact loads predicts weak nonthermal x-ray emission.
Date: June 1, 1996
Creator: Sanford, T.W.L.; Mosher, D. & De Groot, J.S.
Partner: UNT Libraries Government Documents Department

Time-dependent electron temperature diagnostics for high-power, aluminum z-pinch plasmas

Description: Time-resolved x-ray pinhole photographs and time-integrated radially-resolved x-ray crystal spectrometer measurements of azimuthally-symmetric aluminum-wire implosions suggest that the final pinch is composed of a hot dense plasma core surrounded by a cooler plasma halo. The slope of the free-bound x-ray continuum measured using filtered photoconducting diodes, provides a time-resolved, model-independent diagnostic of the core electron temperature. A simultaneous measurement of the time-resolved K-shell line spectra provides a diagnostic to indirectly measure the electron temperature of the plasma halo. Together, measurements from the two diagnostics lend support to a picture that also emerges from a 1-D Rad-Hydro model; namely, that of a plasma whose thermalization on axis produces steep radial gradients in temperature, where the temperatures are substantially in excess of a kilovolt in the core and below a kilovolt in the surrounding plasma halo.
Date: June 1, 1996
Creator: Sanford, T.W.L.; Nash, T.J. & Mock, R.C.
Partner: UNT Libraries Government Documents Department

NRL capillary Z-pinch experiment

Description: The current renewed interest in the dense linear z-pinch is due in large part to a recent Los Alamos Study which concluded that a z- pinch based reactor could produce 4.4 KJ of fusion energy per pulse for the modest input of 140 kJ per pulse, if a straight pinch could be maintained for 2 {mu}sec. Early attempts to achieve suitable high density z-pinches were of the implosion type which produced hollow pressure profiles that quickly resulted in disruptive m = 0 instabilities. These instabilities are not found in the gas embedded pinch in which an initially small diameter plasma is kept in radial equilibrium by following a prescribed current waveform. Unfortunately, these pinches are prone to a rapid accretion of the surrounding gas during the early stages of formation. Our approach is to form the pinch inside small diameter quartz capillaries filled with neutral hydrogen. This fixes the line density. By driving currents through the pinch at a rate that exceeds that necessary for radial equilibrium, we expect the pinch to contract away from the walls and be subject to compressional, as well as ohmic heating. This contraction will, of course, produce a plasma between the pinch and the capillary wall, but we anticipate this ``corona`` will be kept at a low temperature (i.e., high resistance) by radiation and hence shunt only a small fraction of the pinch current. We also expect negligible impurities in the pinch as the classical mixing time will be much longer than the pinch duration at the densities (10{sup 21}- 10{sup 22} ions/cm{sup 3}) and magnetic fields (1 - 10 MG) involved. However, we do expect the presence of the dense corona to reduce the growth rate of the m = 1 instability. Our results demonstrate that a z-pinch can be formed inside a ...
Date: December 31, 1984
Creator: Sethian, J.D.; Gerber, K.A.; Robson, A.E. & DeSilva, A.W.
Partner: UNT Libraries Government Documents Department

The role of Z-pinches and related configurations in magnetized target fusion

Description: The use of a magnetic field within a fusion target is now known as Magnetized Target Fusion in the US and as MAGO (Magnitnoye Obzhatiye, or magnetic compression) in Russia. In contrast to direct, hydrodynamic compression of initially ambient-temperature fuel (e.g., ICF), MTF involves two steps: (a) formation of a warm, magnetized, wall-confined plasma of intermediate density within a fusion target prior to implosion; (b) subsequent quasi-adiabatic compression and heating of the plasma by imploding the confining wall, or pusher. In many ways, MTF can be considered a marriage between the more mature MFE and ICF approaches, and this marriage potentially eliminates some of the hurdles encountered in the other approaches. When compared to ICF, MTF requires lower implosion velocity, lower initial density, significantly lower radial convergence, and larger targets, all of which lead to substantially reduced driver intensity, power, and symmetry requirements. When compared to MFE, MTF does not require a vacuum separating the plasma from the wall, and, in fact, complete magnetic confinement, even if possible, may not be desirable. The higher density of MTF and much shorter confinement times should make magnetized plasma formation a much less difficult step than in MFE. The substantially lower driver requirements and implosion velocity of MTF make z-pinch magnetically driven liners, magnetically imploded by existing modern pulsed power electrical current sources, a leading candidate for the target pusher of an MTF system.
Date: July 10, 1997
Creator: Lindemuth, I.R.
Partner: UNT Libraries Government Documents Department

Filtered x-ray diode diagnostics fielded on the Z-accelerator for source power measurements

Description: Filtered x-ray diode, (XRD), detectors are used as primary radiation flux diagnostics on Sandia`s Z-accelerator, which generates nominally a 200 TW, 2 MJ, x-ray pulse. Given such flux levels and XRD sensitivities the detectors are being fielded 23 meters from the source. The standard diagnostic setup and sensitivities are discussed. Vitreous carbon photocathodes are being used to reduce the effect of hydrocarbon contamination present in the Z-machine vacuum system. Nevertheless pre- and post-calibration data taken indicate spectrally dependent changes in the sensitivity of these detectors by up to factors up to 2 or 3.
Date: June 2, 1998
Creator: Chandler, G.A.; Deeney, C. & Cuneo, M.
Partner: UNT Libraries Government Documents Department

Wire array z-pinch insights for high x-ray power generation

Description: The discovery that the use of very large numbers of wires enables high x-ray power to be generated from wire-array z-pinches represents a breakthrough in load design for large pulsed power generators, and has permitted high temperatures to be generated in radiation cavities on Saturn. In this paper, changes in x-ray emission characteristics as a function of wire number, array mass, and load radius, for 20-mm-long aluminum arrays on Saturn that led to these breakthrough hohlraum results, are discussed and compared with a few related emission characteristics of high-wire-number aluminum and tungsten arrays on Z. X=ray measurement comparisons with analytic models and 2-D radiation-magnetohydrodynamic (RMHC) code simulations in the x-y and r-z planes provide confidence in the ability of the models and codes to predict future x-ray performance with very-large-number wire arrays.
Date: August 1, 1998
Creator: Sanford, T.W.L.; Mock, R.C. & Nash, T.J.
Partner: UNT Libraries Government Documents Department

Absolute, soft x-ray calorimetry on the Z facility at Sandia National Laboratories

Description: Simple and reliable x-ray fluence measurements, in addition to time-resolved diagnostics, are needed to understand the physics of hot Z-pinch plasmas. A commercially available laser calorimeter has been modified for measuring soft x-ray fluence from the Z facility at Sandia National Laboratories. The x-ray absorber of this calorimeter is an aluminum disk, attached to a two-dimensional thermopile and surrounded by an isoperibol shroud. The time-integral and the maximum of the thermopile voltage signal are both proportional to the x-ray energy deposited. Data are collected for 90 seconds, and the instrument has, thus far, been used in the 1--25 mJ range. A wider dynamic measuring range for x-ray fluence (energy/area) can be achieved by varying the area of the defining aperture. The calorimeter is calibrated by an electrical substitution method. Calibrations are performed before and after each x-ray experiment on the Z facility. The calibration of the time-integral of the thermopile voltage vs. energy deposited (or the peak of thermopile voltage vs. energy deposited) is linear with zero offset at the 95% confidence level. The irreproducibility of the calibration is <2%, and the imprecision in the measurement of the incident x-ray energy (inferred from signal noise and the calibration) is estimated to be {approximately}0.9 mJ (95% confidence level). The inaccuracy is estimated at {+-}10%, due to correctable systematic errors (e.g., baseline shifts). Comparisons have been made of the calorimeter to time-resolved x-ray diagnostics, e.g., bolometers and XRD (x-ray diode) arrays, by integrating the flux measured by these instruments over time.
Date: May 1, 1998
Creator: Fehl, D.L.; Muron, D.J.; Leeper, R.J.; Chandler, G.A.; Deeney, C. & Spielman, R.B.
Partner: UNT Libraries Government Documents Department

Pulsed Power Fusion Program update

Description: The US Department of Energy has supported a substantial research program in Inertial Confinement Fusion (ICF) since the early 1970s. Over the course of the ensuing 25 years, pulsed power energy, efficiency, and relatively low cost of the technology when compared to the mainline ICF approach involving large glass lasers. These compelling advantages of pulsed power, however, have been tempered with the difficulty that has been encountered in concentrating the energy in space and time to create the high energy and power density required to achieve temperatures useful in indirect drive ICF. Since the Beams `96 meeting two years ago, the situation has changed dramatically and extremely high x-ray power ({approximately}290 TW) and energy ({approximately}1.8 MJ) have been produced in fast x-pinch implosions on the Z accelerator. These sources have been utilized to heat hohlraums to >150 eV and have opened the door to important ICF capsule experiments.
Date: June 1, 1998
Creator: Quintenz, J.P.; Adams, R.G. & Allshouse, G.O.
Partner: UNT Libraries Government Documents Department

Application of 2-D simulations to hollow z-pinch implosions

Description: The application of simulations of z-pinch implosions should have at least two goals: first, to properly model the most important physical processes occurring in the pinch allowing for a better understanding of the experiments and second, provide a design capability for future experiments. Beginning with experiments fielded at Los Alamos on the Pegasus 1 and Pegasus 2 capacitor banks, the authors have developed a methodology for simulating hollow z-pinches in two dimensions which has reproduced important features of the measured experimental current drive, spectrum, radiation pulse shape, peak power and total radiated energy. This methodology employs essentially one free parameter, the initial level of the random density perturbations imposed at the beginning of the 2-D simulation, but in general no adjustments to other parameters are required. Currently the authors are applying this capability to the analysis of recent Saturn and PBFA-Z experiments. The code results provide insight into the nature of the pinch plasma prior to arrival on-axis, during thermalization and development after peak pinch time. Among other things, the simulation results provide an explanation for the production of larger amounts of radiated energy than would be expected from a simple slug-model kinetic energy analysis and the appearance of multiple peaks in the radiation power. The 2-D modeling has also been applied to the analysis of Saturn dynamic hohlraum experiments and is being used in the design of this and other Z-Pinch applications on PBFA-Z.
Date: December 1, 1997
Creator: Peterson, D.L.; Bowers, R.L. & Brownell, J.H.
Partner: UNT Libraries Government Documents Department

Spatially and temporally resolved crystal spectrometer for diagnosing high temperature pinch plasmas on Z

Description: The authors have developed a spatially and temporally resolved crystal spectrometer for analyzing a variety of pinch experiments on Z. The spectrometer uses a convex curved crystal to disperse spectra onto a flat microchannel plate framing camera detector. A single wide, 1 cm, strip on the MCP is gated to provide temporal resolution. The spectral range governed by the 4 cm length of the MCP strip varies with the central Bragg angle and crystal. For a KAP crystal a typical range is 1500 to 2000 eV. This range can be shifted by translating the crystal along the optical axis to access different Bragg angles. The spectrometer can therefore measure K shell spectra of a wide variety of elements such as Al, Ti, and Fe. The short 1 cm width of the strip is spatially resolved with an imaging cross slit. With a 500 microns cross slit and magnification 1 the spatial resolution at the pinch is 1 mm. The instrument may also be fielded with 7 time frames using a 7 strip-line microchannel plate as the detector by sacrificing the spatial resolution. The authors will present data obtained from an aluminum pinch on Z.
Date: June 1, 1998
Creator: Nash, T.; Derzon, M.; Leeper, R.; Jobe, D.; Hurst, M. & Seamen, J.
Partner: UNT Libraries Government Documents Department

Axial diagnostic package for Z

Description: The authors have developed and fielded an axial diagnostic package for the 20 MA, 100 ns, z-pinch driver Z. The package is used to diagnose dynamic hohlraum experiments which require an axial line of sight. The heart of the package is a reentrant cone originally used to diagnose ion-beam-driven hohlraums on PBFA-H. It has one diagnostic line of sight at 0 degrees, 4 at 6 degrees, and 4 at 9 degrees. In addition it has a number of viewing, alignment, and vacuum feedthrough ports. The front of the package sits approximately 5 feet from the pinch. This allows much closer proximity to the pinch, with inherently better resolution and signal, than is presently possible in viewing the pinch from the side. Debris that is preferentially directed along the axis is mitigated by two apertures for each line of sight, and by fast valves and imaging pinholes or cross slits for each diagnostic. In the initial run with this package they fielded a time resolved pinhole camera, a five-channel pinhole-apertured x-ray diode array, a bolometer, a spatially resolved time-integrated crystal spectrometer, and a spatially and temporally resolved crystal spectrometer. They present data obtained from these diagnostics in the dynamic hohlraum research conducted on Z.
Date: June 1, 1998
Creator: Nash, T.J.; Derzon, M.S. & Chandler, G.
Partner: UNT Libraries Government Documents Department

Wire-number effects on high-power annular z-pinches and some characteristics at high wire number

Description: Characteristics of annular wire-array z-pinches as a function of wire number and at high wire number are reviewed. The data, taken primarily using aluminum wires on Saturn are comprehensive. The experiments have provided important insights into the features of wire-array dynamics critical for high x-ray power generation, and have initiated a renaissance in z-pinches when high numbers of wires are used. In this regime, for example, radiation environments characteristic of those encountered during the early pulses required for indirect-drive ICF ignition on the NIF have been produced in hohlraums driven by x-rays from a z-pinch, and are commented on here.
Date: May 23, 2000
Creator: SANFORD,THOMAS W. L.
Partner: UNT Libraries Government Documents Department

X-1: The challenge of high fusion yield

Description: In the past three years, tremendous strides have been made in x-ray production using high-current z-pinches. Today, the x-ray energy and power output of the Z accelerator (formerly PBFA II) is the largest available in the laboratory. These z-pinch x-ray sources have great potential to drive high-yield inertial confinement fusion (ICF) reactions at affordable cost if several challenging technical problems can be overcome. Technical challenges in three key areas are discussed in this paper: (1) the design of a target for high yield, (2) the development of a suitable pulsed power driver, and (3) the design of a target chamber capable of containing the high fusion yield.
Date: June 1, 1998
Creator: Cook, D.L.; Ramirez, J.J. & Raglin, P.S.
Partner: UNT Libraries Government Documents Department

The effect of load thickness on Rayleigh-Taylor mitigation in high velocity, annular z pinch implosion

Description: Numerical calculations have been performed to investigate the role that load thickness may play in the performance of fast annular z pinch implosions. In particular, the effects of load thickness on the mitigation of the magnetically-driven Rayleigh-Taylor (RT) instability and energy coupling between the load and generator are addressed. using parameters representative of the Z accelerator [R.B.Spielman et al., Phys.Plasmas, 5, 2105 (1998)] at Sandia National Laboratories, two dimensional magnetohydrodynamic (MHD) simulations show that increased shell thickness results in lower amplitude, slightly longer wavelength RT modes. In addition, there appears to be an optimum in load velocity which is directly associated with the thickness of the sheath and subsequent RT growth. Thin, annular loads, which should couple efficiently to the accelerator, show a large reduction in implosion velocity due to extreme RT development and increased load inductance. As a consequence, thicker loads on the order of 5 mm, couple almost as efficiently to the generator since the RT growth is reduced. This suggests that z-pinch loads can be tailored for different applications, depending on the need for uniformity or high powers.
Date: May 16, 2000
Creator: DOUGLAS,MELISSA R.; DEENEY,CHRISTOPHER & RODERICK,NORMAN F.
Partner: UNT Libraries Government Documents Department

Fusion with Z-pinches

Description: In the past thirty-six months, great progress has been made in x-ray production using high-current z-pinches. Today, the x-ray energy and power output of the Z accelerator (formerly PBFA-II) is the largest available in the laboratory. These z-pinch x-ray sources have the potential to drive high-yield ICF reactions at affordable cost if several challenging technical problems can be overcome. In this paper, the recent technical progress with Z-pinches will be described, and a technical strategy for achieving high-yield ICF with z-pinches will be presented.
Date: June 1, 1998
Creator: Cook, D.
Partner: UNT Libraries Government Documents Department

Sheath broadening in imploding z-pinches due to large-bandwidth Rayleigh-Taylor instability

Description: The magnetic Rayleigh-Taylor (RT) instability has been predicted and observed to cause breakup of the plasma sheath in imploding Z-pinches. In this work we show that for the type of density profile encountered in strongly radiating pinches, instability at very short wavelengths grows to the non-linear stage and seeds progressively longer wavelengths. The result is a self-similar broadening of the sheath as found for mix layers in fluid RT unstable systems.
Date: June 4, 1996
Creator: Hammer, J.H.; Eddleman, J.L.; Tabak, M.; Toor, A.; Zimmerman, G.B. & De Groot, J.S.
Partner: UNT Libraries Government Documents Department

The prospect for fusion energy with light ions

Description: Intense ion beams may be the best option for an Inertial Fusion Energy (IFE) driver. While light ions may be the long-term pulsed power approach to IFE, the current economic climate is such that there is no urgency in developing fusion energy sources. Research on light ion beams at Sandia will be suspended at the end of this fiscal year in favor of z-pinches studying ICF target physics, high yield fusion, and stewardship issues. The authors document the status of light ion research and the understanding of the feasibility of scaling light ions to IFE.
Date: September 1, 1998
Creator: Mehlhorn, T.A.; Adams, R.G. & Bailey, J.E.
Partner: UNT Libraries Government Documents Department

Accurate, finite-volume methods for 3D MHD on unstructured Lagrangian meshes

Description: Previous 2D methods for magnetohydrodynamics (MHD) have contributed both to development of core code capability and to physics applications relevant to AGEX pulsed-power experiments. This strategy is being extended to 3D by development of a modular extension of an ASCI code. Extension to 3D not only increases complexity by problem size, but also introduces new physics, such as magnetic helicity transport. The authors have developed a method which incorporates all known conservation properties into the difference scheme on a Lagrangian unstructured mesh. Because the method does not depend on the mesh structure, mesh refinement is possible during a calculation to prevent the well known problem of mesh tangling. Arbitrary polyhedral cells are decomposed into tetrahedrons. The action of the magnetic vector potential, A {center_dot} {delta}l, is centered on the edges of this extended mesh. For ideal flow, this maintains {del} {center_dot} B = 0 to round-off error. Vertex forces are derived by the variation of magnetic energy with respect to vertex positions, F = {minus}{partial_derivative}W{sub B}/{partial_derivative}r. This assures symmetry as well as magnetic flux, momentum, and energy conservation. The method is local so that parallelization by domain decomposition is natural for large meshes. In addition, a simple, ideal-gas, finite pressure term has been included. The resistive diffusion part is calculated using the support operator method, to obtain an energy conservative, symmetric method on an arbitrary mesh. Implicit time difference equations are solved by preconditioned, conjugate gradient methods. Results of convergence tests are presented. Initial results of an annular Z-pinch implosion problem illustrate the application of these methods to multi-material problems.
Date: October 1, 1998
Creator: Barnes, D.C. & Rousculp, C.L.
Partner: UNT Libraries Government Documents Department

Wire array z-pinch insights for high X-ray power generation

Description: The discovery that the use of very large numbers of wires enables high x-ray power to be generated from wire-array z-pinches represents a breakthrough in load design for large pulsed power generators, and has permitted high temperatures to be generated in radiation cavities on Saturn and Z. In this paper, changes in x-ray emission characteristics as a function of wire number, array mass, and load radius, for 20-mm-long aluminum arrays on Saturn that led to these breakthrough hohlraum results, are discussed and compared with a few related emission characteristics of high-wire-number aluminum and tungsten arrays on Z. X-ray measurement comparisons with analytic models and 2-D radiation-magnetohydrodynamic (RMHC) code simulations in the x-y and r-z planes provide confidence in the ability of the models and codes to predict future x-ray performance with very-large-number wire arrays.
Date: 1998
Creator: Sanford, T. W. L.; Marder, B. M. & Desjarlais, M. P.
Partner: UNT Libraries Government Documents Department

Measurement of emission diameter as a function of time on foam z- pinch plasmas

Description: We have developed a streaked imaging capability to make time-resolved measurements of the emission size for low density foam z-pinches. By lens coupling visible emission from the z-pinch target to an array of fiber optics we obtained the emission profile in the visible as a function of time with radial resolution of 300 {mu}m. To measure the emission at temperatures greater than {approx}40 eV the source was slit-imaged or pin-hole imaged onto an x-ray filtered scintillator. Non-uniformities in both visible and x-ray emission were observed. We describe the diagnostics, the image unfold process, and results from the instrument for both visible and x-ray measurements.
Date: May 14, 1996
Creator: Lazier, S.E.; Barber, T.L.; Derzon, M.S. & Kellogg, J.W.
Partner: UNT Libraries Government Documents Department