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in creator/contributor: "Pearlstein, L. D."  
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TEBASCO user's guide

Description: TEBASCO is a Tandem mirror Equilibrium and BAllooning Stability COde. TEBASCO allows you to compute tandem-mirror MHD equilibria and to analyze both the flute-averaged and ballooning-mode stability of these equilibria. This stability analysis is directed toward the computation of marginal stability boundaries. Users of TEBASCO require a binary output file from the EFFI code which describes the vacuum magnetic field. In making this EFFI file the user will have defined a system of units for lengt… more
Date: September 22, 1983
Creator: Pearlstein, L. D.; Kaiser, T. B.; LoDestro, L.; Maron, N.; Nevins, W. M. & Willmann, P. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Spheromak Energy Transport Studies via Neutral Beam Injection

Description: Results from the SSPX spheromak experiment provide strong motivation to add neutral beam injection (NBI) heating. Such auxiliary heating would significantly advance the capability to study the physics of energy transport and pressure limits for the spheromak. This LDRD project develops the physics basis for using NBI to heat spheromak plasmas in SSPX. The work encompasses three activities: (1) numerical simulation to make quantitative predictions of the effect of adding beams to SSPX, (2) using… more
Date: February 11, 2008
Creator: McLean, H. S.; Hill, D. N.; Wood, R. D.; Jayakumar, J. & Pearlstein, L. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Studies of tandem mirror confinement

Description: This paper describes a number of physics studies relevant to tandem mirror confinement. We give the basic axial confinement laws and show that T/sub e/ depends critically upon end loss. Sufficient central-cell end loss can stabilize the drift-cyclotron loss-cone mode in the plugs, although the resultant T/sub e/ scaling is too slow for reactors. Minimum-B plugs stabilize flute MHD- and rotation-driven modes; local ballooning sets limits on ..beta.. > or equal to 0.5. Proper magnetic symmetry is… more
Date: July 10, 1978
Creator: Baldwin, D. E.; Cohen, R. H.; Foote, J. H.; Hall, L. S.; Kaiser, T. B.; Logan, B. G. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Field reversal in mirror machines

Description: This report discusses some of the physics issues anticipated in field-reversed mirrors. The effect of current cancellation due to electrons is described. An estimate is made of the required impurity level to maintain a field-reversed configuration. The SUPERLAYER code is used to simulate the high-..beta.. 2XIIB results, and favorable comparisons require inclusion of quasilinear RF turbulence. Impact of a quadrupole field on field-line closure and resonant transport is discussed. A simple self-c… more
Date: July 10, 1978
Creator: Pearlstein, L. D.; Anderson, D. V. & Boozer, A. H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Barrier-potential model

Description: A useful model for calculating the variation in the electron density, ion density, and ambipolar potential along magnetic field lines in the thermal barrier cell of a tandem mirror is presented.
Date: August 4, 1981
Creator: Pearlstein, L. D. & Nevins, W. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Toward a design for the ITER plasma shape and stability control system

Description: A design strategy for an integrated shaping and stability control algorithm for ITER is described. This strategy exploits the natural multivariable nature of the system so that all poloidal field coils are used to simultaneously control all regulated plasma shape and position parameters. A nonrigid, flux-conserving linearized plasma response model is derived using a variational procedure analogous to the ideal MHD Extended Energy Principle. Initial results are presented for the non-rigid plasma… more
Date: July 1, 1994
Creator: Humphreys, D. A.; Leuer, J. A.; Kellman, A. G.; Haney, S. W.; Bulmer, R. H.; Pearlstein, L. D. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Modeling results for a linear simulator of a divertor

Description: A divertor simulator, IDEAL, has been proposed by S. Cohen to study the difficult power-handling requirements of the tokamak program in general and the ITER program in particular. Projections of the power density in the ITER divertor reach {approximately} 1 Gw/m{sup 2} along the magnetic fieldlines and > 10 MW/m{sup 2} on a surface inclined at a shallow angle to the fieldlines. These power densities are substantially greater than can be handled reliably on the surface, so new techniques are req… more
Date: June 23, 1993
Creator: Hooper, E. B.; Brown, M. D.; Byers, J. A.; Casper, T. A.; Cohen, B. I.; Cohen, R. H. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Field and Current Amplification in the SSPX Spheromak

Description: Results are presented from experiments relating to magnetic field generation and current amplification in the SSPX spheromak. The SSPX spheromak plasma is driven by DC coaxial helicity injection using a 2MJ capacitor bank. Peak toroidal plasma currents of up to 0.7MA and peak edge poloidal fields of 0.3T are produced; lower current discharges can be sustained up to 3.5msec. When edge magnetic fluctuations are reduced below 1% by driving the plasma near threshold, it is possible to produce plasm… more
Date: October 8, 2002
Creator: Hill, D. N.; Blumer, R. H.; Cohen, B. I.; Hooper, E. B.; McLean, H. S.; Moller, J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Spheromak formation studies in SSPX

Description: We present results from the Sustained Spheromak Physics Experiment (SSPX) at LLNL, which has been built to study energy confinement in spheromak plasmas sustained for up to 2 ms by coaxial DC helicity injection. Peak toroidal currents as high as 600kA have been obtained in the 1m dia. (0.23m minor radius) device using injection currents between 200-400kA; these currents generate edge poloidal fields in the range of 0.2-0.4T. The internal field and current profiles are inferred from edge field m… more
Date: September 29, 2000
Creator: Hill, D. N.; Bulmer, R. H.; Cohen, B. L.; Hooper, E. B.; LoDestro, L. L.; Mattor, N. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electron Cyclotron Heating and Current Drive for Maintaining Minimum q in Negative Central Shear Discharges

Description: Toroidal plasmas created with negative magnetic shear in the core region offer advantages in terms of MHD stability properties. These plasmas, transiently created in several tokamaks, have exhibited high performance as measured by normalized stored energy and neutron production rates. A critical issue with extending the duration of these plasmas is the need to maintain the off-axis-peaked current distribution required to support the minimum in the safety factor q at large radii. We present equi… more
Date: April 24, 2003
Creator: Casper, T. A.; Kaiser, T. B.; Jong, R. A.; LoDestro, L. L.; Moller, J.; Pearlstein, L. D. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Alfven-ion-cyclotron instability in mirror machines

Description: Electrostatic instabilities occurring in mirror-confined ion velocity-distributions have been thoroughly investigated. The electromagnetic instability of greatest concern is the Alfven-ion-cyclotron (AIC) mode. In this work we investigate both convective and absolute growth, both in homogeneous plasma and in finite machines, for a variety of ion velocity-distributions. Good agreement is found with the results from the particle simulation code ''Superlayer''. Quasilinear effects are outlined and… more
Date: May 24, 1977
Creator: Watson, D. C.; Pearlstein, L. D. & Lodestro, L. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theoretical explanation of present mirror experiments and linear stability of larger scaled machines

Description: A quasilinear model for the evolution of the 2XIIB mirror experiment is presented and shown to reproduce the time evolution of the experiment. From quasilinear theory it follows that the energy lifetime is the Spitzer electron drag time for T/sub e/ approximately less than 0.1T/sub i/. By computing the stability boundary of the DCLC mode, with warm plasma stabilization, the electron temperature is predicted as a function of radial scale length. In addition, the effect of finite length correctio… more
Date: July 27, 1976
Creator: Berk, H. L.; Baldwin, D. E.; Cutler, T. A.; Lodestro, L. L.; Maron, N.; Pearlstein, L. D. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Computation of the bounce-average code

Description: The bounce-average computer code simulates the two-dimensional velocity transport of ions in a mirror machine. The code evaluates and bounce-averages the collision operator and sources along the field line. A self-consistent equilibrium magnetic field is also computed using the long-thin approximation. Optionally included are terms that maintain ..mu.., J invariance as the magnetic field changes in time. The assumptions and analysis that form the foundation of the bounce-average code are descri… more
Date: May 23, 1977
Creator: Cutler, T. A.; Pearlstein, L. D. & Rensink, M. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Calculation of Neutral Beam Injection into SSPX

Description: The SSPX spheromak experiment has achieved electron temperatures of 350eV and confinement consistent with closed magnetic surfaces. In addition, there is evidence that the experiment may be up against an operational beta limit for Ohmic heating. To test this barrier, there are firm plans to add two 0.9MW Neutral Beam (NB) sources to the experiment. A question is whether the limit is due to instability. Since the deposited Ohmic power in the core is relatively small the additional power from the… more
Date: June 13, 2006
Creator: Pearlstein, L. D.; Casper, T. A.; Hill, D. N.; LoDestro, L. L. & McLean, H. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Analysis and Modeling of DIII-D Hybrid Discharges and their Extrapolation to ITER

Description: Recent experiments on tokamaks around the world [1-5] have demonstrated discharges with moderately high performance in which the q-profile remains stationary, as measured by the motional Stark effect diagnostic, for periods up to several {tau}{sub R}. Hybrid discharges are characterize by q{sub min} {approx} 1, high {beta}{sub N}, and good confinement. These discharges have been termed hybrid because of their intermediate nature between that of an ordinary H-mode and advanced tokamak discharges… more
Date: June 16, 2006
Creator: Makowski, M. A.; Casper, T. A.; Jayakumar, R. J.; Pearlstein, L. D.; Petty, C. C. & Wade, M. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Quantitative Tests of ELMs as Intermediate N Peeling-Ballooning Modes

Description: OAK A271 QUANTITATIVE TESTS OF ELMS AS INTERMEDIATE N PEELING-BALLOONING MODES. Two of the major issues crucial for the design of the next generation tokamak burning plasma devices are the predictability of the edge pedestal height and control of the divertor heat load in H-mode configurations. Both of these are strongly impacted by edge localized modes (ELMs) and their size. A working model for ELMs is that they are intermediate toroidal mode number, n {approx} 5-30, peeling-ballooning modes d… more
Date: July 1, 2002
Creator: Lao, L. L.; Snyder, P. B.; Leonard, A. W.; Osborne, T. H.; Petrie, T. W.; Ferron, J. R. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Advanced steady-state operating scenarios

Description: The goal for advanced steady-state operation in ITER should be to demonstrate the operation of the plasma core for a steady-state fusion reactor. To accomplish this the authors must develop steady-state operating scenarios at high beta for high fusion power density, low auxiliary power requirements (Q{sub CD} {ge} 25, where Q{sub CD} {triple_bond}P fusion/P{sub CD} and P{sub DC} is the power required for sustaining the plasma current) for low recirculating power requirements, and at moderate sa… more
Date: December 2, 1993
Creator: Nevins, W. M.; Bulmer, R. H.; Pearlstein, L. D.; Haney, S. W. & Manickam, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Sustainment of Spheromak Pasmas in SSPX

Description: SSPX (Sustained Spheromak Physics eXperiment) was constructed to investigate the key physics issues of buildup and sustainment of spheromak plasmas with elevated electron temperature. Long pulse buildup to high magnetic field and temperature, at modest gun current, may point the way to a potentially simpler and more compact fusion reactor. Reported here are T{sub e} measurements in new magnetic flux geometries, results from sustainment experiments with {approx}1ms pulses, and power balance mode… more
Date: June 13, 2001
Creator: Stallard, B. W.; Hill, D. N.; Holcomb, C.; Hooper, E. B.; McLean, H. S.; Wood, R. D. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Route to High Temperatures by Current Amplification in the Sustained Spheromak Physics Experiment (SSPX)

Description: For the spheromak to be attractive as a reactor concept it would be necessary to sustain the configuration with a low recycling power, reflected in the current amplification factor: A{sub 1} = I{sub tor}/I{sub gun}, where I{sub tor} is the toroidal current and I{sub gun} is the gun current. It is understood that A{sub 1} needs to be around 60 for a reactor [1], although the highest obtained so far in the spheromak has been {approx}3 [2]. The spheromak is a simply connected toroidal confinement … more
Date: June 11, 2002
Creator: Woodruff, S.; Holbomb, C. T.; Stallard, B. W.; Hill, D. N.; Hooper, E. B.; McLean, H. S. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Hyper-resistivity Theory in a Cylindrical Plasma

Description: A model is presented for determining the hyper-resistivity coefficient that arises due to the presence of magnetic structures that appear in plasma configurations such as the reversed field pinch and spheromak. Emphasis is placed on modeling cases where magnetic islands pass from non-overlap to overlap regimes. Earlier works have shown that a diffusion-based model can give realistic transport scalings when magnetic islands are isolated, and this formalism is extended to apply to the hyper-resis… more
Date: February 27, 2001
Creator: Berk, H. L.; Fowler, T. K.; LoDestro, L. L. & Pearlstein, L. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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