Related Plasma Phenomena Research Articles

Sheared Plasma Flow Generation: A New Measure for Stellarator Optimization

Recent stellarator optimization efforts have targeted transport measures such as quasi-symmetry, effective ripple, and alignment of particle guiding center orbits with flux surfaces. This has resulted in significant reductions in neoclassical losses so that, at least for near-term experiments, the neoclassical transport of particles and energy can be made small compared to anomalous transport. However, momentum transport properties within magnetic flux surfaces provide an additional dimension for characterizing optimized stellarators. The momentum and flow damping features of optimized stellarators can vary widely, depending on their magnetic structure, ranging from systems with near-tokamak-like properties where toroidal flows dominate to those in which poloidal flows dominate and toroidal flows are suppressed. A set of tools has been developed for self-consistently evaluating the flow characteristics of different stellarators. Application of this model to existing and planned devices indicates that plasma flow properties vary significantly. Comparisons across devices can aid in unfolding the interplay between anomalous and neoclassical damping effects as well as the impact of momentum transport properties on related plasma phenomena such as turbulence suppression, shielding of resonant magnetic error fields, and impurity transport.

Laser Interaction and Related Plasma Phenomena

Computations are to be performed using the laser driven inertial fusion energy option based on volume ignition with the natural adiabatic self-similarity compression and expansion hydrodynamics [1]. The numerical work includes the establishing of a multi-branch reaction code to be used for simultaneous fusion reactions of D-D, D-T D-He3 and mutual nuclear reaction products. This will permit the studies of neutron lean reactions as well as tritium-rich cases. The D-T reactions will stress the recent new results on one step laser fusion [2] as an alternative to the two-step fast ignitor scheme whose difficulties with new physics phenomena at petawatt laser interaction are more and more evident [3].

Laser interaction and related plasma phenomena

Report on the Thirteenth International Conference held at the Naval Postgraduate School, Monterey, California, United States of America, 13-18 April 1997.

S. Nakai and G.H. Miley, Eds., Laser Interaction and Related Plasma Phenomena(12th International Conference, Osaka, April 1995), AIP Conference Proceedings 369 Part One and Part Two, American Institute of Physics, New York (1996), 1426 pages.

S. Nakai and G.H. Miley, Eds., Laser Interaction and Related Plasma Phenomena(12th International Conference, Osaka, April 1995), AIP Conference Proceedings 369 Part One and Part Two, American Institute of Physics, New York (1996), 1426 pages. - Volume 15 Issue 1

Free nuclei gamma-ray lasing

We discuss two different approaches for observing induced gamma-ray emission of nuclei, departing from known attempts to use the Moessbauer transitions that have so far proven unsuccessful. Both approaches (presented at the 11th and 12th International Conferences on Laser Interaction and Related Plasma Phenomena) are based on the elimination of pernicious influence of Doppler line-broadening in ensembles of free nuclei, particularly in atom and ion beams.

Laser interaction and related plasma phenomena (Report on the 9th International Workshop, Monterey, CA, 6-10 November 1989)

The 9th International Workshop on Laser Interaction and Related Plasma Phenomena was held from 6 to 10 November 1989, at Naval Postgraduate School, Monterey, California. This series of meetings began in 1969 and it is the longest series of meetings in this field in the USA. It is, in fact, the longest series with published proceedings that document the advances and the growth of this dynamic field of physics and technology.

Numerical simulation of laser–target interaction and blast wave formation

A numerical hydrodynamics chemistry model to simulate the laser–target interaction experiment at the Naval Research Laboratory’s PHAROS [Laser Interaction and Related Plasma Phenomena (Plenum, New York, 1986), Vol. 7, p. 857] is presented. Both laser–target and debris–background interactions are modeled, solving mass continuity, total momentum, and separate ion and electron internal energy equations. The model is appropriate for background densities≥1 Torr. To accurately treat both the early-time planar ablation and the later spherical expansion of the blast wave, as well as the rear-side shock front, an oblate spheroidal coordinate system was adopted. The aluminum target ablates into and interacts with an ambient nitrogen gas, filling the facility chamber. The simulation models the target continuously from the solid state to the state of a highly ionized nonequilibrium plasma, including all charge states of aluminum and all charge states of the nitrogen background. The laser beam has a wavelength of 1 μ, a ∼5 nsec full width at half-maximum (FWHM), an intensity at the target surface ∼1013 W/cm2, and total energy varying from 20–100 J. The model accurately reproduces the measured time-of-flight profile and the mass of ablated aluminum. Expansion of the blast wave in the model follows the ideal Sedov relation until radiation losses force a deviation due to a failure in the constant energy assumption. In the shock wave region the simulations show electron density of a few times 1018 cm−3, temperatures ranging from 10–20 eV, and dominant nitrogen species of N+3 and N+4, all in agreement with experimental measurement. A calculated profile of electron density both in the shock and in the cavity region agree closely with experiment and imply an average aluminum charge state of 11 times ionized in the cavity out to late times, as predicted by the simulation described in this paper. The simulation suggests, also, that observed rear-side structuring is a result of a deceleration Rayleigh–Taylor instability. The model is capable of providing detailed predictions, which are presented, as to profiles of charge states, densities, and temperatures as a function of time; these predictions are not yet tested by experimental measurement.

Energy deposition and shock wave evolution from laser-generated plasma expansions

One-dimensional radiation-hydrodynamics calculations have been performed to study the structure and evolution of blast waves resulting from laser-generated plasma expansions. The results are compared with experimental data obtained at the Naval Research Laboratory [Laser Interaction and Related Plasma Phenomena (Plenum, New York, 1986), Vol. 7, pp. 857–877]. In these calculations, target ions expand into a stationary background gas with an initial pressure ranging from 25 mTorr–5 Torr. Because the stopping ranges of the target ions are comparable to the dimensions of the shock, the blast wave properties are sensitive to the ion stopping cross sections. In some calculations, the effects of radiation transport were neglected in order to assess its importance. The results presented in this paper are in generally good agreement with available experimental data, and indicate that the observed blast wave properties can be accounted for by using a classical collision model to describe the interaction between the target ions and the background plasma.

Laser interactions and related plasma phenomena (Report on the Eighth International Workshop on Laser Interaction, Monterey, CA, 26-30 October 1986)

The International Workshop on Laser Interactions and Related Plasma Phenomena is the oldest continuing series of meetings in the United States with published proceedings documenting much of the growth of this dynamic field. The meeting format is designed to provide an interactive atmosphere that encourages first disclosures along with in-depth critical reviews. The Eighth International Workshop was held at the Naval Postgraduate School at Monterey, California, 26-30 October 1986, under the continuing directorship of H. Hora (University of New South Wales) and G.H. Miley (University of Illinois). The local organizer was F. Schwirzke (Naval Postgraduate School).

Electron beam injection into space plasmas

A summary is given is given for eight poster papers presented at the Open Symposium on Active Experiments in Space Plasmas held at the XXIst General Assembly of URSI, 1984. These papers are concerned with electron beam injection into space plasmas and with its related plasma phenomena. A summary of interrelations of these papers is also given.

Book reviews

Abstract Modern Crystallography. I. Symmetry of Crystals, Methods of Structural Crystallography. By B. K. Vainstein. (Springer-Verlag, 1981.) [Pp. xviii + 399.] DM98; $46.70. The Creation. By P. W. Atkins. (W. H. Freeman, 1981.) [Pp. viii + 132.] £595. The Role of Coherent Structures in Modelling Turbulence and Mixing. Edited by J. Jimenez. (Springer-Verlag, 1981.) [Pp. xiii + 393.] DM47; $24.70. Level: Advanced. The New Solar System. Edited by J. K. Beatty, B. O'Leary and A. Chaikin, with an Introduction by Carl Sagan. (Cambridge University Press, 1981.) [Pp. 224.] Price £9.95. The Architecture of Solids. By G.E. Bacon. (Taylor & Francis Ltd, 1981.) [Pp. viii + 140.] £5.50. Scope: Interdisciplinary survey. Level: School/University borderline and general. Seventh International Conference on Numerical Methods in Fluid Dynamics, Stanford, 1980. Edited by W. C. Reynolds and R. W. Mac Cormack. (Springer-Verlag, 1981.) [Pp. viii + 485.] DM 52; $24.80. Laser Interaction and Related Plasma Phenomena. Edited by H. J. Schwartz, H. Hora, M. J. Lubin and B. Yaakobi (Plenum Press, 1981.) [Pp. vii + 850.] $75.00. Scope: State of the art in specific field. Level: Current research. The Theory of Magnetism, Volume 1. Statics and Dynamics. By D. C. Mattis. (Springer-Verlag, 1981.) [Pp. xv + 300.] DM72; $32.80. Scope: Textbook. Level: Postgraduate. Deep Water Gravity Waves. By B. J. West. (Springer-Verlag, 1981.) [Pp. vi + 341.] DM 33; $15.00. Scope: Monograph. Level: Postgraduate. Recent Progress in Many-Body Theories. Edited by J. G. Zabolitzky, M. Dellano, M. Fortes and J. W. Clark. (Springer-Verlag, 1981.) [Pp. viii + 479.] DM52; $24.80. Topics in Nuclear Physics. A Comprehensive Review of Recent Developments. In two volumes. Edited by T. T. S. Kuo and S. S. M. Wong. (Springer-Verlag, 1981.) Volume I. [Pp. xx + 567.] DM59; $26.90. Volume II. [Pp. viii + 511.] DM59; $26.90. Structure and Evolution of Normal Galaxies. Edited by S. M. Fall and D. Lynden-Bell. (Cambridge University Press, 1981.) [Pp. xiii + 272.] £15.00 Optical Bistability. Proceedings of the 1980 International Optical Bistability Conference, Asheville, N. Carolina, U.S.A. (Plenum Press, 1981.) [Pp. xi + 614.] $69.50 Nonequilibrium Thermodynamics and its Statistical Foundations. By H. J. Kreuzer. (Clarendon Press: Oxford University Press, 1981.) [Pp. xx + 438.] £45.00. The Earth. Its Birth and Growth. By M. Ozima. (Cambridge University Press, 1981.) [Pp. 117.] £10.50 Hardback; £3.95 paper. A Dictionary of Energy. By M. Counihan. (Routledge & Kegan Paul, 1981.) [Pp. 157.] £6.95. Mathematics and Physics. Yu I. Manin. (Birkhauser-Verlag, 1981.) [Pp. xii + 99.] Sw. fr. 22. Scope: Survey of relations between Mathematics and Physics. Level: Any level. Advances in Nuclear Physics. Volume 12. Edited by J. W. Negele and E. Vogt. (Plenum Press, 1981.) [Pp. xiii + 258.] $35.00. Scope: Nuclear matter. Particle scattering by complex nuclei. Level: Specialist. Field-Effect and Bipolar Power Transistor Physics. By A. Blicher. (Academic Press, 1981.) [Pp. xiv + 312.] £27.20; $41.00. Level: Undergraduate and first-year postgraduate. Point Defects in Semiconductors, I. Theoretical Aspects. By M. Lannoo and J. Bourgoin. Springer Series in Solid State Sciences, No. 22. (Springer-Verlag, 1981.) [Pp. xvii + 265.] Price DM 72; $32.80. Defects and Radiation Effects in Semiconductors, 1980. Edited by R. R. Hasiguti. Institute of Physics Conference Series, No. 59. (Institute of Physics, 1981.) [Pp. xiv + 571.] Price £39.00; $97.50. Atomic Physics, 7. Edited by D. Kleppner and F. M. Pipkin. (Plenum Press, 1981.) [Pp. x + 573.] $69.50. Scope: Mainly atoms, electrons and radiation. Level: Specialist/Postgraduate. Elements of Solid State Physics. By M. N. Rudden and J. Wilson. (John Wiley, 1981.) [Pp. xi + 186.] £14.50 Cloth, £5.95 Paper. Scope: General background to solid state devices. Level: Elementary undergraduate. Potential Energy Surfaces and Dynamics Calculations. Edited by Donald G. Truhlar. (Plenum, 1981.) [Pp. xii + 866.] $85.00. Scope: Symposium. Level: Specialist/postgraduate. Pulsed Neutron Scattering. By C. G. Windsor. (Taylor & Francis Ltd, 1981.) [Pp. xi + 432.] £25. Scope: State-of-the-art review. Level: Research.

Laser Interaction and Related Plasma Phenomena (Report on the 4th International Workshop, Troy, 1976)

One opportunity for exchanging information on Lasers, Plasma and Related Phenomena, such as Laser Compression for nuclear fusion or extremely high interaction intensities, has been the series of Workshop-Conferences organized at Rensselaer Polytechnic Institute beginning in 1969. The 4th meeting, 8–12 November, 1976, brought together more than 70 participants from 13 countries (Argentine, Australia, Brazil, Canada, England, France, Federal Republic of Germany, India, Israel, Italy, Japan, USA and the USSR), where 53 scientific papers were discussed under the sponsorship of RPI and ERDA.

A comparison of thermospheric neutral gas heating and related thermal and energetic plasma phenomena at high latitudes during geomagnetic disturbances

Simultaneous in situ measurements of energetic particle fluxes, ionospheric parameters, and neutral atmospheric parameters from the polar-orbiting satellite Esro 4 were made at altitudes in the range 250–500 km at middle and high latitudes. A study of changes in the parameters in both position and magnitude during geomagnetic disturbances in December 1972 and February 1973 showed three main regions of neutral atmosphere disturbance following the onset of magnetic activity indicated by the value of the Kp index. First, the largest effect was an enhancement of the N2 and Ar densities and reduction of the He density over the whole polar cap. Second, on the night side middle- to high-latitude region an enhancement of N2 density correlated with the zone of > 44-keV-electron flux was observed, and this N2 enhancement was correlated with the equatorward edge of the ionospheric plasma trough, the poleward edge of the latter being coincident with the equatorward edge of the 200-eV-electron flux zone. Third, on the day side a narrow region of enhanced N2 density was frequently observed at invariant latitudes of 70°–80°. This heating region generally coincided with a narrow plasma trough and a region of enhanced electron temperature.

Laser Interaction and Related Plasma Phenomena. Proceedings of the First Workshop. Rensselaer Polytechnic Institute, Hartford Graduate Center, June 1969. Edited by Helmut J. Schwarz and Heinrich Hora. Plenum Press1970. 522 pp. $25.00.

Laser Interaction and Related Plasma Phenomena. Proceedings of the First Workshop. Rensselaer Polytechnic Institute, Hartford Graduate Center, June 1969. Edited by Helmut J. Schwarz and Heinrich Hora. Plenum Press1970. 522 pp. $25.00.

Laser interaction and related plasma phenomena Edited by H. J. Schwarz and H. Hora. Pp xiv + 509. Plenum Publishing Corporation, New York. 1971. $25.00

Laser interaction and related plasma phenomena Edited by H. J. Schwarz and H. Hora. Pp xiv + 509. Plenum Publishing Corporation, New York. 1971. $25.00

Laser-Produced Plasmas. (Book Reviews: Laser Interaction and Related Plasma Phenomena. Proceedings of a workshop, East Windsor Hill, Conn., June 1969)

Laser-Produced Plasmas. (Book Reviews: Laser Interaction and Related Plasma Phenomena. Proceedings of a workshop, East Windsor Hill, Conn., June 1969)