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AbstractAbstract

[en] On the basis of the exact numerical solution of the Euler--Lagrange equations arising in the method of the energy-density functional we analyze the theorem on contact forces within the framework of the sudden approximation. The proximity function obtained is in agreement with the results of calculations of other authors and can be used for the construction of the ion--ion potential

Primary Subject

Source

(English). Cover-to-cover Translation of Yadernia Fizika (USSR). Cover-to-cover translation of Yadernaya Fizika (USSR).

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Journal Article

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Translation

Journal

Soviet Journal of Nuclear Physics (English Translation); ISSN 0038-5506; ; CODEN SJNCA; v. 50(4); p. 616-620

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Valance, A.; Simons, G.

International conference on the physics of electronic and atomic collisions. 10th. Paris, 21-27 July 1977

International conference on the physics of electronic and atomic collisions. 10th. Paris, 21-27 July 1977

AbstractAbstract

No abstract available

Primary Subject

Source

CEA, 75 - Paris (France); v. 2 p. 744-745; ISBN 2-7272-0021-8; ; 1977; v. 2 p. 744-745; Commissariat a l'Energie Atomique; Paris, France; 10. International conference on the physics of electronic and atomic collisions (ICPEAC); Paris, France; 21 - 27 Jul 1977; Books of abstracts commercially available from North-Holland, Amsterdam, the Netherlands; Published in abstract form only.

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AbstractAbstract

[en] The process of the two-electron resonant charge exchange in slow ion-ion collisions is considered in the framewrk of the asymptotic aprroach with account of the deviations of colliding particle trajectories from rectilinear motion. A quasi-classical approximation that holds for smaller intranuclear distances and provides for more accurate result, as compared to the ordinary asymptotic method, has been used to calculate the potential of the two-electron charge-exchange interaction. The results obtained are compared with calculations of other authors

Original Title

Rezonansnaya dvukh-ehlektronnaya perezaryadka v ion-ionnykh stolknoveniyakh

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Source

For English translation see the journal Ukrainian Physics Journal (USA).

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Journal Article

Journal

Ukrainskij Fizicheskij Zhurnal; ISSN 0503-1265; ; v. 29(3); p. 405-408

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AbstractAbstract

[en] By appeal to a Thomson-style treatment of recombination, it is shown that the rate for recombination of ions generated with uniform frequency within a reaction volume is a factor of 9/4 times greater than the rate for recombination of ions which approach each other from infinite separation. A valuable relationship connecting the two problems is uncovered. The analysis is pertinent to recombination involving dilute and high degrees of ionisation. (author)

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Journal Article

Journal

Journal of Physics. B, Atomic and Molecular Physics; ISSN 0022-3700; ; v. 18(15); p. L531-L537

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Wiese, W.L.

National Bureau of Standards, Washington, DC (USA)

National Bureau of Standards, Washington, DC (USA)

AbstractAbstract

[en] Brief descriptions of work are given for each of the following topics: (1) identification of atomic spectral lines, (2) atomic energy level compilations, (3) transition rate measurements with the theta pinch and TEXT experiments, (4) dielectronic recombination rates, (5) electron-ion collision experiments, (6) electron impact excitation theory, and (7) for uv radiometric standards

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Source

1983; 10 p; Available from NTIS, PC A02/MF A01 as DE83014022

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Report

Literature Type

Progress Report

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Diamond, P.H.; Hahm, T.S.; Tang, W.M.; Lee, W.W.; Lin, Z.

Princeton Plasma Physics Lab., NJ (United States). Funding organisation: USDOE Office of Energy Research (ER) (United States)

Princeton Plasma Physics Lab., NJ (United States). Funding organisation: USDOE Office of Energy Research (ER) (United States)

AbstractAbstract

[en] Results from 3D global gyrokinetic particle simulations of ion temperature gradient driven microturbulence in a toroidal plasma show that the ion thermal transport level in the interior region exhibits significant dependence on the ion-ion collision frequency even in regimes where the instabilities are collisionless. This is identified as arising from the Coulomb collisional damping of turbulence-generated zonal flows

Primary Subject

Source

1 Oct 1999; 4 p; AC02-76CH03073; Also available from OSTI as DE00013839; PURL: https://www.osti.gov/servlets/purl/13839-OyqLas/webviewable/

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Report

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Nesbitt, B.

Queen's Univ., Belfast (United Kingdom)

Queen's Univ., Belfast (United Kingdom)

AbstractAbstract

[en] Historically, the theoretical tool-box used to study heavy-particle atomic collisions was divided into two broad areas of research: (i) Close-coupling methods based on an expansion of wavefunctions in terms of a set of functions chosen to describe the electronic coordinates of the colliding atomic systems. (ii) Perturbative methods such as the Born series. The first approach was generally believed to be valid for low-energy collisions and the second for high-energy-collisions. However, the terms low and high are quite ambiguous in this context and require further clarification. The ratio of the projectile velocity, υ, to that of the orbital electron of interest in the target, υ

_{e}, provides adequate guidance in categorising low- and high-energy collisions, that is low refers to υ/υ_{e}<∼ 1 a.u. for high, υ/υ_{e}>∼ 1 a.u. In high-energy heavy particle collisions, ionization is the dominant process followed by possible excitation of the target. In contrast, in low- to intermediate-energy collisions it is not possible to single out a dominant channel in general, because often many inelastic channels couple with one another, exchanging flux and phase in a complex manner. In this thesis we examine these two areas of heavy-particle collisions. In part I we concentrate on low-energy collisions. Chapter one introduces the Stokes phenomenon and the JWKB approximation. The JWKB method is considered a valuable tool within the theoretical treatment of atomic processes. Very often, when tracing JWKB solutions through the complex plane, one will encounter the apparent discontinuities that give rise to the Stokes phenomenon. In chapter one we discuss such situations within the context of a one-dimensional problem. Then in chapter two, after introducing the equations of motion for low-energy charge exchange for ion-atom collisions, we consider the four- transit ion-point model and the Zwaan-Stueckelberg phase-integral method. This leads to the derivation of the semiclassical two-state S matrix within diabatic and adiabatic representations. In chapter 3 we examine the four-transition-point exponential model of Nikitin which is used to approximate certain types of low-energy ion-atom collisions. Analytic approximations for the generalised transition probability are obtained and compared with numerical calculations. Similarly, in chapter 4 we consider another four-transition-point model, namely the Parabolic model. A completely new four-transition-point model is introduced in chapter 5. This model is initially developed within the context of one-dimensional scattering. This then allows us to attempt to construct suitable Hamiltonian interactions that satisfy our model. Part II of this thesis is concerned with the single-ionization of atomic and molecular targets by ion impact at intermediate energies. In chapter 6 we introduce basic descriptions of the problem and discuss the main mechanisms involved in the ionization process. The obvious starting point is to examine the First-Born approximation and consider its deficiencies. To account for these deficiencies we then examine distorted-wave theories such as the continuum-distorted-wave approximation and the eikonal-initial-state model. Chapter 7 concentrates on the continuum-distorted-wave eikonal-initial-state model and its application to the single-ionization of atomic and molecular hydrogen and helium by proton impact at intermediate energies. We study the ejected-electron spectrum by calculating double-differential cross sections and focus attention on the role of saddle-point trapping of ejected-electrons during the ionization process. (author)Primary Subject

Source

Sep 1999; [vp.]; Available from British Library Document Supply Centre- DSC:DXN030975; Thesis (Ph.D.)

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Miscellaneous

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Thesis/Dissertation

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AbstractAbstract

[en] This paper confirms that ExB shearing from toroidally symmetric (toroidal mode number n=0) 'radial modes' provides the dominant nonlinear saturation mechanism for drift wave (n≠0) turbulence, which in turn nonlinearly drives the modes. In common usage, this is loosely referred to as the 'drift wave-zonal flow paradigm' for nonlinear saturation despite the fact that radial modes have several components distinguished in this paper: a residual or zero mean frequency 'zonal flow' part and an oscillatory 'geodesic acoustic mode' (GAM) part. Linearly, the zonal flows (and GAMs) are weakly damped only by ion-ion collisions, while the GAMs are strongly Landau damped only at low safety factor q. At high q the Hinton-Rosenbluth residual flow from an impulse vanishes and only the weakly damped GAMs remain. With the linear physics and driving rates of the finite-n transport modes unchanged, this paper argues that GAMs are only somewhat less effective than the residual zonal flows in providing the nonlinear saturation, and in some cases ExB shearing from GAMs (or at least the GAM physics) appears to dominate: transport appears to be nearly linear in the GAM frequency. By deleting the drift wave-drift wave nonlinear coupling, it is found that drift wave-radial mode nonlinear coupling triads account for most of the nonlinear saturation. Furthermore, the ExB shear components of the radial modes nonlinearly stabilize the finite-n modes, while the diamagnetic components nonlinearly destabilize them. Finally, from wave number spectral contour plots of the time average nonlinear entropy transfer function (and rates), it is shown that the peak in entropy generation coincides with the peak in transport production, while entropy dissipation (like Landau damping) is spread equally over all n modes (including n=0). Most of these conclusions appear to hold about equally well for all types of drift wave turbulence.

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(c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)

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Journal Article

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AbstractAbstract

No abstract available

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Source

1974; 1 p; 7. European conference on plasma production by high power lasers; Garching, F.R. Germany; 22 Apr 1974; Short communication only. Published in the program book of abstracts.

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Report

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Chen, C.Y.; Landers, A.; Giese, J.P.

Thirteenth international conference on the application of accelerators in research and industry

Thirteenth international conference on the application of accelerators in research and industry

AbstractAbstract

[en] A facility to study collisions between two multiply charged ions is under construction at the Macdonald Lab. Ions from the KSU CRYEBIS will be collided with ions from a 5 GHz ECR ion source. The two ion beams will intersect at 90 degrees. The ECR beam will be decelerated to a few hundred eV per charge in order to enhance the effective target density. Ion-optics simulations including space charge effects indicate that it is possible to decelerate the slow, intense ECR beam and maintain both a reasonable focus at the collision region and 100% transmission of the collision products. The ECR ion source has been installed and is undergoing developmental testing. The vacuum system at the collision region is complete and the deceleration columns are being fabricated. Initial ion-ion collision tests should begin in the next few months

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Duggan, J.L.; Morgan, I.L. (eds.); 201 p; 1994; p. 92-93; University of North Texas; Denton, TX (United States); 13. international conference on the application of accelerators in research and industry; Denton, TX (United States); 7-10 Nov 1994

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Book

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