Inverse Populations of Multicharged Ion Levels in a Z-Pinch Plasma as a Result of Interaction of Plasma Beams with Neutral or Low-Ionized Gas Targets

Churilov, S S; Dorokhin, L. A.; Sidelnikov, Yu. V.; Koshelev, K. N.; Schulz, A.; Ralchenko, Yuri

doi:10.1002/(sici)1521-3986(200004)40:1/2<167::aid-ctpp167>3.0.co;2-w

Cited by 4 publications

(2 citation statements)

References 10 publications

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“…Specifically, charge exchange between multicharged impurity ions and hydrogen (or deuterium or tritium) atoms in tokamaks provides a nonlinear coupling of kinetics of impurities and neutrals, thus affecting the feasibility of controlled fusion (since multicharged ions produce considerably more radiative losses per unit particle than singly charged ions of the nuclear fuel components)-see, e.g., [1,2] and references therein. Second, charge exchange has been proposed as one of the most effective mechanisms for population inversion in the soft x-ray and VUV ranges [3][4][5][6]. In this scheme, an inversion is created by a selective quasiresonant population of excited ionic levels due to the interaction of a multicharged ionic beam with cold gaseous or low-charged plasma targets.…”

Section: Introductionmentioning

confidence: 99%

A purely classical description of crossings of energy levels and spectroscopic signatures of charge exchange

Oks¹

2000

J. Phys. B: At. Mol. Opt. Phys.

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Charge exchange and crossings of corresponding energy levels that enhance charge exchange are strongly connected with problems of energy loss and diagnostics in high-temperature plasmas. Charge exchange has also been proposed as one of the most effective mechanisms for population inversion in the soft x-ray and VUV ranges. One area of the most fundamental theoretical importance in the study of charge exchange is the problem of electron terms in the field of two stationary Coulomb centres (TCC) of charges Z and Z' separated by a distance R. This involves fascinating atomic physics: the terms can have crossings and quasicrossings. These rich features of the TCC problem are also manifest in other areas of physics such as plasma spectroscopy: a quasicrossing of the TCC terms, by enhancing charge exchange, can result in an unusual structure (a dip) in the spectral line profile emitted by a Z-ion from a plasma consisting of both Z- and Z'-ions, as has been shown theoretically and experimentally. The paradigm is that these sophisticated features of the TCC problem and their flourishing applications are inherently quantum phenomena. In this paper we disprove this paradigm. We present a purely classical description of both the crossings of energy levels in the TCC problem and the dips in the corresponding spectral line profiles caused by the crossing (via enhanced charge exchange). Our classical description is based on first principles and does not use any model assumptions.

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Section: Introductionmentioning

confidence: 99%

A purely classical description of crossings of energy levels and spectroscopic signatures of charge exchange

Oks¹

2000

J. Phys. B: At. Mol. Opt. Phys.

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“…Hot plasma containing highly ionized atoms flows out from 'necks' and may be subject to charge-exchange recombination via interaction with low ionized atoms of the main plasma column. Effects of stimulated emission in VUV due to the interaction of such hot plasma flow with the cold surrounding plasma were demonstrated for Z-pinch discharges and capillary discharges [5][6][7]. In capillary discharges lasing conditions were associated with 'self-organizing' neck instabilities [8].…”

Section: Introductionmentioning

confidence: 99%

Axially inhomogeneous plasma in fast discharges for creation of population inversion in soft x-ray region

Antsiferov¹,

Dorokhin²,

Koshelev³

et al. 2004

J. Phys. D: Appl. Phys.

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Self-organizing ‘neck’ type instabilities in capillary discharges are believed to be responsible for the population inversion in vacuum ultraviolet (VUV) spectral region. Selective population of the lasing levels originates as a result of charge–exchange recombination of the hot plasma ions during their flow from ‘necks’ into the cold surrounding gas. We propose a new approach of the ‘induced neck’ exploiting the axially inhomogeneous shock wave, generated in a capillary with a special wall profile and with high discharge current time derivative (about 1012 A s−1). A series of experiments with argon filling of the profiled capillary tube were performed. Time resolved pinhole VUV images of the discharge volume demonstrate the presence of the hot and compressed plasma objects on the discharge axes. All of them reproducibly appear at the same time and strictly on the axis of the capillary, in accordance with the wall structure. The VUV spectra, emitted by the compressed plasma, indicate a rather high electron temperature (50–100 eV), which must be sufficient for the production of hot plasma outflow.

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Electric field induced crossings of energy terms of a Rydberg quasi molecule enhancing charge exchange and ionization

Kryukov

Oks

2012

Can. J. Phys.

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Charge exchange is one of the most important atomic processes in plasmas. Charge exchange and crossings of corresponding energy levels that enhance charge exchange are strongly connected with problems of energy losses and of diagnostics in high temperature plasmas. Charge exchange was also proposed as an effective mechanism for population inversion in the soft X-ray and vacuum ultraviolet ranges. One of the most fundamental theoretical domains for studying charge exchange is the problem of electron terms in the field of two stationary Coulomb centers (TCC) of charges Z and Z′ separated by a distance R. It presents an intriguing atomic physics: the terms can have crossings and quasi crossings. These intrinsic features of the TCC problem also manifest in different areas of physics, such as plasma spectroscopy: a quasi crossing of the TCC terms, by enhancing charge exchange, can result in an unusual structure (a dip) in the spectral line profile emitted by a Z-ion from a plasma consisting of both Z-and Z′-ions, as was shown theoretically and experimentally. Before the year 2000, the paradigm was that the preceding sophisticated features of the TCC problem and its flourishing applications were inherently quantum phenomena. In 2000, a purely classical description of the crossings of energy terms was presented. In the present paper we study the effect of an electric field (along the internuclear axis) on circular Rydberg states of the TCC system. We provide analytical results for strong fields, as well as numerical results for moderate fields. We show that the electric field has several effects. First, it leads to the appearance of an extra energy term: the fourth classical energy term -in addition to the three classical energy terms at zero field. Second, but more importantly, the electric field creates additional crossings of these energy terms. We show that some of these crossings significantly enhance charge exchange, while other crossings enhance the ionization of the Rydberg quasi molecule. PACS Nos: 32.60.+i, 32.80.Ee, 34.70.+e, 33.80.Be, 31.15.-pRésumé : L'échange de charge est le plus important mécanisme atomique dans les plasmas. L'échange de charge et le croisement des niveaux d'énergie correspondants qui augmente l'échange de charge sont fortement connectés aux problèmes de perte d'énergie et de diagnostique dans les plasmas de haute température. L'échange de charge a aussi été proposé comme un mécanisme efficace pour l'inversion de population dans les domaines VUV et rayon-X mou. Le problème des termes de l'électron dans le champ de deux centres coulombiens stationnaires (TCC) de charges Z et Z′ séparés par une distance R, est central dans l'étude de l'échange de charge. C'est un problème intriguant en physique atomique : les termes peuvent avoir des croisements et des quasi croisements. Ces caractéristiques intrinsèques se manifestent également dans d'autres domaines de la physique, comme la spectroscopie du plasma : un quasi croisement des termes TCC, par augmentation de l'échange de charge, peut donner ...

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Inverse Populations of Multicharged Ion Levels in a Z-Pinch Plasma as a Result of Interaction of Plasma Beams with Neutral or Low-Ionized Gas Targets

Cited by 4 publications

References 10 publications

A purely classical description of crossings of energy levels and spectroscopic signatures of charge exchange

A purely classical description of crossings of energy levels and spectroscopic signatures of charge exchange

Axially inhomogeneous plasma in fast discharges for creation of population inversion in soft x-ray region

Electric field induced crossings of energy terms of a Rydberg quasi molecule enhancing charge exchange and ionization

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