Calculation of spatial distribution of optical escape factor and its application to He I collisional-radiative model

Iida, Yohei; Kado, Shinichiro; Tanaka, Satoru
December 2010
Physics of Plasmas;Dec2010, Vol. 17 Issue 12, p123301
Academic Journal
An integral analytical formula for a spatial distribution of the optical escape factor (OEF) in an infinite cylindrical plasma is derived as a function of an arbitrary upper state spatial density profile, the temperature ratio of the upper state to the lower state, and the optical depth of the corresponding transition. Test calculations are carried out for three different upper state profiles, i.e., uniform (rectangular), parabolic, and Gaussian upper state profiles. The OEF takes on negative values at the periphery of the parabolic and Gaussian upper state profiles. These characteristics cannot be expressed by the conventional OEF formulas derived for the center of the plasma, even though the optical depth is increased. In addition to the analytical derivation of the formula, two practical formulas are proposed: an empirical formula of the spatial distribution of the OEF for the Gaussian upper state density profile and a linear formula of the OEF distribution for upper state profiles that are expressed as linear combinations. These formulas enable us to calculate the spatial distribution of the OEF for the multiple-Gaussian upper state profile without the need for time-consuming integral calculations.


Related Articles

  • Expansion rate measurements at moderate pressure of non-neutral electron plasmas in the Electron Diffusion Gauge (EDG) experiment. Morrison, Kyle A.; Davidson, Ronald C.; Paul, Stephen F.; Belli, Emily A.; Chao, Edward H. // Physics of Plasmas;Jul2001, Vol. 8 Issue 7, p3506 

    Measurements of the expansion rate of pure-electron plasmas have been performed on the Electron Diffusion Gauge (EDG) device at background helium gas pressures in the 5x10[sup -8] Torr to 2x10[sup -5] Torr range, where plasma expansion due to electron-neutral collisions dominates over plasma...

  • Rayleigh scattering and redistribution of radiation in Helium in a magnetic multipole plasma source. Drepper, P.; Maurmann, S.; Ferri, S.; Kunze, H.-J. // AIP Conference Proceedings;2001, Vol. 559 Issue 1, p172 

    Rayleigh scattering and redistribution of radiation in helium is investigated in a magnetic multipole plasma source. This yields information on how collisions affect near-resonant scattering. Electron temperatures in the range of 0.3 eV ≤ kTe ≤ 5 eV and electron densities in the...

  • Linear Polarisation Degree of He-Like Resonance Line Emitted from Aluminium Non-Thermal Laser-Produced Plasma. Bedrane, Z.; Inal, M. K. // International Review of Physics;Dec2010, Vol. 4 Issue 6, p327 

    The first Plasma Polarisation Spectroscopy experiment on laser-produced plasmas has been reported by Kieffer et al., the curios point in this experiment that the authors found no agreement between theory and experience, and the reason of the discrepancy was not known. T. Fujimoto and S....

  • Fluid and drift-kinetic description of a magnetized plasma with low collisionality and slow dynamics orderings. I. Electron theory. Ramos, J. J. // Physics of Plasmas;Aug2010, Vol. 17 Issue 8, p082502 

    A closed theoretical model to describe slow, macroscopic plasma processes in a fusion-relevant collisionality regime is set forward. This formulation is a hybrid one, with fluid conservation equations for particle number, momentum and energy, and drift-kinetic closures. Intended for realistic...

  • Kinetic linear model of the interaction of helical magnetic perturbations with cylindrical plasmas. Ivanov, Ivan B.; Heyn, Martin F.; Kasilov, Sergei V.; Kernbichler, Winfried // Physics of Plasmas;Feb2011, Vol. 18 Issue 2, p022501 

    The linear kinetic model of the interaction of helical rotating magnetic perturbations (resonant and nonresonant) with a tokamak plasma developed in [M. F. Heyn et al., Nucl. Fusion 46, S159 (2006)] is extended by a Galilean invariant collision operator and a different finite Larmor radius...

  • Bohm's criterion in a collisional magnetized plasma with thermal ions. Hatami, M. M.; Shokri, B. // Physics of Plasmas;Aug2012, Vol. 19 Issue 8, p083510 

    Using the hydrodynamic model and considering a planar geometry, the modified Bohm's sheath criterion is investigated in a magnetized, collisional plasma consisting of electron and positive ions with finite temperature. It is assumed that the singly charged positive ions enter into the sheath...

  • Plasma Polarization Spectroscopy: A+M Data Aspects. Fujimoto, Takashi; Iwamae, Atsushi // AIP Conference Proceedings;2005, Vol. 771 Issue 1, p33 

    Plasma Polarization Spectroscopy (PPS) has been applied to a helium plasma produced by ECR heating in a cusp-configuration magnetic field. Several neutral helium lines are found linearly polarized. The directions of polarization are perpendicular to the magnetic fields, and the polarization...

  • Line shape modeling by current semi-classical approaches. Buldyreva, Jeanna // AIP Conference Proceedings;10/29/2010, Vol. 1290 Issue 1, p119 

    After a short reminder of main line profile models currently used for extracting the collisional parameters from experimentally observed line shapes, some new aspects and applications of semi-classical theories of collisional line broadening and shifting of molecular gases are reviewed. A...

  • Non-perturbative probe laser-induced fluorescence spectroscopy of laser-cooled Ca-plasma in a linear radiofrequency ion trap. Aramaki, M.; Kameyama, S.; Kono, A. // AIP Conference Proceedings;Mar2013, Vol. 1521 Issue 1, p184 

    A non-perturbative probe laser induced fluorescence (LIF) system has been developed to observe a laser-cooled one-component plasma. Since the undistorted spectra can be obtained using this measurement system, a quantitative evaluation of the spectrum shape of the laser-cooled plasma was...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics