XXIX conference on plasma physics and CF, February 25 – March 1, 2002, Zvenigorod
UNIVERSAL METHOD OF CALCULATION OF MULTICHARGED IONS STATES
POPULATIONS IN PLASMA.
Bureeva L.A., *Lisitsa V.S., **Petrov D.A.
Institute of Spectroscopy of the RAS, Moscow, Russia, e-mail: bureyeva@sci.lebedev.ru
*
NFI RRC «Kurchatovskiy institute», Moscow, Russia, e-mail: lisitsa@nfi.kiae.ru
**
MEPhI, Moscow, Russia, e-mail: dmitriy.petrov@transtk.ru
Now rather urgent the tasks of diagnostics of plasma in a tokamak are. The special interest is
represented by a task of calculation of ions states populations in plasmas. The goal of this work is
creation of a method and development of a fast numerical code for calculation of energy level
populations.
The exact formal populations calculation can be carried out by using a return matrix of system of
the equations for populations (in a case of noncollisional plasma - Seaton cascade matrix), in which
elements all elementary processes influencing on kinetic are taken into account. However in
practice such account is rather bulky, as every time should be solved new system of the equations
and, in view of the greater number of levels, the quantity of the equations in system grows, as n2.
With the account for what has been said above in frameworks of quasi-stationar model the
method of atomic excited level population calculation in plasmas synthesizing account of the
bottom energy levels by using a return matrix of system of equations for populations with analytical
high excited state population calculations on the basis of the Beigman theory was created.
In a basis of a method connection of the decision by using a return matrix of system of the
equations for populations (for the bottom area of a spectrum) and decision integrodifferrential
equation, which nucleus is the Green function (for the top area of a spectrum) is fixed.
Advantage of a method described in the given work, is that it allows rather quickly to calculate
of nonhydrogen ions exited level populations in a rather wide range of a charge Z. Thus all basic
processes proceeding in plasma at considered conditions are taken into account. One more feature
of the offered method consists that it works in a spectrum of temperature and density from coronal
limit up to thermodynamic balance, when populations are allocated by Boltsman distribution
function. Such wide area of applicability is achieved by introduction of additional boundary
conditions on Green function in the top area of a spectrum, and account of detailed balance between
mutually return processes in bottom.
The numerical code for populations calculation by using the given method is developed.
References.
[1] Vanstein L.A., Sobelman I.I., Jukov E.A. “Excitation of atoms and broadening of spectral
line ” , Springer, 1981.
[2] D.E. Post, R.V. Jensen, C.B. Tarter, W.H. Grasberger, W.A. Lokke: Steady-State Radiative
Cooling Rates For Low-Density High-Temperature Plasmas, Atomic Data and Data Tables,
vol. 20, № 5, 1977.
[3] Beigman I.L., Proc. Of the Lebedev Physical Institute, 179 , p. 160 (1987).
[4] L.A. Bureyeva, V.S. Lisitsa: A Perturbed Atom (Gordon and Beach 2000).
Authors
Bureeva L.A., Institute of Spectroscopy of the RAS, Moscow, Russia,
e-mail: bureyeva@sci.lebedev.ru
Lisitsa V.S., NFI RRC “Kurchatov Institute”, Moscow, Russia, e-mail: lisitsa@nfi.kiae.su
Shuvaev D.A., MEPhI, Moscow, Russia, e-mail: dshuvaev@mail.ru