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Manuscript Title: The multichannel eikonal theory program for electron-atom scattering.
Authors: E.J. Mansky, M.R. Flannery
Program title: MET_states
Catalogue identifier: ADAY_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 88(1995)249
Programming language: Fortran.
Computer: IBM RS/6000 model 520.
Operating system: AIX 3.1.7, HP-UX 8.07, 9.01.
RAM: 2K words
Word size: 32
Peripherals: disc.
Keywords: Atomic physics, Scattering, Electron, State multipoles, Orientation, Alignment tensor, Scattering amplitude, Substate magnetic Coherences, Stokes parameters.
Classification: 2.4.

Subprograms used:
Cat Id Title Reference
ADAW_v1_0 MET_cross CPC 88(1995)249

Nature of problem:
Given the complex scattering amplitudes fi->n(theta) for excitation of atomic states |n>, by intermediate to high energy electrons, calculate the state multipoles <T(J'J)KQ+> characterizing the coherence among the magnetic substates and the correlation between the scattered electron and the photon emitted in the decay of the state |n> under the influence of the Q-component of a tensor T of rank K. Also, completely determine the degree of polarization of the emitted radiation by computing the Stokes parameters Pi and density matrices rhoin.

Solution method:
At present the program applies the formulae of Fano and Macek [1,2] for the orientation vector O and alignment tensor A , the state Q+- Q+- multipoles of Blum and Kleinpoppen [3] and the Stokes parameters Pi of Andersen and co-workers [4-6], to the complex scattering amplitudes fi->n(theta) generated by the multichannel eikonal theory code.

Restrictions:
The program is presently limited to using the semiclassical scattering amplitudes obtained from the companion program in the spin-averaged versions of the formulae for the above physical observables in [1-6]. Future versions of the code will: (a) incorporate the use of the full, spin-dependent formulae for the state multipoles, coherence and correlation parameters and the Stokes parameters, and (b) allow the user to input complex scattering amplitudes obtained from other theories (e.g. R-matrix, distorted-wave).

Running time:
less than 30 seconds

References:
[1] U. Fano and J.H. Macek, Rev. Mod. Phys. 45(1973)553.
[2] J.H. Macek and D.H. Jaecks, Phys. Rev. A 4(1971)2288.
[3] K. Blum and H. Kleinpoppen, J. Phys. B: At. Mol. Phys. 10(1977)3283, Phys. Rep. 52(1979)203.
[4] N. Andersen and S.E. Nielsen, Adv. At. Mol. Phys. 18(1982)265.
[5] H.W. Hermann and I.V. Hertel, Comments At. Mol. Phys. 12(1982)61,127
[6] N. Andersen, J.W. Gallagher and I.V. Hertel, Phys. Rep. 165(1988)1.