Choice of gauge in 2photon 1s2s transition in atomic hydrogen and pseudostate expansions
Abstract
The problem of gauge choice in multiphoton transitions in connection with the proper choice of the unperturbed wave functions require to insure gauge invariance was considered. J. Bassani, J. J. Forney, and A. Quattropani considered the case of 2photon 1s2s transition rate for hydrogen, using gauges vector E x vector r and vector A x vector p. Exactly the same results were obtained for the two gauges, but the findings indicate that the vector E x vector r interaction tends to the final result with a small number of intermediate states and is therefore the one to be used in any approximate calculation. Whether the socalled pseudostate expansion method works equally well with either gauge was tested. To accomplish this task, in addition to researching the problem, the FORTRAN programming was learned and a FORTRAN program was constructed for the calculation of the dimensionless 2photon transition probability amplitude D(v) for 1s2s transition in Hydrogen as a function as a function of the incident photon frequency v in gauge vector E x vector p at certain values of v, using the pseudostate method. However, some puzzling unresolved difficulties were experienced in the calculation. Then should the pseudostate calculations prove successful for gauge vector E x vector r the method will be applied to gauge vector A x vector p. If successful, then the problem is complete.
 Publication:

1989 NASAASEE Summer Faculty Fellowship Program in Aeronautics and Research
 Pub Date:
 September 1989
 Bibcode:
 1989asee.nasa...25S
 Keywords:

 Applications Programs (Computers);
 Computer Programming;
 Dimensionless Numbers;
 Fortran;
 Hydrogen;
 Photons;
 Wave Functions;
 Gauge Invariance;
 Measuring Instruments;
 Atomic and Molecular Physics