We utilize the analytic atomic independent-particle model (IPM) of Green, Sellin, and Zachor as a basis for calculating generalized oscillator strengths for the single-particle excitations of Ne, Ar, Kr, and Xe. First, we establish averages of the experimental energy levels to arrive at single-particle states. We then adjust the two parameters so that the IPM potentials accurately characterize these excited-state energies. Using the wave functions associated with these potentials and the Born approximation, we calculate the generalized oscillator strengths for excitations to p ns states. A very complex nodal structure is apparent at large values of momentum transfer and a rapid decline in magnitude occurs after the second node. We may accurately characterize the results up to the second node with a convenient analytic form which leads to analytic total excitation cross sections. We use available optical oscillator strengths to normalize our results. The systematics and regularities of the parameters for various Rydberg series are discussed and approximate scaling laws are given.

The Space Research Coordination Center, established in May, 1963. has the following functions: (1) it administers predoctoral and postdoctoral fellowships in space-related science and engineering programs; (2) it makes available, on application and after review, allocations to assist new faculty members in the Division of the Natural Sciences and the School of Engineering to initiate research programs or to permit established faculty members to do preliminary; work on research ideas of a novel character; (3) in the Division of the Natural Sciences it makes an annual allocation of funds to the interdisciplinary Laboratory for Atmospheric and Space Sciences; (4) in die School of Engineering it makes a similar allocation of funds to the Department of Metallurgical and Materials Engineering and to the program in Engineering Systems Management of the Department of Industrial Engineering; and (5) in concert with the University's Knowledge Availability Systems Center, it seeks to assist in the orderly transfer of new space-generated knowledge in industrial application. The Center also Issues periodic reports of space-oriented research and a comprehensive annual report. Abstract Absolute cross sections have been measured for the excitation of

We utilize the analytic atomic independent-particle model (IPM) of Green, Sellin, and Zachor to calculate generalized oscillator strengths (GOS) and total cross sections for excitation and ionization of atomic oxygen. First we average over the experimental energy levels within a multiplet to arrive at single-particle levels. Then we adjust the two parameters of the IPM potential so that it accurately characterizes the ground state and 15 lowest excited states. Using the wave functions so obtained, and assuming the Born approximation and the I S-coupling scheme, we calculate absolute GOS and cross sections for excitation to these levels, and for ionization with incident energies up to 1000 eV and secondary electron energy up to 200 eV. We obtain an analytic representation of the excitation GOS as a function of the momentum transfer. We also obtain an analytic representation of the energy differential cross section for ionization as a function of the energies of the incident and secondary electrons. Comparison is made with available experimental data and other calculations.

The L &0 phase shifts 5z for low-energy scattering by a van der Waals~potential are calculated using the two-potential formula of scattering theory. We calculate tang& up to and including the k~" ink term. We compare our results with those obtained using the Born approximation.

Abstract. Oscillator strengths for excitations of As i, As ii, and As iii from their ground states to various excited states are calculated using a semiempirical analytic independent-particle-model. The results are compared to experimental and theoretical data where possible. The results are of astrophysical interest.