Two-Photon Raman scattering and high excitation luminescence in ZnTe

Two-Photon-Raman Scattering (TPRS) and the luminescence of ZnTe are investigated when the samples are highly excited with a tunable narrow-band dye-laser. In luminescence, one observes emission bands due to the well-known inelastic exciton-exciton scattering at intermediate excitation intensities, and the recombination radiation of an electronhole plasma (EHP) at the highest excitation levels. For the first time, TPRS is reported in ZnTe. From the change in the TPRS lines in magnetic fields up to 10T we deduce a diamagnetic shift of 1.2°10^?2 meV/T² of the free longitudinal exciton. This value is in good agreement with results obtained by other authors from reflection spectroscopy.     

Conductivity in an activity gradient

A procedure to evaluate conductivity measurements on a sample exposed to an activity gradient is presented The method allows the measured mean conductivity to be subsequently associated with a denned activity It offers not only an experimentally simple alternative to the Wagner-Hebb experiment, but also enables detailed information to be obtained about the activity dependence of the conductivity in polarization measurements with two blocking electrodes as well as in concentration cell experiments, no matter whether a two- or four-point arrangement is used It is further shown how the steady-state activities, which are necessary to compute the desired mean value, can be obtained from the initial and boundary conditions     

Excitation functions of the analyzing power in elastic proton-proton scattering from 0.45 to 2.5 GeV

Excitation functions A_N(p_lab,_c.m.) of the analyzing power in elastic proton-proton scattering have been measured in an internal target experiment at the Cooler Synchrotron COSY with an unpolarized proton beam and a polarized atomic hydrogen target. Data were taken continuously during the acceleration and deceleration for proton kinetic energies T_lab (momenta p_lab) between 0.45 and 2.5 GeV (1.0 and 3.3 GeV/c) and scattering angles 30 ^° _c.m. 90^°. The results provide excitation functions and angular distributions of high precision and internal consistency. The data can be used as calibration standard between 0.45 and 2.5 GeV. They have significant impact on phase shift solutions, in particular on the spin triplet phase shifts between 1.0 and 1.8 GeV.