Total cross sections for positron scattering on argon and krypton at intermediate and high energies
نویسندگان
چکیده
Preliminary total cross section data for positron scattering on argon and krypton between 250 and 5000 eV are presented. A Ramsauer-type apparatus, previously used for electron-scattering measurements has been modified. To check for the convergence between electron and positron total cross sections, a semiempirical analysis has been applied. The analysis for argon indicates an asymptotic convergence for electron and positron projectiles – the high energy parameters of the both fits are equal within the uncertainty limits. No such a clear conclusion is possible with the present data up to 5000 eV for krypton. 2002 Elsevier Science B.V. All rights reserved. PACS: 41.75.Fr; 34.80.Bm
منابع مشابه
Low-energy positron scattering from atoms and molecules using positron accumulation techniques
Positron scattering from atoms and molecules is studied at low values of incident positron energy. The experiments use a cold magnetized positron beam formed in a positron accumulator. A discussion of positron scattering in a magnetic ®eld is presented along with dierential cross-sections (DCS) for positron±atom collisions and positron± molecule total vibrational excitation cross-sections. Abs...
متن کاملLow Energy Cross-Sections for Positron Interactions with Cyclic Hydrocarbons
We report total cross-section measurements for positron scattering on cyclic hydrocarbons: benzene, aniline, and cyclohexane. Measurements were done by an absolute transition method in the energy range 1.5–20 eV (0.4–20 eV for cyclohexane). High cross-sections for all measured molecules were observed at low energies. In the case of cyclohexane the cross-section in the zero energy limit tends to...
متن کاملIonization and positronium formation in noble gases
Absolute measurements are presented for the positron-impact cross sections for direct ionization and positronium formation of noble gas atoms in the range of energies from threshold to 90 eV. The experiment uses a cold, trap-based positron beam and the technique of studying positron scattering in a strong magnetic field. The current data show generally good, quantitative agreement with previous...
متن کاملروش جفتشدگی نزدیک دومرکزی در فرآیند انتقال بار
In the present work, the transition matrix elements as well as differential and total scattering cross-sections for positronium formation in Positron-Hydrogen atom collision and hydrogen formation in Positronium-Hydrogen ion collision, through the charge transfer channel by Two-Centre Close-Coupling method up to a first order approximation have been calculated. The charge transfer collision is ...
متن کاملCalculation of the triple and double cross sections in the proton-hydrogen impact at the ionization channel by removing singularity in the scattering amplitudes
In the present work, the triple and double cross sections of atomic hydrogen ionization in collision with the proton are calculated. The potential of the interaction is considered as a Coulombic; also, the first and second order Born approximations have been used. The singularity of the Green operator in the second order approximation has been removed for the analytical solution of the scatt...
متن کامل