Experimental and theoretical analysis for total electron scattering cross sections of benzene.

Abstract

Measurements of the total electron scattering cross sections (TCSs) from benzene, in the impact energy range of 1-1000 eV, are presented here by combining two different experimental systems. The first utilizes a magnetically confined electron transmission beam for the lower energies (1-300 eV), while the second utilizes a linear transmission beam apparatus for the higher energies (100-1000 eV). These cross sections have also been calculated by means of two different theoretical methods, the Schwinger Multichannel with Pseudo Potential (SMCPP) procedure, employing two different approaches to account for the polarization of the target for impact energies between 0.1 and 15 eV, and the Independent Atom Model with the Screening Corrected Additivity Rule including Interference effect (IAM-SCAR+I) paradigm to cover the 10-10 000 eV impact energy range. The present results are compared with available theoretical and experimental data, with the level of accord being good in some cases and less satisfactory in others, and some predicted resonances have been identified. In particular, we found a π* shape resonance at 1.4 eV and another feature in the energy region 4.6-4.9 eV interpreted as a π* resonance (2B2g symmetry), which is a mixture of shape and a core excited resonance, as well as a Feshbach resonance at 5.87 eV associated with the 3s (a1g) Rydberg state. A Born-type formula to extrapolate TCS values for energies above 10 000 eV is also given. This study provides a complete set of TCS data, with uncertainty limits within 10%, ready to be used for modeling electron transport applications.