Showing papers by "Anindya Sarkar published in 2008"
TL;DR: In this article, the first measurements of total cross sections for positron scattering from the important bio-molecule 3-hydroxy-tetrahydrofuran were reported.
Abstract: We report on the first measurements of total cross sections for positron scattering from the important bio-molecule 3-hydroxy-tetrahydrofuran In this case the energy range of our work is 04–184 eV While there are currently no theoretical data against which we can compare these results, a comparison with corresponding measurements for the geometrically similar species tetrahydrofuran is made This comparison enables us to infer information on the role that the conformers of 3-hydroxy-tetrahydrofuran play in the scattering process
27 citations
TL;DR: In this article, the authors report on measurements of total cross sections for positron scattering from the fundamental molecule formic acid (HCOOH) in the energy range of their experimental work is $0.3 -50.2
Abstract: We report on measurements of total cross sections for positron scattering from the fundamental molecule formic acid (HCOOH). In this case, the energy range of our experimental work is $0.3--50.2\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$. Our interpretation of these data was somewhat complicated by the fact that at room temperature, formic acid vapor consists of about 95% monomer and 5% dimer forms, so that the present cross sections represent an average for that ensemble. To assist us in interpreting the data, rigorous Schwinger multichannel level calculations for positron elastic scattering from the formic acid monomer were also undertaken. These calculations, incorporating an accurate model for the target polarization, are found to be in good qualitative agreement with our measured data, particularly when allowance is made for the target beam mixture (monomer versus dimer) in the experiment.
21 citations
TL;DR: In this article, the authors report total cross sections for positron scattering from two primary alcohols, methanol and ethanol, and compare their data to the only previous result from Kimura and colleagues, with a significant discrepancy between them being found at the lower energies.
Abstract: We report total cross sections for positron scattering from two primary alcohols, methanol $(\mathrm{C}{\mathrm{H}}_{3}\mathrm{O}\mathrm{H})$ and ethanol $({\mathrm{C}}_{2}{\mathrm{H}}_{5}\mathrm{O}\mathrm{H})$. The energy range of the present study is $0.1--40\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$. The ethanol measurement appears to be original while for methanol we compare our data to the only previous result from Kimura and colleagues [Adv. Chem. Phys. 111, 537 (2000)], with a significant discrepancy between them being found at the lower energies. Positronium formation threshold energies for both species, deduced from the present respective total cross section data sets, are found to be consistent with those expected on the basis of their known ionization energies. There are currently no theoretical results against which we can compare our total cross sections.
9 citations