Near-threshold electron-impact excitation of argon studied with the time-of-flight technique
1 Centre for Antimatter-Matter Studies, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200, Australia
2 Instituto de Fisica Fundamental, CSIC, Serrano 113-bis, 28006, Madrid, Spain
3 Department of Physics and Astronomy, Drake University, Des Moines, IA, USA
PMC Physics B 2009, 2:3 doi:10.1186/1754-0429-2-3Published: 18 December 2009
Absolute angle-differential cross-section data are presented for excitation of the 3p54s manifold in argon by electron impact. The investigation focuses on the near-threshold region, where previous studies have revealed persistent disparities between measurements and theoretical predictions. For the present experiment, the time-of-flight (TOF) technique is employed. This method allows for scattered electrons to be measured over a broad range of energies with a constant transmission, thereby eliminating a potential major source of error in relating relative intensities of elastic and inelastic transitions inherent to other experimental techniques. The present experimental data are compared to theoretical results obtained in relativistic distorted-wave and various R-matrix (close-coupling) approaches, as well as to other recently published experimental data.
PACS Codes: 34.80.Dp