Novel method for state selective determination of electron-impact-excitation cross sections from 0° to 180°

Weyland, M. and Ren, X. and Pflüger, T. and Baek, W. and Bartschat, K. and Zatsarinny, O. and Fursa, D. et al. 2014. Novel method for state selective determination of electron-impact-excitation cross sections from 0° to 180°. EPJ Techniques and Instrumentation. 1 (6): pp. 1-13.

Source Title

EPJ Techniques and Instrumentation

DOI

10.1140/epjti/s40485-014-0006-2

ISSN

2195-7045

School

Department of Physics and Astronomy

Remarks

This article is published under the Open Access publishing model and distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/2.0/ Please refer to the licence to obtain terms for any further reuse or distribution of this work.

URI

http://hdl.handle.net/20.500.11937/18390

Collection

Curtin Research Publications

Abstract

We use an improved target recoil momentum spectroscopy setup to determine differential cross sections for excited metastable state production in atoms and molecules by electron impact and show its capabilities for an atomic helium target. A crossed beam setup with a supersonic helium jet and a pulsed electron beam at energies close to the excitation threshold of 19.82 eV was used. Measuring the recoil momentum vector of the target instead of the momentum of the scattered electron removes common restrictions to the accessible scattering angles while the microchannel plate detector ensures a high counting efficiency. Using a photoemission electron source we reach an energy resolution of about 200 meV at 1 μA peak current. Results are compared with simulations using theoretical convergent-close-coupling (CCC), R-matrix with pseudo-states (RMPS) and B-spline R-matrix (BSR) calculations and show good agreement.