The ionization of Mg by electron impact at 1000 eV studied by (e, 2e) experiments

Abstract

The ionization of Mg 3s and 2p and He 1s has been studied in (e, 2e) experiments at about 1000 eV incident energy and 20 eV ejected electron energy for a momentum transfer between 0.5 and 2.1 au. The comparison with the predictions of the distorted wave Born approximation model shows a generally good agreement between experiment and theory. The differences observed between the He and Mg angular distributions can be explained as an initial state effect and are attributed to the differences between the He 1s and Mg 3s wavefunctions in the momentum space.

The Auger spectroscopy of pyrimidine and halogen-substituted pyrimidines

“…All the Auger spectra reported in this work have been measured for isolated molecular targets in the gas phase in electron impact experiments at 1 keV incident energy. The apparatus has been recently described in detail elsewhere, 7 and here, only information and settings relevant to the present measurements will be reported. The vacuum chamber contains an electron gun, two twin 180°hemispherical electrostatic analyzers of mean radius of 60 mm, independently rotatable, and a source for the gaseous target.…”

“…By contrast, 5-bromopyrimidine and 2-chloropyrimidine are powders at room temperature with an expected vapor pressure about two orders of magnitude smaller than pyrimidine. 8 So we placed the powders directly into the crucible of a resistively heated oven 7 hosted in the experimental chamber. The oven is composed by a stainless steel crucible with a 10 mm long and 1 mm wide output nozzle and a heater enclosed in a copper water cooled jacket.…”

Calculation of (e, 2e) triple differential cross sections of Mg in coplanar geometry

“…The solid circles are experimental data of Murray [28]. Till date there are few attempts, as mentioned in the introduction section of this paper, to explain the features of TDCS of doubly symmetric (e, 2e) processes [22,34] and unequal energy sharing condition [35,36] on Mg (3s) target. All of these calculations have been done in DWBA formalism and have mix degree of agreement with the experimental results.…”

“…Following the experimental results of Murray [28] several theoretical results have been reported for the (e, 2e) processes in coplanar geometry on the alkali and alkali earth targets [22,[29][30][31][32][33][34] and particularly, the study of (e, 2e) processes on Ca atom [22,29,32,33]. Apart from the above mentioned studies Bolognesi et al [35,36] have reported a series of (e, 2e) measurements in unequal energy sharing conditions for the ionization of Mg (3s) target. Most of these studies have been performed in DWBA formalism and the first CCC calculation has been reported for the electron-sodium ionization in coplanar symmetric geometry [31].…”

(e,2e) experiments on C60

“…Only one previous investigation by electron impact of a thin solid film of C 60 by the (e,2e) technique has been reported [2]. The present gas phase experiments have been performed with the (e,2e) spectrometer of CNR-IMIP in Rome, which has been recently equipped with an oven [3]. Here we have studied the ionization of C 60 molecules in an effusive beam by about 1000 and 500 eV electrons: the experiments have been done in asymmetric kinematics and the experimental conditions were varied in order to investigate the ionization dynamics and to attempt a reconstruction of the electronic structure.…”