High resolution (e,2e) measurements using a new toroidal spectrometer

Abstract

A new electron coincidence spectrometer based around toroidal sector electrodes is described, whose design has been optimised for electron impact induced (e,2e) ionization studies. An improvement in data collection efficiency of more than three orders of magnitude compared to its predecessor has been achieved. The strengths and weaknesses of the design are assessed by comparison with other technologies employed for the coincidence detection of reaction products. Preliminary results for the simultaneous ionization plus excitation of helium leading to the He+ n=2 and n=3 states are presented, demonstrating the sensitivity of the new device. Show more