ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
This paper describes the realization of a new electrostatic electron spectrometer, called MAPDESS, for the parallel measurement of angular distributions in gas-phase electron scattering experiments. The electron beam originates from a filament and a standard 127° cylindrical monochromator, and the beam is carried to the collision center at the desired energy by three successive cylindrical electron lenses that partly compensate for the high dissymmetry of the beam. The electrons scattered off the gaseous target are filtered by a 19-aperture angle selector (from 18° to 162°) and injected into the energy analyzer by means of an annular zoom lens. This lens allows one to keep control of the beam in the retarding or accelerating process, which is necessary to get a good resolution and/or intensity. The analyzer is a novel truncated spherical mirror symmetric about the scattering center and whose ring-shaped exit is coupled to 19 channel electron multipliers, thereby allowing parallel multiangle detection. This spectrometer thus directly gives the angular distribution of an energy-resolved scattering event in a plane. The angular resolution is shown to be ±3°. Some measurements in rare gases are presented, showing an energy resolution of 25 meV at a pass energy of 7 eV.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1140339
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