SuperESCA beamline description

Page 1 of 7

Overview

SuperESCA has been the first beamline operating at Elettra since 1993. The beamline has been designed primarily for soft X-ray photoemission experiments on surfaces. In order to achieve high energy resolution keeping at the same time a high photon flux, the light produced by the insertion device is collected, monochromatized and brought to the experimental station following a prefoucusing-monochromator-refocusing scheme.

Beamline layout



The SuperESCA light source is a 2-section undulator which provides horizontally polarized photons. At 10 m from the source a pinhole selects the desired region of the undulator emission cone. Since the SuperESCA beamline shares the insertion device with ESCA Microscopy, a plane mirror is used to switch the light towards the operating beamline. The radiation is pre-focused into the monochromator entrance slit by a vertically oriented cylindrical mirror (2° angle of incidence). The dispersed light coming out from the monochromator exit slit is finally re-focused by an ellipsoidal mirror on the sample in the experimental chamber.

Insertion device

SuperESCA and ESCA Microscopy beamlines share a recently (December 2010)  installed insertion device: a linear planar undulator (LPU) from Kyma s.r.l.
The new insertion device is a 46-mm-period undulator with 98 periods and consists of two equal modules which produce horizontally polarised light. By setting the gap value from a minimum of 13.5 mm up to 40 mm the photon energy can be varied in the range 90÷1500 or 130÷1800 eV when the Elettra storage ring works at 2.0 or 2.4 GeV, respectively.
The possibility of tapering the undulator gap (up to 1 mm) allows a controlled enlargement of the harmonic spectrum at particular energies.
The insertion device is characterized by a maximum brilliance of 4.36x1018 ph/s/100 mA/0.1% BW/mm2/mrad2.

Last Updated on Friday, 31 March 2017 13:54