ALOISA Beamline

The experimental chamber hosts six emispherical electron energy analysers, one of them (66 mm mean radius) with ~2 degrees angular resolution and two angular degrees of freedom. Also two photon detectors are available working in counting mode for Grazing Incidence X-ray Diffraction (GIXD). The sample is mounted on a high resolution manipulator with six degrees of freedom. The preparation chamber offers four deposition cells in a liquid Nitrogen cooled flange (Knudsen cells and electron bombardment cells), a RHEED system, a sputter gun, a fast entry system for rapid change of the sample.

The combination of GIXD and photoelectron diffraction allows fast and reliable structural determination of in situ grown films. Moreover the growth can be monitored in real time by RHEED. The very wide range of geometrical configurations of the sample manipulator + detection system allows Photoelectron Diffraction measurements in near node geometry.

The possibility to perform resonant spectroscopies and Auger Photoelectron Coincidence Spectroscopy (APECS) is an efficient way of studying complex Auger lines. Angle resolved APECS is a unique feature of the beamline.

Experimental chamber instrumentation

    • 5 electron analysers (33 mm mean radius; resolution: 50 meV; acceptance angle 2°) for APECS.
    • 1 phosphorum plate with CCD camera for 2D reflectivity measurements and sample alignment
    • 1 electron analyzer (66 mm mean radius) equipped with a 2D-delay line detector for XPS and PED
    • 1 energy resolved photodiode for surface X-ray diffraction (SXRD)
    • 1 channeltron for partial yield measurements (XAS)
    • 2 total current photodiodes for in-plane X-ray diffraction and reflectivity
    • Sample transfer system with fast entry-lock;
    • RHEED apparatus;
    • MBE cryopanel with 4 slots for Knudsen and electron bombardment evaporators, 2 quartz microbalances, shutters;
    • ion gun;
    • gas line.
    • six degrees of freedom (0.004° accuracy for azimut and incidence angles)
    • main rotation arm coaxial to the photon beam for free orientation of the surface with respect to the photon polarization at constant grazing angle
    • temperature range 150-1100 K


rotating element rotation axis extension resolution
Experimental Chamber SR beam ±120° 0.00015°
Axial Frame SR beam ±120° 0.0002°
Bi-modal Frame perpendicular to the SR beam ±100° 0.0002°
Sample Holder SR beam -90˚; +185° 0.001°
Sample Holder grazing angle -2°; +15° 0.001°
Sample Holder surface normal ±95° 0.001°

Ultima modifica il Martedì, 07 Maggio 2013 10:33