Beamline Description

The interconnected set of UHV chambers includes state-of-the-art surface preparation and survey (Ar ion sputtering, annealing, controlled evaporation, LEED/Auger characterization), atomic resolution scanning tunneling microscope (STM), and two beamlines delivering monochromatic synchrotron radiation to a high-energy/angle resolution spectrometer (ARPES-dedicated Scienta SES2002; total energy resolution (analyzer, temperature, photons) ~6meV, angular resolution ~0.2°) and to a complementary spectrometer allowing for soft-X-ray absorption (XAS) and magnetic dichroism (XMCD, XMLD), X-ray photoelectron spectroscopy (XPS) and spin polarization mapping. Samples can be loaded into the APE system via two differentially pumped load-locks and then transferred in UHV to any of the preparation chambers, to STM and to both synchrotron radiation spectrometers.
APE is designed to host independent experiments simultaneously on the two end stations. Photons with chosen polarization are emitted by two non-collinear Apple II type insertion devices and delivered in two distinct beamlines (please see beamline description), covering low 10-100eV photon energy range (APE-LE, dedicated to high resolution ARPES) and high 250-1500 eV photon energy range (APE-HE, dedicated to XAS, XMCD, XMLD, XPS). Both end stations are equipped with cryostats (minimum sample temperature during the measurements is 16 K (30 K) at APE-LE (APE-HE)).
APE also allows the integration of users' specialized sample growth chambers, which may be connected to the main sample distribution chamber and have full access to the off-beam and on-beam facilities. Long term users' programs are therefore possible, having access to beamtime based on usual assignment procedures, but having semi-permanent growth facilities and access to the off-beam diagnostics.

APE beamlines and APE laboratory are illustrated in the figures below. For detailed description, please see: Rev. Sci. Instrum. 80, 043105 (2009); doi:10.1063/1.3119364.