The ANCHOR-SUNDYN endstation at the ALOISA beamline of the Elettra Synchrotron (Trieste, Italy) allows for performing a variety of “static” and time-resolved spectroscopies on organic films and interfaces.
The photon energy range of the beamline is 140-1200 eV, with a resolving power in the order of 2000-5000 in standard working conditions (0.5-1×10¹² photons/s). High-resolution X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure spectroscopy (NEXAFS) are typically employed for the chemical analysis of the samples. The chamber is also equipped with a monochromatic X-ray source (Omicron XM1000 MkII) and a helium discharge lamp (Omicron HIS 13) which are used for a complementary characterization of the systems and “offline” (i.e., without synchrotron radiation) measurements. Photoelectrons are detected via a 150 mm analyzer (SPECS, Phoibos 150); the electron detector is a 2D delay-line, specifically developed for time-resolved experiments.

A variable temperature (200–900 K) sample holder is mounted on a 5-axis manipulator (VG), and a load-lock system is also present for fast sample replacement. Both the chamber setup and the sample holder have been developed in-house. The system operates in ultra-high vacuum (UHV) conditions, with a typical base pressure of 2×10^-10 mbar. Sample growth is performed in situ via physical vapor deposition (PVD) either through effusion cells or Pyrex vials. The excitation source for time-resolved spectroscopies is a Yb:YAG fiber laser (Amplitude Systèmes, Tangerine HP), whose fundamental wavelength is 1030 nm (1.2 eV). Non-linear beta barium borate crystals are used for generating the higher harmonics up to the 5th (i.e., 515, 343, 257, and 206 nm). The laser can operate at repetition rates between 175 kHz and 2 MHz. In this range, it provides > 35 W of average power, consequently, the energy per pulse ranges from 200 μJ down to ∼18 μJ. The pulse duration can be varied from 310 fs up to 10 ps by tuning the pulse compressor. A large part of the laser output (26 W) is used to feed an optical parametric amplifier (Amplitude Systèmes, Mango OPA) which provides full photon energy tunability in the 210–2600 nm wavelength range. It has been configured for operation at 385 kHz. The OPA output can be used either for optical pump / X-ray probe experiments or for time-resolved two-photon photoemission (tr-2PPE) measurements, in which one of the discrete harmonics of the fundamental laser frequency is used as a probe.