FineEstBeAMS beamline is equipped with the following attributes:
|Techniques||X-ray Photoelectron Spectroscopy (XPS), X-ray Absorption Spectroscopy (XAS), Photoelectron Photoion Coincidence Spectroscopy (PEPICO), Time-of Flight Mass Spectroscopy (TOF), Photoluminescence Spectroscopy (PS)|
|Beam Size||0.2 (V) x 0.2 (H) mm, best: 0.05 (V) x 0.05 (H) mm|
|Energy Range||4.5 - 1300 eV (275 - 0.95 nm)|
|Time Scales||nanoseconds to seconds|
|Samples||Atomis, Molecules, Clusters, Gases, Liquids, Atmospheric particles, Nanoparticles, Solids, Surfaces and Interfaces|
The radiation source is an elliptically polarizing undulator. It can provide radiation with different polarization properties: linearly polarized (horizontal, vertical, or inclined direction) and circularly polarized. Only linear horizontal and vertical polarizations have been tested extensively.
The photon energy range extends from 4.5 eV to about 1300 eV and is covered by two gratings. A 92 lines/mm grating (G2) can be used from 4.5 eV to 50 eV, while a 600 lines/mm grating works above 15 eV. However, the photon flux decreases considerably toward high photon energies. The actually usable photon energy range depends on the nature of particular experiments.
The beamline has achieved a resolving power of about 11000 at 400 eV photon energy using the exit slit of ~10 um in the monochromator.
A more detailed description of the beamline performance can be found in the Beamline optics page
Capabilities available for users
The GPES has been designed to detect coincidences between energy resolved electrons and positive ions (PEPICO), but single electron and ion time-of-flight spectra can, of course, be measured. A setup consisting of two ion TOF spectrometers is also available. It can be used to measure coincidences between negative ions and positive ions.
The PLES can be used to measure fluorescence emission from different kinds of solids in the infra-red, visible and ultraviolet spectral ranges. The excitation functions of these emissions can be determined by scanning the incident photon energy.
The SSES is now available to regular users for studies of atomic and electronic structure of bulk and surface materials. It has been designed as a high-throughput workhorse for XPS, ARPES, and XAS with flexible sample preparation options. The temperature of sample preparation can be around 100 K by liquid-nitrogen cooling and up to around 1300K by resistive heating, direct heating and e-beam heating. The temperature of sample during measurement can be around 100 K by liquid-nitrogen cooling, room temperature and up to 600 K by resistive heating.
Further information about the end stations can be found under submenu “Experimental stations”.
Single-bunch operation can be offered on certain beamline commissioning days (Tuesdays). If you would like to add a single-bunch day to your regular beamtime proposal, you should check this option as a detector under the selection of the end station (available for the PLES and GPES) and explain in your beamtime proposal why single-bunch operation is needed.
In addition, there will be a whole week of single-bunch operation in the period February 2023 – July 2023 . If you want to apply for a beamtime with single-bunch operation only, you should indicate it clearly in your beamtime proposal. Please note that the FinEstBeAMS beamline has no chopper.
Fast Access proposals
Starting from the Spring 2023 call, FinEstBeAMS opens up a new kind of proposals – Fast Access proposals – to allow very short experiments or feasibility tests to be done on a short notice. The access mode is only available for the SSES. Maximum 6 shifts (24 hrs) can be allocated for a single proposal. A fast-access proposal can only be scheduled in a pre-defined time. Please contact beamline personnel for the current schedule.
In the Spring 2023 call, FinEstBeAMS invites proposals from commissioning experts to commission further a recently developed aerodynamic lens sample delivery system. One week (30 shifts) of beamtime will be reserved for this purpose at the GPES, where the sample delivery system can be mounted in the horizontal direction while the electron spectrometer is positioned in the vertical direction. There are restrictions as for what kind of samples can be studied presently. For further information, please see the low density matter web page