FineEstBeAMS beamline is equipped with the following attributes:

TechniquesX-ray Photoelectron Spectroscopy (XPS), X-ray Absorption Spectroscopy (XAS), Angle-resolved Photoemission Spectroscopy (ARPES), Photoelectron Photoion Coincidence Spectroscopy (PEPICO), Time-of Flight Mass Spectroscopy (TOF), Photoluminescence Spectroscopy (PS)
Beam Size0.2 (V) x 0.2 (H) mm, best: 0.05 (V) x 0.05 (H) mm
Energy Range4.5 - 1300 eV (275 - 0.95 nm)
Time Scalesnanoseconds to seconds
SamplesAtomis, 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 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.

Continuous scanning measurements, which move synchronously the photon energy and the undulator gap, work across an extended photon energy range above 180 eV photon energy and across short energy ranges also at lower photon energies.

A more detailed description of the beamline performance can be found in the Beamline optics page

Capabilities available for users

FinEstBeAMS has three operational end stations: Gas-phase end station (GPES), Photoluminescence end station (PLES), and Solid-state end station (SSES).

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. A magnetic bottle electron spectrometer can be requested for experiments in single-bunch operation but its use requires collaboration with the NANOMO research group from the University of Oulu (Finland).

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 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 95 K by liquid-nitrogen cooling and up to around 1300 K by resistive heating, direct heating and e-beam heating. The temperature of sample during measurement can be around 95 K by liquid-nitrogen cooling and 55 K by liquid-helium cooling, and from room temperature to to 600 K by resistive heating. In summer 2024, the SPECS electron analyzer of the SSES will be sent to the company for the exchange of the entrance slits. The analyzer is expected to come back in October 2024, and after that it will be commissioned before its return to user operation. Therefore, FinEstBeAMS will accept fewer proposals to the SSES than in the previous calls. Note that no XPS and ARPES experiments will be scheduled at the SSES in the first half of the Fall 2024 semester (preliminarily from August to mid-November).

Further information about the end stations can be found under submenu “Experimental stations”.

Single-bunch operation

There will be a whole week of single-bunch (SB) operation in the period September 2024 – February 2025. If you want to apply for a beamtime with SB operation only, you should indicate it clearly in your beamtime proposal. Please note that the FinEstBeAMS beamline has no chopper.

It might also be possible to arrange some SB shifts outside of the SB week if other beamlines at the 1.5 GeV ring agree with it. Please express your interest in combining SB shifts with your (multi-bunch) proposal by checking the corresponding box as a detector under the selection of the end station (available for the PLES and GPES) and motivate the need in your beamtime proposal.

Page manager: Antti Kivimäki June 28, 2024