Labs and instruments

Scanning Transmission X-ray Microscope

The STXM is one of the two end stations of the DEMETER beamline. The operating principle of the STXM is scanning of the sample in the focus of the Fresnel zone plate, which for this device is the lens focusing X-rays. In the next step, the detector measures the intensity of the radiation passing through the sample and, on the basis of the intensity images recorded by the detector, it is possible to calculate the absorption X-ray radiation in a selected place of the tested system.

Contact:

Krzysztof Matlak
Tel: +48 12 664 4124 (office)

Technical specifications

The source for the STXM end station is elliptically polarized undulator, which enables to cover the energy range from 100 to 2000 eV. The undulator allows measurements using linear, circular and elliptical polarization.

Sample environment

In principle, measurements using STXM end station can be performed both under vacuum conditions (up to 1e-7 mbar) and in the presence of the selected gases at a pressure equal to, or less than atmospheric pressure. The available gases are : He, Ar, O₂, N₂, CO₂. The standard working mode at STXM microscope is transmission but measurements in the X-ray fluorescence spectroscopy mode (XRF) are also possible. The available detectors are: photodiode (PD), avalanche photodiode (APD) and photomultiplier tube (PMT).

The main requirement for samples tested in the STXM end station is proper optical density, because in the case of too thick sample signals are not transmitted and in the case of too thin sample the absorption is too weak.

Detailed information can be found on the beamline’s main homepage.

The DEMETER beamline is still under commissioning and it may influence on overall beamline performance. We can not guarantee all beam parameters which may differ from the theoretical ones during experiment.