10-11 December 2013
Swedish Agricultural University
Europe/Stockholm timezone
MAX IV Workshop on STXM
The aim of this workshop is to discuss the possibilities of Scanning Transmission X-ray Microscopy (STXM) for all kinds of research topics. As a primary focus we want to establish a dialogue between experienced users of STXM and interested newcomers to the technique, as input for their own research. Simultaneously, we want to collect user’s wishes and expectations for a STXM branchline at MAX IV in terms of the science; experimental setup and sample environment; further specifications (fields, cooling, etc.); and off-line facilities such a beamline should ideally offer. As part of the Phase IIa process, a combined STXM - Coherent Imaging beamline (‘Softi-MAX’) was included in the VR application this year.
In this workshop we therefore wish to offer users an opportunity to influence the design of such a branchline at an early stage. The outcome of the workshop should serve as essential input, either when a successful result of the Phase IIa application awards funding for the SoftiMAX beamline, or towards the Phase IIb application that will be submitted in March 2014.
The workshop is open to our entire user community, but registration in advance is required. The number of attendees is limited to 50, and participation will be on a first come first serve basis. 

In order to promote discussion we invite possible present and future STXM users to submit an abstract for a presentation of their own research, to form a starting point for real experiments and wishes for the STXM end-station and branchline at MAX IV. From the entrees 5-10 presentations can be selected.

A list of hotels/B&Bs in Umeå can be found on the useful information  page. A dinner, two lunches and coffee breaks are included in the workshop, for which there is no registration fee. We will update information regarding the program/workshop’s facilities on this page regularly.

DATE: 10-11 December, 2013
VENUE: “Aspen” lecture room at SLU, Umeå
ORGANISERS: Karina Thånell (Schulte) – karina.thanell@maxlab.lu.se

This workshop receives funding from a STINT initiation grant
Swedish Agricultural University

What is STXM?

In its simplest form STXM offers chemically specific information on nm-size areas of a thin sample. The basic technique uses a mono-energetic x-ray beam that is focused through a Fresnel zone plate and an aperture onto the sample. The focal point is typically 15-50 nm in diameter. A microscopic image of the sample is generated by monitoring the X-ray signal transmitted through the thin specimen (from nm to micrometers) as it is raster-scanned at the focus of the x-rays. The contrast is hence given by the elements that do/don't absorb x-ray photons of a specific energy. In this way C can be differentiated from O, but also C-H from C-O as they have different absorption energies - the energy resolution of the beamline is around 0.1 eV.

Alternatively, x-ray absorption spectra over the 15-50 nm beam diameter are measured by holding the beam focused on the spot of interest while the photon energy is scanned. These two procedures can also be combined, when scanning  over a larger area.

One of the main advantages of STXM is that the sample can be mounted in air (with sufficiently short X-ray path length), in a He atmosphere, or even sandwiched between two X-ray transparent silicon nitride windows. The latter approach is used to study wet samples such as eg. hydrated polymers or biological material, but can also be used in conjunction with gas flow. The focus on the soft x-ray regime makes elements like carbon, nitrogen and oxygen etc. accessible for analysis as well as the Fe, Ni and Co 2p levels important in magnetism research. Most modern STXM set ups also provide the possibility for fluorescence measurements (materials with elements showing limited x-ray transmission) and 3D scanning of samples.