Swiss Light Source

X-Treme pic.JPG

X-Treme / X07MA:
X-ray absorption spectroscopy at high magnetic field and low temperature

The X-Treme beamline produces a high flux of soft x-rays with variable polarization (circular left, circular right and linear polarization in any angle between 0 and 90 degrees) from an Apple-II undulator source.

The end station is equipped with a superconducting 2D vector magnet operating at 7 T single direction or 2 T vectorial field and a 2 K sample insert. The end-station is also equipped with an in-situ sample preparation system and a variable-temperature scanning tunneling microscope.

The beamline mostly focuses on measurements involving x-ray magnetic circular (XMCD) and linear dichroism (XLD, XMLD) at transition metal L2,3-edges (transition 2p -> 3d), lanthanide M4,5 edges (transition 3d -> 4f) and oxygen or nitrogen K-edges (transition 1s -> 2p). Typical systems studied are single atoms on surfaces; molecules or single-molecule magnets in bulk or on surfaces; superlattices and ultra-thin films. Different detection modes are available: total electron yield, total fluorescence yield, transmission and x-ray excited optical luminescence.

Beamline Resolving Power
5 * 103 [E/deltaE] @ 700 [eV]
Beamline Energy Range
400 - 2000 [eV]
Max Flux On Sample
1 * 1012 [ph/s] @ 700 [eV]
Spot Size On Sample Hor
0.2 - 0.5 [mm]
Spot Size On Sample Vert
0.03 - 2.5 [mm]
Angle Of Incidence Light On Sample Value
20 - 90 [degrees]
Photon Sources

Apple-II undulator

Available Polarization
Linear variable, Circular
Variable Polarization
Energy Range
150 - 2000 [eV]
Number Of Periods
54 [mm]

Plane grating Monochromator

Energy Range
150 - 2000 [eV]
Plane grating monochromator. Operates with incoming collimated light which allows free choice of cff value, which gives one more possibility for adjusting energy resolution, x-ray flux and high harmonic rejection
Resolving Power
1 * 104 [deltaE/E]
Number Of Gratings
Grating Type
1200l/mm laminar
900l/mm blazed
600l/mm blazed
Pre-focusing Mirror Type
Refocusing Mirror Type
Endstations or Setup

Superconducting magnet

Vector magnet. 7T uniaxial along x-ray beam. 2T vectorial in horizontal plane. Sweep rate: 2T/min for uniaxial 7T magnet and 0.36T/min for vectorial mode. Sample temperature down to 2.5-3.0K.
In-situ sample preparation chamber with evaporators, LEED, STM, heating stage and ion gun.
Detection modes: total electron yield, total fluorescence yield, x-ray excited optical luminescence
Base Pressure
5 * 10-11 [mbar]
Endstation Operative


Sample Type
Crystal, Amorphous, Powder
Mounting Type
With silver paint indium foil. Mounted directly on sample holder or omicron plate.
Required Sample Size
X = 1 [mm], Y = 1 [mm], Z = 0.1 [mm]
X = 10 [mm], Y = 10 [mm], Z = 1 [mm]

Sample Environment

2.5 - 350 [K]

Magnetic Fields

DC Fields
7T uniaxial or 2T vectorial
Max DC Field
7 [T]
Jan Dreiser
Cinthia Piamonteze
  • XMCD
  • Physical Chemistry
Engineering & Technology
  • Nanotechnology & production processes
Material Sciences
  • Knowledge based multifunctional materials
  • Other - Material Sciences
  • Hard condensed matter - electronic properties
  • Nanophysics & physics of confined matter
  • Surfaces, interfaces and thin films
control/Data analysis
Control Software Type
  • P-shell (including free python scripting) / EPICS
Data Output Type
  • X-ray absorption spectra or field dependent XMCD
Data Output Format