BM31 is specialized X-ray Absorption Spectroscopy (XAS) and High Resolution Powder
Diffraction (HRPD) beamline.
The beamline is designed in a flexible way to measure XAS and HRPD or even combination
of both techniques on the samples under different experimental conditions
(heating, cooling, in situ catalytic conditions etc).
X-ray Absorption Spectroscopy (XAS) is a powerful structural technique to investigate the short-range
environment around selected atomic species in condensed matter. XAS is applicable for the
fundamental studies of structural properties in materials like:
BM301 is designed to perform experiments, which require the capabilities of most second-generation
synchrotron sources. The main characteristics are the following:
|Monochromator||Water-cooled double-crystal monochromator with piezo for second crystal|
|Monochromator crystals||Flat Si pair and Flat Si pair|
|Spectral range||4 - 70 keV|
|Intrinsic resolution (DE/E)||Si: 1.4 x 10-4 Si: 0.3 x 10-4|
|Mirrors||Two flat mirrors with Cr and Au surfaces for harmonic rejection|
|Spot size||up to 10 mm horizontal x 0.6 mm vertical|
Flux factor of 3 less for Si  compared to Si 
The following options are available:
We use standard ESRF spec software and have full support of BLISS group.
When submitting beam time proposals, please be as clear and accurate as possible in terms of the
concentration of the absorber in your sample. This determines the type of detection system to be
used and permits a much better estimation of the necessary number of shifts to perform the experiment.
The information about the sample environment (temperature, gases etc) is also very important
to plan the experiment in advance.
A robust 2-circle diffractometer is available for High Resolution Powder Diffraction measurements.
Each circle has a high precision encoder mounted directly on the rotary axis.
The diffractometer is currently equipped with 6 counting chains, meaning that 6 complete patterns
are collected simultaneously, with an offset in 2-theta. The angular offset between the detectors has
been kept to very small (~1.1 deg) in order to keep the total data collection time to a minimum.
An Si-111 analyser crystal is mounted in front of each detector (Na-I scintillation counter), resulting
in an intrinsic resolution (FWHM) of approx. 0.01 deg at a wavelength of 1 A. The available wavelength
range for the instrument is 0.4 to 1.2 A.
Transmission (capillary) measurements can be perfomed between 5 and 1023 K. A flat plate sample
spinner as well as a texture attachment can be mounted. Avalable on the beamline are thus a cryostat
for temperatures between 4 and 298 K.
The environment in the furnace can be controlled with both oxidizing and inert atmospheres.