The Sigray QuantumLeap X-Ray Absorption Spectroscopy System – Chemical Specification and Electronic Structure with X-Ray Absorption Spectroscopy. We answer your questions in a series of articles about the QuantumLeap.
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What sample concentration can the QuantumLeap XAS cover?
The sample concentration the Quantum Leap XAS mode can cover is between 0.1-100% whilst the XES mode can cover <0.1%.
What X-ray energy range can the QuantumLeap cover?
There are currently two variations of the QuantumLeap XAS system.
The first is the QuantumLeap 410 which can cover energies between 4.1 – 10 keV
The second, which is an add-on to the 410, is the QuantumLeap 210 which can cover energies between 2.1 – 10 keV
With XANES, the energy of operation can be further increased to 12keV however, data acquisition will be reduced by up to 4x.
Can carbides, nitrides and oxides be detected and quantified with the QuantumLeap XAS?
Whilst light elements such as C, N and O cannot be detected by the standard configuration of the QuantumLeap XAS and quantified directly, due to their K- and L- edge energies being much lower than the 2.1keV minimum energy, differences between oxidation states of an element of an interest can be.
Carbon (284 eV), Nitrogen (410 eV), Oxygen (543 eV), Fluorine (697 eV), Sodium (1071 eV), Magnesium (1303 eV), Aluminum (1559 eV), Silicon (1839 eV) all have K- and L- edge energies lower than the 2.1keV QuantumLeap minimum energy and so cannot be measured.
What is the flux per eV for XAS?
For XANES, flux achievable is ~5×105 photons/s/eV at the sample plane with the photons being distributed over a given energy coverage
For EXAFS, flux achievable is ~1×108 photons/s at the sample
To note, the QuantumLeap system acquires the full bandwidth at once, as opposed to scanning systems where crystal rotation is necessary per eV and acquiring per step.
How much powder is required for performing a single measure on the QuantumLeap XAS?
About 1g of sample is required for a single measurement if the sample is in powder form.
What film size/thickness can be measured with XAS?
Film thickness should be between 1 – 2 x the attenuation of for the element of interest. The attenuation length can be determined here.
The energy to use is dependent on absorption energy.
What software is used for XAS analysis?
Whilst Sigray uses the ATHENA software, SIXPACK is the preferred software for the synchrotron facility.
Click here for more information on the QuantumLeap XAS.
