TEMPO is a soft x-ray beamline optimized for dynamic studies of the electronic and magnetic properties of materials. The project gathers various spectroscopic studies around its specificity, i.e. taking into account the temporal variable. This regards more specifically:

  • the determination of the kinetics of chemical reactions at interface and surface by rapid photo-emission in the millisecond range. The high flux coupled to the high energy resolution of the electron energy analyser and of the beamline will allow the user to study the evolution of the chemical environment (surface coordination, chemical bonding with different elements) of selected chemical atoms at the surface using spectroscopic signatures in the electronic states. Physisorption kinetics, chemisorption or dissociation of molecules on a substrate, interface formation and interdiffusion. The understanding of these processes is the key point to build new magnetic materials or to control chemical reactivity and catalytic properties.
     
  • the dynamics of magnetisation reversal in nanostructures, using the temporal characteristics of Soleil at the scale of dozens of picoseconds , a problem of major significance for the magnetic storage of information at ultra-high density. These experiments will be performed using different techniques with different probing depths : X-ray magnetic circular dichroism, Magnetic dichroism in photoemission.
     
  • carrying out pump-probe experiments with two photons(laser + synchrotron radiation) for the study of excited states using synchrotron impulses in the temporal range of a picosecond.
Beamline Energy Resolution
0.04 [eV] @ 400 [eV]
Beamline Resolving Power
1 * 105 [deltaE/E] @ 50 [eV]
1 * 104 [deltaE/E]
Beamline Energy Range
50 - 1500 [eV]
Max Flux On Sample
2 * 1015 [ph/s] @ 100 [eV]
Spot Size On Sample Hor
100 - 1000 [um]
Spot Size On Sample Vert
20 - 1000 [um]
Photon Sources

Source

Type
Undulator
Period
44 [mm]
Note
The beamline is equipped with two APPLE II helical insertion devices. They have periods of 44 mm and 80 mm and allow us to cover the whole energy range of the beamline using the first harmonic.
Monochromators

Monochromator

Type
The monochromator is composed by three plane gratings and two spherical mirrors. The gratings presents a Variable Line Spacing (VLS) to focus on the exit slits and a Variable Groove Depth (VGD) to optimize total photon flux and harmonic rejection at each photon energy.
The monochromator is then characterized by two optical paths : one for low energy ranges and the other for high energy ranges.
Grating Type
LOW ENERGY OPTICAL PATH (MIRROR A) :
Grating 350 t/mm 40/120 eV
Grating 800 t/mm 95/280 eV
Grating 1500 t/mm 180/540 ev

HIGH ENERGY OPTICAL PATH (MIRROR B):
Grating 800 t/mm 330/825 eV
Grating 1500 t/mm 620/1500 eV
Endstations or Setup

Station exp #1: UHV Photoémission

Description
- UHV Photoemission:
The main branch of the TEMPO beamline is equipped with a UHV system for surface science experiments. It is composed by a main chamber equipped with a Scienta SES 2002 electron energy analyzer (equipped with a delay line detector) and a preparation chamber with a sample transfer system and a fast entry lock. Ar- sputtering, water cooled evaporators and LEED characterization are available. We have developed two sample environments: one for magnetic dichroism experiments where about 100 Oersted can be applied in the measuring position and one for direct heating of semiconductor samples by current flow.

- Detector For Time Resolved experiments:
An important part of the TEMPO beamline scientific project is based on time resolved photoemission experiments performed using a pump probe technique. Possible applications are to studies of the electronic structure of laser excited states or the dynamics of surface magnetization.
The relaxation time of these phenomena can be longer then the interbunch period. It is then indispensable to associate each detected photoelectron to the synchrotron bunch which created it. If this identification is possible , then each repetition rate of the pump can be used for the experiments and the state excited by the laser pump can be probed by the Syncrotron Radiation pulse as a function of the delay Δt between the two pulses.
The time resolution of the experiment is then limited only by the S.R. pulse width: 30 ps at SOLEIL
We modified the Scienta SES 2002 electron energy analyser by replacing the CCD Camera by a delay line detector (G.Cautero and coworkers, Elettra, Trieste, It) which can associate each detected photoelectron to the Soleil Clock. This new configuration allows us to perform photoelectron spectroscopy experiments using the isolated bunch when Soleil is injected in hybrid mode.
Endstation Operative
Yes

Sample

Sample Type
Liquid

Station exp #2

Description
XPEEM from Lab. L. Néel (Grenoble):
The PEEM from Louis Néel Laboratory (Jan Vogel) has been installed on the branch line since 2008 to perform magnetization dynamics experiments.
Endstation Operative
Yes

Sample

Sample Type
Gas
Techniques
Absorption
  • NEXAFS
  • Time-resolved studies
  • XMCD
Emission or Reflection
  • Time-resolved studies
Photoelectron emission
  • Angular Resolved PES
  • Time-resolved studies
  • XPS
Disciplines
Chemistry
  • Atoms, molecules, clusters and gas-phase chemistry
  • Catalysis
  • Physical Chemistry
Material Sciences
  • Technique Development - Material Sciences
Physics
  • Hard condensed matter - electronic properties
  • Quantum electronics & optics
  • Surfaces, interfaces and thin films
control/Data analysis
Control Software Type
  • Labview
Data Output Type
  • .opj, .dat,
Data Output Format
  • ASCII and IGOR format
Softwares For Data Analysis
  • IGOR, ORIGIN
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