CASSIOPEE | WayForLight

Synchrotron SOLEIL

CASSIOPEE

The CASSIOPEE beamline is a soft X-ray beamline dedicated to high resolution ARPES, spin-resolved photoemission and resonant spectroscopies in the 8 eV-1500 eV photon energy range. This wide energy range allows both surface and bulk studies of condensed matter. The beamline uses two undulators as a source with high flux and adjustable polarisation. The energy is selected by a high resolution PGM (Plane Grating Monochromator) with VLS (Variable Line Spacing) and VGD (Variable Groove Depth) gratings for best efficiency and spectral purity of the light. After the monochromator, the beamline is divided into two branches, supplying photons to two end stations (Spin-resolved Photoemission, and High Resolution Angle-resolved Photoemission), both connected to a Molecular Beam Epitaxy chamber for sample growth and caracterisation.

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Beamline Energy Resolution

6 * 10^-3 [eV] @ 20 [eV]

Beamline Resolving Power

3 * 10^-4 [E/deltaE] @ 20 [eV]

Beamline Energy Range

8 - 1500 [eV]

Max Flux On Sample

5.5 * 10¹⁰ [ph/s] @ 50 [eV]

Spot Size On Sample Hor

50 - 75 [um]

Spot Size On Sample Vert

25 - 50 [um]

Angle Of Incidence Light On Sample Value

0 - 90 [degrees]

Photon Sources

HU256

Type

Undulator

Available Polarization

Circular

Variable Polarization

Yes

Energy Range

8 - 150 [eV]

Number Of Periods

Period

256 [mm]

HU60

Type

Undulator

Available Polarization

Linear horizontal, Linear vertical, Circular

Variable Polarization

Yes

Energy Range

100 - 1500 [eV]

Number Of Periods

Period

60 [mm]

Monochromators

Monochromator

Type

SX700 monochromator

Endstations or Setup

ARPES

Description

6-axis manipulator
Temperature from 13 to 300K

Spectrometer

Scienta R4000

Base Pressure

1 * 10¹⁰ [mbar]

Endstation Operative

Yes

Sample

Sample Type

Crystal

Mounting Type

Omicron plate

Manipulator or Sample stage

Description

In-house developped cryogenic sample holder. Temperature from 13 to 300 K

Degrees Of Freedom

Translator Stages

Cradles

Positioning Precision

X = 0.01 [mm], Y = 0.01 [mm], Z = 0.01 [mm]

Range Of Movement

X = 8 [mm], Y = 8 [mm], Z = 10 [mm]

MBE

Description

The CASSIOPEE MBE chamber is equipped for surface science: Ion gun, LEED, RHEED, Auger Spectroscopy and 3 sample stages:
1. Electron bombardment heating and phi rotation for RHEED measurement
2. Liquid N2 cooling
3. Direct current heating

Base Pressure

1 * 10¹⁰ [mbar]

Endstation Operative

Yes

Sample

Sample Type

Liquid

Manipulator or Sample stage

Degrees Of Freedom

Translator Stages

Cradles

Spin-resolved photoemission

Description

The Spin-Resolved Photoemission experiment is equipped with a Scienta SES2002 electron analyzer, which has been modified by the Scienta company to incorporate a Mott detector for spin analysis (see Figure 2). Part of the electron beam is sent towards the usual Scienta 2D detector, while the rest goes towards the Mott detector through transfer optics. The analyzer is mounted with horizontal slits. Angular resolution is then achieved in the horizontal direction. To accept the Mott detector, the 2D detector has been reduced to 1”, thus reducing the angular acceptance of the analyzer to ±8°.

Spectrometer

Scienta SES-2002

Base Pressure

1 * 10¹⁰ [mbar]

Sample

Sample Type

Crystal

Mounting Type

Omicron plate

Manipulator or Sample stage

Degrees Of Freedom

Translator Stages

Cradles

contacts

Bertran François

Le Fèvre Patrick

Julien Rault

Techniques

Photoelectron emission

Angular Resolved PES
Spin-resolved ARPES
UPS
XPS

Disciplines

Physics

Hard condensed matter - electronic properties
Hard condensed matter - structures
Surfaces, interfaces and thin films

control/Data analysis

Control Software Type

Igor pro

Data Output Type

spectra or images

Data Output Format

ascii or Igor pro packed experiments

Softwares For Data Analysis

Igor pro

Equipment That Can Be Brought By The User

Vacuum suitcase
Evaporators