Elettra
BL 10.2 R - BaDElPh

Low-Energy Angle-Resolved PhotoEmission Spectroscopy (LE-ARPES)

The Band Dispersion and Electron-Phonon coupling (BaDElPh) beamline provides photons in the energy range 4.6-40 eV with high flux, high resolving power, and horizontal-vertical linear polarization. The beamline serves an end station to perform primarily high-resolution angle-resolved photoemission spectroscopy (ARPES) experiments in the low photon energy regime. Photon energies lower than 15 eV provide enhanced bulk sensitivity, allow for the highest momentum and energy resolution, and are useful in tuning matrix elements which vary rapidly at low energy. The availability of such low photon energies makes BaDElPh unique among the other ARPES beamlines at Elettra and around the world.

Beamline Energy Resolution
3 * 10-1 [meV] @ 9 [eV]
6 * 10-1 [meV] @ 23 [eV]
1 [meV] @ 31 [eV]
Beamline Resolving Power
3 * 10-5 [deltaE/E] @ 9 [eV]
2 * 10-5 [deltaE/E] @ 23 [eV]
3 * 10-5 [deltaE/E] @ 31 [eV]
Beamline Energy Range
4.6 - 40 [eV]
Max Flux On Sample
6 * 1012 [ph/s] @ 9 [eV]
2 * 1012 [ph/s] @ 23 [eV]
1 * 1012 [ph/s] @ 31 [eV]
Spot Size On Sample Hor
300 - 400 [um]
Spot Size On Sample Vert
10 - 400 [um]
Angle Of Incidence Light On Sample Value
20 - 110 [degrees]
Photon Sources

Figure-8 undulator

Type
Undulator
Available Polarization
Linear horizontal, Linear vertical
Variable Polarization
Yes
Energy Range
4.6 - 50 [eV]
Number Of Periods
32
Period
140 [mm]
Additional Lightsources

VUV source

Type
He discharge lamp
Central Wavelength/Energy
21 [eV]
Beam shape
Gaussian
Polarisation
Unpolarized

x-ray source

Type
Lamp based on x-ray fluorescence of Al and Mg solid targets
Central Wavelength/Energy
1253 [eV]
Beam shape
Gaussian
Polarisation
Unpolarized
Monochromators

NIM monochromator

Energy Range
4.6 - 40 [eV]
Type
4-m-long normal incidence monochromator (NIM) with a constant included angle of 5°
Resolving Power
3 * 10-5 [deltaE/E] @ 9 [eV]
Number Of Gratings
3
Grating Type
1) Al/MgF2 grating with 1500 l/mm, laminar profile, photon energy range 4.6-13 eV.
2) SiC grating with 3000 l/mm, laminar profile, photon energy range 15-19 eV.
3) Pt grating with 3000 l/mm, blaze profile, photon energy range 14-40 eV.
Pre-focusing Mirror Type
Spherical mirror. The bare silicon portion of the surface of the mirror is used for photon energies up to about 13 eV while the reflectivity of the Pt-coated part is suitable for higher photon energies.
Refocusing Mirror Type
Gold-coated toroidal mirror.
Other Optics

Switching mirror

Description
The silicon plane-switching mirror deflects the radiation from the Figure-8 undulator from the IUVS beamline toward the BaDElPh branch.
Endstations or Setup

Endstation

Diffractometer
Omicron SPECTALEED low enery electron diffraction (LEED) optics
Spectrometer
SPECS Phoibos 150 hemispherical electron analyzer with a 2D-CCD detector
Base Pressure
2 * 10-11 [mbar]
Detectors Available
2D-CCD imaging detector
Endstation Operative
Yes

Sample

Sample Type
Crystal
Other Sample Type
Policrystal, thin film, powder
Mounting Type
Fixed on home-made sample flag
Required Sample Size
X = 10 [mm], Y = 10 [mm], Z = 8 [mm]
X = 1 [mm], Y = 1 [mm], Z = 0.1 [mm]

Manipulator or Sample stage

Description
The sample manipulator has five degree of freedom (xyz translations, polar and azimuthal rotational axes). It is based on a open-cycle helium cryostat (ARS LT-3M), is fully motorized (by stepper motors for the polar rotation and xyz translations and by the piezo motor for the azimuthal rotation), and it can be remotely controlled.
The temperature can be measured by a calibrated C-type thermocouple and by a standard silicon diode (DT-470) installed next to the sample and on the cold finger, respectively. The head of the cryostat includes also a cartridge heater allowing a remote control of the temperature in the range 5-400 K.
Degrees Of Freedom
5
Translator Stages
3
Cradles
2
Positioning Precision
X = 5 [um], Y = 5 [um], Z = 5 [um]
Range Of Movement
X = 50 [mm], Y = 50 [mm], Z = 600 [mm]

Sample Environment

Description
The Experimental or Analysis chamber is in mu-metal and houses the electron energy analyzer, a SPECS Phoibos 150 with a 2D-CCD detector system, a high-intensity VUV source (He, Omicron HIS 13), a conventional X-ray source (Al & Mg, PSP TX400), a low-energy electron diffraction (LEED) optics (Omicron SpectaLEED), a home-made gas-cell, and a residual gas analyzer (SRS RGA200). It is connected through a valve to the UHV Preparation chamber.
Pressure (min)
2 * 10-11 [mbar]
Pressure (Max)
1 * 10-7 [mbar]
Temperature
10 - 400 [K]
Description
In the fast-entry chamber up to two samples per time can be loaded from air and in about 60 minutes can reach a pressure of about 10^-6 mbar. It is connected through a valve to the UHV Heater chamber.
Pressure (min)
2 * 10-7 [mbar]
Pressure (Max)
1 * 103 [mbar]
Description
The Heater chamber houses an electron bombardment heater stage for high-temperature (up to about 2400 K) annealing of the sample and a 7-slot sample flag parking device. It has also several free flanges to mount the needed tools for the required sample preparation (cleavage, scraping, gas treatment, quartz microbalance...) and for UHV in-situ growth of thin films. It is connected through valves to the fast-entry lock and the UHV Preparation chamber.
Pressure (min)
3 * 10-10 [mbar]
Pressure (Max)
1 * 10-6 [mbar]
Temperature
300 - 2400 [K]
Description
The Preparation chamber houses the five degree of freedom liquid-He cryostat manipulator and it is normally equipped with an ion sputter gun (Varian), a quartz microbalance, and a silver evaporator. It has also several free flanges to mount the needed tools for the required sample preparation (cleavage, gas treatment...) and for UHV in-situ growth of thin films. It is connected through valves to the UHV Heater and Analysis chambers.
Pressure (min)
3 * 10-11 [bar]
Pressure (Max)
1 * 10-6 [bar]
Temperature
10 - 400 [K]

Sample Holders

Type
heating / cooling devices
Description
Home-made sample flag compatible with Omicron- and Specs-like flag sample holders. The Omicron- and Specs-like flag sample holders can be used with a suitable adapter.
Detectors

2D-CCD imaging detector

Type
CCD sensor
Description
by SPECS with PCO PixelFly camera
Time Resolved
Yes
Pixel Size
X = 9.9 [um], Y = 9.9 [um]
Array Size
X = 640 [pixel], Y = 480 [pixel]
Passive or Active (Electronics)
Active
Dynamic Range
1 * 103
Output Readout Software
SpecsLab2

Detection

Detected Particle
Electron
contacts
Luca PETACCIA
Techniques
Photoelectron emission
  • Angular Resolved PES
  • UPS
Disciplines
Material Sciences
  • Other - Material Sciences
Physics
  • Hard condensed matter - electronic properties
  • Nanophysics & physics of confined matter
  • Surfaces, interfaces and thin films
Address
BaDElPh beamline
Elettra - Sincrotrone Trieste S.C.p.A.
S.S. 14 Km 163.5 in AREA Science Park
34149 Basovizza, Trieste
Italy
control/Data analysis
Control Software Type
  • LabVIEW, SpecsLab2
Data Output Type
  • Spectra, images
Data Output Format
  • Text, Igor, sp2 formats
Softwares For Data Analysis
  • Igor Pro
Equipment That Can Be Brought By The User
Evaporators and other tools for sample preparation usually not available at the beamline. Anyway, users are invited to verified with the local contact on the possibility to connect their own equipment at the beamline end station.