Specifications

NOTE: The information contained in this page is taken from the website: www.wfl.elettra.eu
General Properties
Beamline Energy Resolution0.006 [eV] @ 44 [eV]
0.35 [eV] @ 1650 [eV]
0.025 [eV] @ 500 [eV]
Beamline Resolving Power6.6 * 103 [deltaE/E] @ 870 [eV]
1.5 * 104 [deltaE/E] @ 530 [eV]
1.2 * 104 [deltaE/E] @ 400 [eV]
1.2 * 104 [deltaE/E] @ 90 [eV]
1.6 * 104 [deltaE/E] @ 50 [eV]
5.5 * 103 [deltaE/E] @ 1650 [eV]
Beamline Energy Range44 - 1600 [eV]
Max Flux On Sample5 * 1012 [ph/s] @ 125 [eV]
2 * 1011 [ph/s] @ 1000 [eV]
6 * 1011 [ph/s] @ 1500 [eV]
Spot Size On Sample Hor250 - 350 [um]
Spot Size On Sample Vert10 - 350 [um]
25 - 350 [um]
Divergence Hor0.5 [urad]
Divergence Vert0.1 [urad]
Angle Of Incidence Light On Sample Value5 - 90 [degrees]
Control And Data Analysis
Control Software TypeLabview (for XAS/XMCD/XES/time resolved XAS) and SES for Scienta3000 (XPS)
Data Output Typespectra and images
Data Output Formatascii, txt, pxp, bin, Igor format
Softwares For Data Analysisin-house developed Igor Pro procedures and in-house developed Labview procedures, KolXPD


NOTE: the Photon flux is calculated at the maximum resolving power achievable with entrance and exit slit width set to 10 micrometer.
A further grating (SG4) provides 10 times higher flux in the same conditions (but lower resolution).

 
Since BACH employs two different undulators for different energy ranges, the user must select properly the undulator to work with. Important Note: the two undulators cannot be used simultaneously!!! When one of them is in use (gap below 100 mm) the other must be at the maximum gap (100 mm) and zero phase and zero tapering. If both gaps are below 100 mm a beam dump will occur and all beamlines will loose the beam!

High Energy Undulator

TypeUndulator
Available PolarizationLinear horizontal, Linear vertical, Elliptical, Circular
Variable PolarizationYes
Source Divergence SigmaX = 0.5 [urad], Y = 0.1 [urad]
Source Size SigmaX = 240 [um], Y = 50 [um]
Energy Range185 - 1600 [eV]
Number Of Periods44
Period48.36 [mm]

Low Energy Undulator

TypeUndulator
Available PolarizationLinear horizontal, Linear vertical, Elliptical, Circular
Variable PolarizationYes
Source Divergence SigmaX = 0.5 [urad], Y = 0.1 [urad]
Source Size SigmaX = 240 [um], Y = 50 [um]
Energy Range22 - 600 [eV]
Total Power200 [W]
Number Of Periods27
Period77.36 [mm]

 
8.1 (High Energy) From 175 eV-1650 eV First harmonic:175 eV-730 eV
LH: 177 eV-746 eV (gap19-gap50mm)
LV: ~367-780 (gap19-gap50mm)
CP: ~290-770 (gap19-gap50mm)
2.0 GeV
    First harmonic:247 eV-1030 eV
LH: ~247 eV-1074 eV (gap19-gap50mm)
LV: ~528-1100 eV (gap19-gap40mm)
CP: ~418-1119 eV (gap19-gap50mm)
2.4 GeV
8.2 (Low Energy) From 35/42 eV to more than 600 eV First harmonic (highest flux):35* eV-440 eV
*The lower Limit is dependent on the polarization and it is actually limited to 35 eV by the monochromator. 
LH: 16-20 eV (estimated)-140 eV
LV: 43 eV-325 eV
Circ: 30 eV-270 eV
2.0 GeV
    First harmonic (highest flux):42 eV-620 eV
*The lower Limit is dependent on the polarization. 
LH:  30 eV (estimated)-200 eV
LV:  61 eV-470 eV
Circ:  44 eV-385 eV
2.4 GeV
 

Monochromator BACH

Energy Range35 - 1650 [eV]
TypeVASGM
Resolving Power12000 [E/deltaE] @ 90 [eV]
6600 [E/deltaE] @ 867 [eV]
Number Of Gratings4
Grating Typespherical gratings
Pre-focusing Mirror Typeplane mirror

MONOCHROMATOR: ENERGY RANGES

SG1 44 eV-349 eV (35 eV-42 eV available under special request) high resolving power: 20000-6000 flux>1011
SG2 158 eV-597 eV high resolving power: 20000-6000 flux>1011
SG3 491 eV-1650 eV high resolving power: 15000-5000 flux>1011
SG4 301 eV-1650 eV medium resolving power: 10000-2000 flux>1012
 

 

Cryomagnet 6T XMCD

DescriptionCurrently NOT AVAILABLE to users. If interested for a long-term project please contact us.
XAS (X-ray Absorption Spectroscopy) in total eletron yield (drain current) and total fluorescence yield (photodiode), XMCD (X-ray Magnetic Circular Dichroism) and X(M)LD [X-ray (Magnetic) Linear Dichroism] under high magnetic fields (superconducting magnet) and at variable temperature 1.8 K-340 K. Optical ports for laser in-laser out. A surface preparation and sample growth facility is in preparation. UHV environment.
SpectrometerTotal electron yield drain current
-6.5 to +6.5 Tesla superconducting magnet
1.8 K-340 K cryostat
Base Pressure5 * 10-10 [mbar]
Sample
Sample TypeCrystal, Amorphous
Manipulator or Sample stage
Manipulator


Multispectroscopy XPS/ARPES/XAS/XES

DescriptionPES (Photoelectron Spectroscopy), automatic ResPES (Resonant Photoemission Spectroscopy), VUV and soft x ray ARPES (Angle Resolved Photoemission Spectroscopy), Temperature-programmed PES, XAS (X-ray Absorption Spectroscopy) in total electron yield (both drain current and a channeltron are available), partial electron yield (using the electron analyzer), total fluorescence yield (MCP), partial fluorescence yield (using the fluorescence grating spectrometer), XMCD (X-ray Magnetic Circular Dichroism) in remanence, X(M)LD [X-ray (Magnetic) Linear Dichroism] in remanence, SXES (Soft X-ray Emission Spectroscopy) and inelastic scattering spectroscopy RXES (Resonant X-ray Emission Spectroscopy), Low Energy Electron diffraction (LEED), Surface preparation and sample growth facilities. Variable sample temperature 120 K - 1300 K (sample
temperature down to 50 K possible with LHe cooling). Optical ports for laser in-laser out. UHV environment. Currently used also for pump-probe time resolved XAS in total fluorescence yield. Sample cell for fluoresce yield measurements in liquid environment.
MicroscopesNot available at the beamline. However an ex situ microscope facilities are available upon request.
Spectrometer1) Scienta3000 hemispherical electron energy analyzer for angle-resolved photoemission spectroscopy (energy resolution better that 3 meV and angular resolution better than 0.5°, quick acquisition mode to perform fast photoemission with 300 msec total acquisition time per spectrum. The same instrument can be used to acquire core levels, work function, VUV to soft x ray ARPES, automatic energy dependent ARPES, Partial Yield XAS (secondary or Auger electrons), together with the drain current from the sample (TEY), automatic resonant photoemission and temperature-programmed photoemission

2) ComIXS fluorescence spectrometer with grating for x-ray emission spectroscopy and partial fluorescence yield spectroscopy and medium resolution (~1 eV at 800 eV)- (ask if operative)

3) Channeltron and MCP (ask if available/installed)

4) Keithleys (428 and 6430) for drain current x-ray absorption spectroscopy

5) Ultrafast MCP for total fluorescence yield time-resolved x-ray absorption spectroscopy
Base Pressure2 * 10-10 [mbar]
Detectors Availablefast MCP
Drain Current
Endstation OperativeYes
Sample
Sample TypeCrystal, Amorphous
Other Sample Typeliquid (after contacting beamline scientist about feasibility)
Mounting Typeclamps, epoxy glue, silver paint, carbon tape...
Required Sample SizeX = 5000 [um], Y = 2000 [um], Z = 1000 [um]
Techniques usage
Absorption / NEXAFSTEY (drain current),PEY (secondary electrons measured by the Scienta analyser) , AEY (Auger electrons measured by the Scienta analyser), TFY (photon out measured by the MCP) ,PFY (energy resolved photon out by the ComIXS-currently not available to users)
Absorption / Time-resolved studiesOptical excitation of the sample is done by laser pulses (synchronized to either hybrid or multi bunch SR pulses), and probing is performed by time-delayed synchrotron radiation pulses.
Absorption / XMCDIn Remanenece after in situ magnetization with a permanent magnet of 0.5-1T or a variable magnetic field from 0 to 1 kGauss
Emission or Reflection / X-ray fluorescence (XRF)ComiX spectromenter
http://www.elettra.trieste.it/lightsources/elettra/elettra-beamlines/bach/bach-endstations/page-8.html?showall=
Photoelectron emission / Angular Resolved PESVUV and SOFT-X RAY ARPES from 44eV to 1650 eV.
Energy dependent ARPES with automatic control of the energy in the sequence
Energy resolution better that 3 meV and angular resolution better than 0.5°, quick acquisition mode to perform fast photoemission with 300 msec total acquisition time per spectrum
http://www.elettra.trieste.it/lightsources/elettra/elettra-beamlines/bach/scienta3000.html
Photoelectron emission / Photoelectron diffractionEnergy dependent PhD with automatic control of the energy in the sequence or Polar angle scans
Photoelectron emission / UPSShallow core levels and angle resolved valence band.
Energy dependent measurements with automatic control of the energy in the sequence
Work function measurements.
Photoelectron emission / XPSCore levels.
Resonant photoemission or energy dependent measurements with automatic control of the energy in the sequence.
Temperature-programmed XPS.
Quick acquisition mode to perform fast photoemission with 300 msec total acquisition time per spectrum
Scattering / Inelastic scatteringMedium-resolution soft x-ray RIXS. Currently not available to users.
Manipulator or Sample stage
Manipulator
DescriptionIn the Main chamber , the sample manipulator is mounted vertically on top of the experimental chamber. In the Main chamber two manipulators are available.
One is a LHe cryostat with 4 degrees of freedom. Its main features are the following:
X-Y (horizontal) travel = ±25 mm; Z (vertical) travel = 200 mm; Angular rotation (polar) = ±180°
Temperature range: 50 K (LHe) or 110 K (LN2)÷1300 K; The minimum temperature depends on the sample holder which is used. For instance using the new VG XL25HC sample holder with PBN and thermoucouple we have reached -4.3 mV on the sample (~100 K).
The temperature range is 250÷1500 K with home-made sample holders, for Si, SiC and Ge.

The other manipulator is a 5-degrees of freedom Omniax manipulator made by VG. This manipulator is currently offline without azimuth. We recommend prospective users to contact the beamline staff if they are interested to use the 5-axis Omniax instead of the Createc on the branch line A. Its main features are the following:
X-Y (horizontal) travel = ±25 mm; Z (vertical) travel = 200 mm; Angular rotation (polar and azimuthal) = ±180°;IMPORTANT NOTICE: Azimuthal rotation is not available at BACH now
Temperature range of the 5-degrees of freedom Omniax: 130÷1000 K (with XL25HC sample holder);
Degrees Of Freedom4
Translator Stages3

Sample Environment
Main XPS Chamber Environment
DescriptionUHV conditions. A special cell for fluorescence yield measurements of samples in liquid environment is available.
Pressure (min)2 * 10-10 [mbar]
Pressure (Max)1 * 10-6 [mbar]
Temperature50 - 1300 [K]

Preparation chamber Environment
DescriptionFor gas exposure at high partial pressure (>10-4 mbar) at temperatures between 300 K and 750 K, a dedicated chamber in vacuum connected to the preparation chamber can be used.
Pressure (min)5 * 10-11 [mbar]
Pressure (Max)1 * 10-5 [mbar]
Temperature300 - 1300 [K]

Sample Holders
Direct current heating sample holder
Descriptionsuitable for annealing in UHV of silicon, germanium, SiC

E-Beam sample holder

Omicron-plate compatibe sample holder
DescriptionThis sample holder can be used in combination with a vacuum suitcase. Please contact BACH beamline scientists for details.

PBN sample holderXL25HC: Heat and Cool block
DescriptionPBN annealing up to 1100K. Cooling down to ~130K with LN2.
Large area (~3 cm) to host several samples at the same time.
Transferable from different chambers.
Quick sample transfer from air to UHV
Thermoucouple can be fixed in contact with the sample
It can be used for temperature programmed XPS

PBN sample holder XL25VH: very hot block
Typeheating/cooling
DescriptionPBN annealing up to 1100K. Cooling down to ~130K with LN2 and ~50K with LHe.
Large area (~3 cm) to host several samples at the same time.
Transferable from different chambers.
Quick sample transfer from air to UHV
Thermocouple can be fixed in contact with the sample
It can be used for temperature programmed XPS

Magnetic Fields

Preparation Chamber

Descriptioncrystal cleaver
Scraper - diamond file / cleaver
Ar+/Ne+ ion sputtering system
1 Leak Valve
2-degree-of-freedom (theta, z) manipulator (continuous annealing up to 700 K, flash up to 1400 K)
Electro Magnet for in-plane magnetization at room temperature from 0 to 1 kGauss
Ports for user evaporators, including a retractable port with gate valve for fast mounting
Pressure gauge and Residual Gas Analyser . p<3x10-10 mbar
SpectrometerRGA
Base Pressure2 * 10-10 [mbar]
Endstation OperativeYes
Sample
Sample TypeCrystal, Amorphous

Time-resolved XAS

DescriptionThe experimental setup of the BRANCH A can also combine Laser and Synchrotron Radiation (SR) in order to study the dynamics of the photo-induced excited states of electronic and magnetic systems with pump-probe time-resolved x-ray absorption spectroscopy. Elettra Synchrotron radiation source provide radiation pulse widths sufficiently short to investigate dynamic processes in the time between 70 ps up to 0.5 μs. Typically, optical excitation of the sample is done by laser pulses (synchronized to either hybrid or multi bunch SR pulses), and probing is performed by time-delayed synchrotron radiation pulses.
SpectrometerFluorescence yield ultrafast MCP Hamamatsu, response time =100 ps
Base Pressure1 * 10-10 [mbar]
Detectors AvailableComIXS Fluorescence Spectrometer
Scienta3000 Electron Analyser
fast MCP
Drain Current
Sample
Sample TypeCrystal, Amorphous, Liquid


 

ComIXS Fluorescence Spectrometer

TypeFluorescence CCD spectrometer with grating
Pixel SizeX = 12.5 [um], Y = 12.5 [um]
Array SizeX = 2048 [pixel], Y = 2048 [pixel]
Passive or Active (Electronics)Active
Detection
Detected ParticleElectron

Drain Current

TypeTotal Electron Yield Drain Current for NEXAFS
DescriptionMeasurement of the drain current is performed by a 428 Keithley electrometer (from pA to nA)
Passive or Active (Electronics)Active
Detection
Detected ParticleElectron

fast MCP

TypeFluorescence yield ultrafast response MCP
DescriptionUltrafast MCP-Hamamatsu detector
Time ResolvedYes
Passive or Active (Electronics)Active
Detection
Detected ParticleElectron

Scienta3000 Electron Analyser

TypeElectron hemispherical analyser SCIENTA R3000
Time ResolvedYes
Passive or Active (Electronics)Active
Detection
Detected ParticleElectron



SCIENTA OPERATION MODES

1) Transmission or Angle resolved photoemission from 35-44eV to 1650eV with circular, linear horizontal or linear vertical polarization
2) Partial/Auger Electron Yield (CFS)
3) Resonant Photoemission (CIS)
4) Series of measurements (i.e. core levels at different photon energies, series of resonant photoemission, temperature programmed XPS) can be run automatically.

ARPES GEOMETRY


 

 


Off-Line Tools and Facilities

Tool/Instrument Specifications Location
Hot Plate 50° C-500° C
Max Load 5 kg.
Max dim. 200x200 mm.
On the table between BACH acquisition room and LASER hutch
Ultrasonic Cleaning Machine   On the table between BACH acquisition room and LASER hutch
Electrical conductive UHV compatible silver epoxy, silver paint and insulating glues   BACH chemical cabinet
UHV compatible Carbon, Kapton and Copper tape; Several sample Clamps   BACH acquisition room
Hot gun    
N2 gas line   close to the LASER hutch
Water cooling circuits   close to the LASER hutch
Electric Drill   Black box in the cabinet between BACH acquisition room and LASER hutch
Diamond Files, Sample preparation tools   BACH acquisition room
Pyrometer (reads above 300° C )   Cabinet or Main Chamber area
UHV Thickness monitor Sycon Instruments STM-100/MF (it can be mounted on the preparation chamber)
Vacuum sample storage box   Table close to the monochromator
Electromagnet (OFFLINE!) up to ~2 Tesla  
Magnetic coil in the prep chamber variable field up to 1 kGauss inside the preparation UHV chamber
Evaporators http://www.elettra.trieste.it/lightsources/elettra/elettra-beamlines/bach/bach-endstations/page-6.html?showall=  
Sample holders 
(http://www.elettra.trieste.it/lightsources/elettra/elettra-beamlines/bach/bach-endstations/page-5.html?showall=)

2 standard VG XL25VH

1 standard VG XL25HC

3 home-made sample carriers for heating by filament (for radiative sample heating up to 500° C or electron bombardment) (1 currently lended)

1 home-made sample carriers for heating by direct current up to 10 A (e.g. Si, Ge, SiC)

1 sample holder for standard Omicron Plates

Ultima modifica il Martedì, 28 Maggio 2019 17:39