The Low Density Matter (LDM) beamline is presently in operation at the FERMI Free Electron Laser (FEL) facility. It is designed to investigate atoms, molecules, and their aggregates (clusters) in an unperturbed environment (a supersonic jet in vacuum).
The LDM endstation is based on a modular design which includes interchangeable sources for high- and low-temperature jets, helium nanodroplets, rare-gas and water clusters, metal clusters, and radical species.
Simultaneous detection of electrons, ions, and photons allows a complete characterization of the target species, under the intense electromagnetic field produced by FERMI.
Additional Lightsources
Seed Laser for Users (SLU)
Laser type
Ti:Sapphire
Central Wavelength/Energy
795 [nm]
Wavelength fluctuations
1 * 10-3 [%]
Spectral Bandwidth FWHM
18 [nm]
Tunability
1 [%]
Beam shape
Gaussian
Other beam shape
M2<1.5
Pulse duration FWHM
65 [fs]
Polarisation
Linear Horizontal, Linear Vertical, Circular
Other polarisation
All linear and circular polarizations available
Pulse repetition rate
50 [Hz]
Maximum pulse energy
1 * 10-3 [J]
Pulse energy fluctuations
5 * 10-3 [sigma]
Peak power
20 * 109 [W]
Special modes
Second and Third harmonic generation available (~390 nm; ~260 nm)
Endstations or Setup
LDM
Base Pressure
1 * 10-9 [mbar]
Detectors Available
VMI
ion TOF
Wide-angle scattering
MBES
ion TOF
Wide-angle scattering
MBES
Endstation Operative
Yes
Detectors
ion TOF
Type
ion time-of-flight (TOF) mass spectrometer
Description
on time-of-flight (TOF) mass spectrometer. Mass resolution: approximately 1400 when operating alone; approximately 350 when operating together with electron VMI (@30 eV maximum electron energy)
Passive or Active (Electronics)
Active
Detection
Detected Particle
Ion
MBES
Type
Magnetic bottle electron spectrometer
Passive or Active (Electronics)
Active
Detection
Detected Particle
Electron
VMI
Type
electron/ion imaging detector
Description
Velocity Map Imaging (VMI) detector. Operating voltages can be set to detect electrons or ions. Tested to maximum kinetic energies up to 60 eV.
Pixel Size
X = 6.5 [um], Y = 6.5 [um]
Array Size
X = 2560 [pixel], Y = 2160 [pixel]
Passive or Active (Electronics)
Active
Detection
Detected Particle
Electron
Wide-angle scattering
Pixel Size
X = 6.5 [um], Y = 6.5 [um]
Array Size
X = 2560 [pixel], Y = 2160 [pixel]
Passive or Active (Electronics)
Active
Detection
Detected Particle
Photon
Techniques
Ion Spectroscopy
- Ion imaging
- Mass spectrometry
Photoelectron emission
- Angular Resolved PES
- Time-resolved studies
- UPS
- XPS
Scattering
- Coherent scattering
- Time-resolved scattering
- Wide angle scattering
Disciplines
Chemistry
- Other - Chemistry
Physics
- Atomic & molecular physics
control/Data analysis
Control Software Type
- TANGO
Data Output Type
- sigle-shot VMI images; single-shot TOF spectra; single-shot diffraction images; single-shot FEL and end station parameters;
Data Output Format
- HDF5
Softwares For Data Analysis
- In-house GUIs for basic real-time data reduction (TANGO; Python). In-house algorithms for fast basic data reduction (Matlab; Python; IgorPro). Abel inversion software (pBasex)
