FemtoLEED 8000 | © Scienta Omicron
FemtoLEED DLD L800 with integral shutter.
FemtoLEED 8000 | © Scienta Omicron
FemtoLEED DLD L800 with integral shutter.
Digital LEED AES Controller Display Model LPS075-D | © Scienta Omicron
Model LPS075-D power supply for LEED operation.
Microchannel plates power supply controller | © Scienta Omicron
Microchannel plates power supply controller.

FemtoLEED DLD L800

Nano-Scale Measurements of Surface Periodic Structures with Femto-Ampere Electron Probe

LEED

  • Primary electron beam in the range of Femto Ampere
  • Electron diffraction on insulating single crystal samples
  • Large coherence width
  • Powerful operation with digital LEED controller

The Femto-LEED with integral shutter enables nano-scale measurements of surface periodic structures with a femto-ampere electron probe. Instead of a fluorescent screen, it uses a delay line detector and allows for fully digital operation.

More Information

Applications

Display of Silicon (111) with 50 eV beam energy, 35 V GND | © Scienta Omicron
Silicon (111) with 50 eV beam energy, 35 V GND.

With its primary electron beam in the range of Femto Ampere, the FemtoLEED DLD L800 is specifically useful for investigations on sensitive organic samples. The fully digital system negates the need for an external CCD camera for live image capture. 

Display of Silicon sample (185 deg) with 10 eV beam energy from the FemtoLEED 800 | © Scienta Omicron
Silicon sample (185 deg) with 10 eV beam energy.
Output of a magnesium oxide sample from the FemtoLEED 800.  | © Scienta Omicron
Magnesium Oxide sample.
Display of Magnesium Oxide (100) with 94 eV beam energy. | © Scienta Omicron
Magnesium Oxide (100) with 94 eV beam energy.

Drawings

Technical drawing of the Femto LEED  | © Scienta Omicron
Side view of femtoLEED DLD L800.
Technical drawing of FemtoLEED 8000 | © Scienta Omicron
Front view of femtoLEED DLD L800.

Configuration Guide and Specifications

The FemtoLEED DLD L800 optics is controlled using a LPS075-D power supply with a MCPS02 controller used to operate the microchannel plates. Integral shutter (model ISH-8) and LaB6 filament (model LaB6) are further options.

Specifications

Detector

Delay Line Detector with dynamic range 32 bit per channel, 75 microns spatial resolution and active area 145x145 mm

Acceptance angle

77° angle of acceptance from sample

Retarding Field Analyser

Concentric assembly of hemispherical grids

Working distance

15 mm from sample

Grid material

Gold coated tungsten wire mesh (100 mesh, 81 % transparency)

Energy Resolution

0.2 %

Monitoring

8" standard viewport

Linear motion

Up to 100 mm retraction from sample; linear ball bearing and acme thread with all spring electr. connections

Integral Shutter

Manual shutter driven by a rotary feedthrough

Magnetic shielding

Mu-metal cylinder with front cover for maximum attenuation

Assembly

Extreme-high-vacuum compatibility with stainless steel, high alumina and Au-plated copper alloy materials

Mounting

8"(CF150) double sided conflat flange with sample distance 145 mm – 400 mm

Bakeability

Under vacuum, 250 °C maximum

Integral Miniature Electron Gun

Beam energy system

LEED – 2 µA at 100 eV and 0.5 mm beam size

Beam size

From 1 mm to 250 µm - adjusted by Wehnelt potential, limited by exchangeable aperture down to 50 µm

Electron source

Tungsten-2 % thoriated filament standard, 
single crystal LaB6 filament optional

Energy spread

0.45 eV (thoriated - tungsten filament)

Overall size

10 mm lens diameter and 80 mm length

Microchannel Plates

Working area

75 mm

L/D ratio

40:1

Channel diameter

25 microns

Centre to centre spacing

32 microns

Plate thickness

1.0 mm

Bias angle