LEED 800 MCP  | © Scienta Omicron
LEED 800 MCP optics with retraction and shutter.
LEED 800 MCP  | © Scienta Omicron
LEED 800 MCP optics with retraction and shutter.
Digital LEED AES Controller Display Model LPS075-D | © Scienta Omicron
Model LPS075-D power supply for LEED operation.
Display of the LPS300 and LOA10-AES systems  | © Scienta Omicron
Model LPS300-D and LOA10-AES power supply for LEED and AES operation.
Microchannel plates power supply controller | © Scienta Omicron
Model MCPS1 power supply for microchannel plate operation.
Example screenshot of the LIM12 software that is compatible with the LEED 800 MCP | © Scienta Omicron
LIM12 Software.
Example graph from AES Software  | © Scienta Omicron
AES Software Images.
Screenshot showing element composition in the AES software  | © Scienta Omicron
AES Software Images.

LEED 800 MCP

LEED for Organic Films & Molecular Beam Epitaxy

LEED

  • High Image Sensitivity at the Primary Beam Current – 50 pA
  • Single/Dual 75 mm Microchannel Plates
  • AES at Beam Current 50 µA – 10 µA
  • Large Angle (101°) Fluorescent LEED Display and superior magnetic shielding
  • Miniature electron gun with large coherence width double focusing
  • Suitable for ESDIAD
  • Convenient LEED Image Capture with External CCD Camera
  • Simple and Powerful Operation with Digital Controller

The LEED 800 MCP with integral shutter has LEED and AES capabilities using a miniature electron gun, set of concentric grids and a conductive, phosphor coated screen. In addition, this optic model incorporates the high gain of microchannel plates.

It is an extremely reliable high-performance LEED instrument which operates with up to date digital power supply. The retraction mechanism has outstanding mechanical properties ensuring smooth day-to-day operation as experienced by our large user base over decades. The wide viewing angle (101° at 75 mm sample distance) and minimal shadowing of the screen by the miniature electron gun give a maximum visible LEED pattern.

More Information

Applications

LEED pattern of Germanium (100) with 120 eV beam energy. | © Scienta Omicron
LEED pattern of Germanium (100) with 120 eV beam energy.

The LEED 800 MCP is especially good at providing LEED and AES data of organic samples.  The larger size allows for higher angular and energy resolution and the gain from the MCPs allows better focusing of LEED imaging. 

LEED pattern of Gallium Nitride (0001) with 64 eV beam energy | © Scienta Omicron
LEED pattern of Gallium Nitride (0001) with 64 eV beam energy.
BP4 on Au (111) with 64 eV beam energy | © Scienta Omicron
BP4 on Au (111) with 64 eV beam energy.
BP3 on Au (111) with 69 eV beam energy | © Scienta Omicron
BP3 on Au (111) with 69 eV beam energy.
Graph showing the GaN - AES Spectrum  | © Scienta Omicron
Auger spectrum of Gallium Nitride.
Graph showing the Au AES Spectrum  | © Scienta Omicron
Auger spectrum of Gold.

Drawings

Technical drawing of Scienta Omicron's LEED 800 MCP product with back, front and side views  | © Scienta Omicron
Side view of LEED 800 MCP (model BDL800IR-MCP) optic.

For seamless integration, 3D step files are available for all models. 

LMX length calculation for LEED 800 MCP (model BDL800IR-MCP):

FS = 158 mm + 2LMX – OV + WD; where FS is the flange to sample distance, LMX is the retraction distance, OV is the overlapping distance, WD is the working distance and the 158 mm value is a constant related to this optic model.

If the calculated FS value is longer than the actual port length a nipple adapter can be added as a spacer between the LEED optics and the UHV chamber. The nipple length can be calculated as follows:

NL = FS – PL; where NL is nipple length and PL is port length. 

Technical drawing of the LEED 800 MCP Front View  | © Scienta Omicron
Front view of the LEED 800 MCP (model BDL800IR-MCP) optic.
Technical drawing of the LEED 800 MCP Back View  | © Scienta Omicron
Rear view of the LEED 800 MCP (model BDL800IR-MCP) optic.
MCP800 Model Side View  | © Scienta Omicron
Side view of the LEED 800 MCP (model BDL800IR-MCP) optic.

Configuration Guide and Specifications

The LEED 800 MCP optics is controlled using either a LPS075-D or LPS300-D power supply. The LPS075-D is used to operate the optic in LEED mode only whereas the LPS300-D in conjunction with the LOA10-AES lock-in controller and AUS30 input coupler is used to operate the optics in LEED and AES modes. Integral shutter (model ISH-8) and LaB6 filament (model LaB6) are further options. The MCPS01/02 controllers are used for operation of the microchannel plates.

Specifications

Glass-display

Fused silica coated with indium-tin oxide conductive layer and P31 phosphor (ZnS:Ag:Cu-green, 525 nm wavelength)

Acceptance angle

101° angle of acceptance from sample at a distance of 75 mm

Retarding Field Analyser

Concentric assembly of hemispherical grids

Working distance

20 mm from sample

Grid material

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

Energy Resolution

0.2 % - 0.5 % at low modulation voltages

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 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, AES - up to 100 µA at 3 keV

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

Electron gain