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INTEGRALEED Spectrometer

LEED 450 (model BDL450)

Miniature Instrument to Fit Any UHV System

The LEED 450 with integral shutter has LEED and AES capabilities using a miniature electron gun, set of concentric grids and a conductive, phosphor coated screen. It is an extremely reliable high-performance LEED instrument which operates with up to date digital power supply. The wide viewing angle (90° at 32mm sample distance) and minimal shadowing of the screen by the miniature electron gun give a maximum visible LEED pattern.


Features

  • Large Angle (90°) Fluorescent LEED Display and superior magnetic shielding
  • Miniature electron gun with large coherence width and dual lenses
  • Suitable for In Situ Film Growth Monitoring
  • Low outgassing rate
  • Convenient LEED Image Capture with External CCD Camera
  • Simple and Powerful Operation with Digital Controller

Applications

The LEED 450 is capable of providing LEED and AES data for a wide range of samples. The miniature size allows for integration into any UHV system.

Drawings

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

Outline of LEED 450 (model BDL450) optic.

External LMX length calculation for LEED 450 (model BDL450):
FS = OL + WD; where FS is the flange to sample distance, OL is the fixed optic length and WD is the working distance.

FS = PL + B + OV where PL is the port length, B is the minimum bellow length and OV is the overlapping value.

Front view of LEED 450 (model BDL450) optic.
Rear view of LEED 450 (model BDL450) optic.
LEED 450 Optic Layout.

Key Specifications

For detailed specifications, download LEED 450 Configuration & Specifications (PDF)

Optics
Glass-display  Fused silica coated with indium-tin oxide conductive layer and P31 phosphor (ZnS:Ag:Cu-green, 525 nm wavelength)
Acceptance angle 90 °C angle of acceptance from sample at a distance of 32mm
Retarding Field Analyser Concentric assembly of hemispherical grids
Working distance 10mm from sample
Grid material Gold coated tungsten wire mesh (100 mesh, 81% transparency)
Energy Resolution 0.8% at low modulation voltages
Monitoring 4.5" standard viewport
Linear motion External nipple with bellow up to 150mm retraction from sample
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 4.5"(CF63) double sided conflat flange with sample distance 145mm – 580mm
Bakeability Under vacuum, 250 °C maximum
Integral Miniature Electron Gun
Beam energy system LEED – 5 eV to 750 eV, AES – 5 eV to 3000eV
Beam current LEED – 2 µA at 100 eV and 0.5mm beam size, AES - up to 100 µA at 3 keV
Beam size from 1mm 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 10mm lens diameter and 80mm length

Configuration Guide

The LEED 450 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-45) and LaB6 filament (Model LaB6) are further options.

For more information, download LEED 450 Configuration & Specifications (PDF)

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