ocivm.com > LEED / AES Spectrometers > FemtoLEED DLD L800
Figure 2. LPS-D power supply for LEED & microchannel plate power supply MCPS01/02. 
Figure 4. Silicon (111) with 50 eV beam energy, 35 V GND. 
Figure 5. Silicon sample (185 deg) with 10 eV beam energy. 
Figure 6. Magnesium Oxide sample. 
Figure 7. Magnesium Oxide (100) with 94 eV beam energy. -94eV.jpg)
Collaboration with RoentDek in Germany.
The FemtoLEED 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.
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.
For seamless integration, 3D step files are available for all models.
For detailed specifications, download FemtoLEED 800 Configuration and Specifications (PDF).
| Optics | |
|---|---|
| Detector | Delay Line Detector with dynamic range 32 bit per channel, 75 microns spatial resolution and active area 145x145mm |
| Acceptance angle | 77 °C angle of acceptance from sample |
| Retarding Field Analyser | Concentric assembly of hemispherical grids |
| Working distance | 15mm 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 100mm 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 | CF8" (DN150CF) double sided conflat flange with sample distance 145mm – 400mm |
| 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 |
| 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 |
| Microchannel Plates | |
| Working area | 75mm |
| L/D ratio | 40:1 |
| Channel diameter | 25 microns |
| Center to center spacing | 32 microns |
| Plate thickness | 1.0mm |
| Bias angle | 8 ° |
| Electron gain | 107, operating in pulsed mode |
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.
For more information, download FemtoLEED 800 Configuration and Specifications (PDF).