PCB Blog - Reflection high energy electron diffractometer PCB board

This reflection high-energy electron diffractometer is developed by Shenzhen Century Core, which focuses on reverse research and development of PCB board, etc., on the basis of cracking the original prototype. Make corresponding design and functional parameter modification.

1. Electron gun part
The RHEED electron gun is an electron optical system specially designed for conducting diffraction studies with energies ranging from 10 to 30 keV. By combining electrostatic and magnetic components, the electron gun features high brightness, small speckles, low dispersion and extremely low outgassing rates. The electron gun can be completely installed outside the cavity, can be maintained in situ, and can be baked. It can also be used in high pressure environments if equipped with a differential extraction system.

2. Control Power Section
The compact design of the electron gun power control section that provides 30KeV energy is manufactured by the electronic components of . The setting parameters of the electron gun, such as energy, filament current, beam intensity, etc., can be displayed on the display in digital form, and the beam intensity, focus position, etc. can be adjusted remotely through a simple control panel. The system has self-diagnostic capabilities, which can quickly and comprehensively check the RHEED system.

3. Electron beam diaphragm
The beam current can be switched on and off via the electron beam diaphragm, which ensures an extremely low electron load on the sample. The aperture switch signal can also be triggered by an external signal at the same time, which allows the RHEED to be used in the presence of interfering magnetic fields and to study rotating samples.

4. Electron beam swing
For RHEED analysis, the electron beam must be incident on the sample at a grazing angle. The unique electron beam rocking feature allows adjustment and variation of the electron beam incidence angle without moving the sample. This feature is very useful when performing analytical tests on samples in fixed positions

5. Differential extraction system
Conventional electron guns are designed to work under higher pressure conditions such as 10-4 torr, but this inevitably results in a shortened filament life. The RHEED system with the option of a differential extraction system ensures routine operation in the presence of high pressure and reactive gases. Efficient extraction of the filament section gives the RHEED system unparalleled flexibility compared to other systems.

6. Computer Control
The RHEED system can be fully computer controlled. The electron gun control part includes an interface module and a software package, which ensures the flexibility and repeatability of the RHEED. The parameters set by the user can be saved and recalled, the on-off of the electron beam can be controlled by the electron beam aperture, and the incident angle of the electron beam can be adjusted by using the electron beam rocking feature.

7. Fluorescent screen
Screens are available in various sizes with very high spatial resolution and excellent contrast. The aluminized protective coating on the fluorescent screen ensures that the fluorescent screen has very good electrical contact characteristics, and can shield some free light from the vacuum chamber, thereby improving the contrast of the RHEED image.

8. Data acquisition and analysis system
RHEED Vision is a set of very powerful data acquisition software that can be used with various existing RHEED systems. It can perform image processing and real-time data analysis at the same time. And there are plenty of optional data reduction programs. In addition, other hardware control modules are also provided, such as phase-locked epitaxy growth, shutter control, laser pulse trigger on PCB board, etc.