Ulvac EGL-206M, Instruction Manual

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SECTION 3
8
3.2 Installation of Electron Beam Gun
Always observe the following precautions for safe operation of the electron
beam gun. Wear clean gloves when handling parts to be installed in the
vacuum chamber.
(1) Gun base
Use a SUS304 stainless steel gun base.
CAUTION
Weight of EGL-206M /EGL-406M is 18kg, so the gun base needs enough
strength to bear the weight. Special attention is needed in case of making
notches or holes.
If the exhaust port is located under the gun base, make a notch or a hole in the
gun base so that the pumping efficiency is not lowered.
(2) Installation of electron beam gun
The electron beam gun installation area must be wide enough to easily mount
and dismount the emitter assembly in maintenance. Install the electron
beam gun in a horizontal position and couple it with the hearth rotation
mechanism. The hearth drive shaft can be installed in one of three directions.
Since it is installed in the rear as standard, it will be necessary to disassemble
and reinstall it if installed on the right or left. Two-thirds turn of the drive
shaft moves one crucible.
The system is so designed that when the six crucibles have moved to their
positions, they are positioned with a feeling of click. If it is to be driven by
motor, install an electric circuit that stops motor rotation when the crucible
has moved to their positions. The revolution of the hearth drive shaft should
be 5 rpm less. The electron beam gun is the magnetic deflection type. If
there is any ferromagnetic material near the magnetic pole, the magnetic flux
will concentrate on the material, causing magnetic loss or disturbance of the
magnetic flux distribution. Under this condition, the beam spot will be
deformed or the beam position will deflect, making normal operation
impossible. A steel bell jar can cause such a trouble.