Ulvac EGL-206M Instruction Manual page 32

High voltage ( kV )
Set the X-axis magnet coil current to zero.
1. Before applying a current to the deflection coil, feed cooling water to the
hearth to prevent temperature rise of the coil.
2. Avoid continuous run with the X-axis magnet coil energized with a
current of 2.5 A or more, if possible.
(5) Apply a high voltage to the electron beam gun.
When the evaporant is a metal, a higher voltage of 7 to 10 kV is required;
when the evaporant is a compound, 8 kV or lower voltage is suitable. On
application of a high voltage, abnormal local discharge may occur, but it
should decrease gradually.
The ULVAC electron beam gun power supply is so designed that it
automatically lowers the high voltage if an overcurrent is produced due to
discharge, and the high voltage is restored after the discharge has ceased. If
the discharge does not stop, the possible cause is inside the vacuum chamber.
So switch off the power and check the electron beam gun, filament cables and
terminals of the high voltage feedthrough for insulation.
The voltage applied in the EB gun is enough to give danger to a human life. If
you touch the EB GUN or a surrounding of the EB GUN, turn off the main
breaker of the EB power supply and leave it for 5 minutes or more.
If the evaporant is magnetic material, a beam irradiation raises the
temperature and so magnetism is decreased. Decrease of the magnetism
affects the deflection magnetic field and position of beam spot is moved. So
adjustment of the beam position is needed.
SECTION 4
Current of X-axis magnet coil ( A )
10
8
6
4
CAUTION
1.75
1.4
1.1
0.9
NOTE
DANGER
22