Telemark ST Series - Standard Operation

ST Series Power Supply Instruction Manual STANDARD OPERATION
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any arcing that may occur in the vacuum chamber (this can be seen by instability of the
HV meter reading or flashing of the “REG” LED).
When HV is stable at source operational voltage, leave potentiometer in this position,
this HV level is appropriate for most e-beam applications. Should a lower HV level be
desired (e.g. for dielectric materials), turn down potentiometer to reduce HV to that
level.
Turn off HV.
Set the “DSP SEL” (Display Select) toggle switch next to the Source LCD meter to “FIL”
(Filament).
Turn on the Source by pressing the green ON push button, this will light up, indicating
that power is supplied to the filament. After a several seconds the Source meter will
read a stable bias (preheat) filament current of around 18A. (The meter reads Amps in
the Filament mode)
Wait for about 15 to 30 seconds (to allow for filament preheating).
NOTE: A good range for setting the bias for Telemark sources is
between 17 to 21A, settings for other sources need to be determined by
trial and error (yellow glow of the filament, but still a few amps below
emission point) but should be very similar.
Turn on HV.
Flip “DSP SEL” toggle switch to “EMIS” (Emission), slowly turn up the “EMISSION”
potentiometer, watching the Source meter (reads mA in the Emission mode), until a
beam spot is visible in the crucible pocket. Check for correct position of the beam in the
pocket, then bring up emission further to heat the material to evaporation point.
Turn down the “EMISSION” potentiometer to zero, then turn off the Source and HV.
This completes the initial test of the power supply.
Turn off the front panel main breaker of the HVPS.
The power supply is now ready for use.
4.3.2 Standard Operation
When operating the power supply, it is considered good practice to first turn on the
source filament (Source ON) and allow it to heat up to preheat level (bias) for at least 15
to 30 seconds, and only then to turn on High Voltage (HV ON).