Chapter V – Troubleshooting
5-27
C
996-0255 rev. b
19) Reconnect power to amplifier capacitor bank:
a. Turn off rack main breaker located on front right
hand corner.
b. At rear of rack replace cover plates.
c. Reconnect at rear of capacitor bank the high voltage
BNC that runs from power unit to capacitor bank.
20) Amplifier alignment is now complete. Replace all covers
and lids that were removed, log work done and proceed
with normal operation.
L. Flashlamp voltage adjustment
Equipment needed:
• power meter
• IR card
It is common for flashlamps to last 20-30 million shots. But during that
time the efficiency of the lamps will decline. It is possible initially to
compensate for the decline by increasing pump voltage. However, after a
point the thermal loading on the YAG rod becomes too great. At that
point the flashlamp should be replaced.
1) Before increasing pump voltage to bring laser output back
to spec, make sure that your power decrease is not due to
misalignment or optical damage.
2) Position power meter to monitor IR energy.
3) Increase pump voltage on power unit by 20 V.
4) Check free-running buffer. It must be at least 100 V. See
procedure page 5-18.
5) Open the intracavity shutter, allow the laser to Q-switch
and measure the energy.
6) Compare the energy reading to the original installation
energy.
7) If still below specs, repeat steps 3 thru 6.
If total voltage increases exceed installed voltage by more
than 100 V, then the flashlamps should be replaced.