Standard Operating Procedure
MPB IN-100 CO2 Laser

 

MPB IN-100 Carbon-Dioxide Laser

Introduction

This Standard Operating procedure applies to the MPB IN-100 carbon-dioxide laser housed in Niagara College's High Power Laser Lab (V12).

Statistics

Manufacturer: MPB Technologies, Inc.
Type: Carbon-Dioxide
Class: IV
Maximum Rated Power (Original Factory Design): 200 Watts CW
Maximum Practical Power (Rebuilt Design): 50 Watts CW
Wavelength: 10.6μm
Cooling: Flowing Water, 0.5 gpm
Power Source: Single-Phase, 120V, 15A per phase
Amplifier Tubes: 2
Optics: OC - Flat ZnSe 85%R, HR - Silicon 5m Radius (99.8%R), Bending Mirrors (two) - flat silicon coated (99.5%R)

MPB IN-100 Controller
Front-panel controls

Operating Procedure

Revised 2012/01/06 by M. Csele

ALIGNING laser optics

  1. Turn the POWER key on the IN-100 control - located on the rear of the unit - and ensure the Emergency Stop button is pulled-out
  2. DO NOT turn the main power switch on.
  3. Switch the SHUTTER selector to EXT. This will open the shutter, allowing alignment of the laser optics, and will lock-out the high-voltage supply.
  4. Basic mirror alignment may then be completed using a low-power HeNe alignment beam
  5. When basic alignment is complete, place a power meter immediately in front of the IN-100 laser such that it will completely intercept the IN-100 output beam and rendering access to the output beam impossible.
  6. Ensure there are no objects in or near the inside of the laser (especially near the high-voltage electrodes on the plasma tubes). Proceed to start the laser as per the procedure below.
  7. With the plasma tubes energized, and the shutter open (part of the procedure below), proceed to "walk" the mirrors to optimize output power.

STARTING the laser

  1. Don safety glasses suitable for the infrared region around 10.6μm.
  2. Turn the cooling water supply ON. The valve is located behind the laser.
  3. Turn the POWER key on the IN-100 control - located on the rear of the unit - and ensure the Emergency Stop button is pulled-out.
  4. Switch the SHUTTER selector to INT.
  5. Ensure the INTERLOCK light is not illuminated. If it is, probable causes include a loose cover, insufficient water flow, or an external interlock jumper missing.
  6. If not previously refilled (procedure below under "GAS REFILL" section), verify that the tube pressure is within the range 1 to 10 torr via the pressure gauge on the RECHARGE MODULE. Avoid especially high pressures (> 20 torr).
  7. If the laser is opened for alignment or servicing, ensure that NOTHING is inside the cavity where it might (a) intercept the intra-cavity beam or (b) pose an electrical hazard by proximity to the front electrodes on the plasma tube - this area is clearly labelled "HIGH VOLTAGE".
  8. Turn the main power switch ON.
  9. The TUBE 1 OFF and TUBE 2 OFF indicators will light since the tubes are not energized at this point
  10. A ten second delay will begin after which the TUBE 1 ON and TUBE 2 ON indicators will light. At this point the plasma tubes are energized but the intra-cavity shutter is closed preventing lasing (The SHUTTER CLOSED indicator will also light).
  11. Pressing the SHUTTER OPEN button will open the shutter and lasing will begin. Laser operation can be toggled using the shutter control buttons.

SHUTDOWN

  1. Depress the SHUTTER CLOSE button. Lasing will cease immediately.
  2. Turn the main power OFF.
  3. Turn the key OFF.
  4. Turn the water OFF.

GAS REFILL

  1. Turn the main gas mix supply tank in the main V15 lab ON and divert the gas to the MPB laser via the valves on the low-pressure side of the gas regulator (This tank is shared between two lasers).
  2. Turn the RECHARGE MODULE Main Power ON.
  3. Turn the Vacuum pump ON and open valves V1, V2, and V3 to evacuate the laser tubes until the pressure gauge reads zero.
  4. Close V3 and momentarily press V4 to release a burst of gas into the laser tubes.
  5. Press V3 to raise the tube pressure, V4 to lower it. Approximate optimal pressure is 3 to 4 torr as read on the vacuum gauge on the unit.
  6. Close valves V1 and V2 to isolate the laser tubes.
  7. Turn OFF the vacuum pump as well as the Main Power to the RECHARGE UNIT.
  8. Turn off the main supply tank valve at the tank itself.
  9. Reset the Gas Fill Hour Meter via the switch on the rear of the unit
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