Carbon Evaporator Operation

Denton Vacuum DV-502

1. Open water supply and return lines on the wall. (You will need to turn on the cooling water for the vacuum annealing furnace as well as at the wall. This is hopefully temporary...)

2. Sign logbook.

3. Turn on the main power.

4. Turn on the mechanical vacuum pump.

5. Slowly open the Roughing Valve. After about a minute, open it to about 6 turns. Do Not open it fully.

6. Turn on the Thermocouple Gauge power.

7. After the bell jar has been pumped down to <100mtorr, close the Roughing Valve.

8. Slowly open the Backing Valve; open to about 6 turns. Again, do not open it fully.

9. Once the backing vacuum is below 100mtorr, turn on the Diffusion Pump power.

10. Wait at least 30 minutes for the diffusion pump to reach operational temperature.

11. After letting the diffusion pump warm up:

1. To Pump Down the Bell Jar -

   1. Close the Backing Valve;
   2. Open the Roughing Valve and wait until the bell jar pressure falls <<100mtorr;
   3. Close the Roughing Valve;
   4. Open the Backing Valve, and;
   5. Slowly open the 'Main Valve'.
      
      The system will now be pumping on the bell jar with the diffusion pump.

2. To Load a Sample -

   1. Close the 'Main Valve';
   2. Close the Roughing Valve;
   3. Open the Backing Valve;
   4. Open the Chamber Vent valve;
   5. After the bell jar is vented, remove it and place it aside upside down. Do not bump or touch anything to the boot.
   6. Load sample.
   7. Close the Chamber Vent valve.
   8. Replace the bell jar, and proceed to pump down the bell jar.
3. To Coat a Sample -

First, start up the evaporator vacuum system, then:

1. Prepare the material to be evaporated on to the sample. If it is carbon, then:

• • • Remove the old carbon rod from the evaporator head;
    • re-sharpen the rod and re-flatten the carbon anvil;
    • carefully replace sharpened and flattened carbon rod and anvil.

  • Load sample and pump down the bell jar to at least the 10-5 torr range.

  • Set the Filament Selector to the circuit that will be evaporating the material of choice.

  • Make sure the Filament Adjust is off (at zero).

  • Turn on the Filament Power.

  • Raise the Filament Adjust voltage until evaporation commences. (For carbon, DO NOT LOOK AT THE HEATED ROD. It will cause eye damage if viewed without welding goggles.)

  • Reduce Filament Adjust once there is a sufficient coating thickness.

  • Turn off the Filament Power.

  • Vent system following [B, then A]

  • Coat more samples if desired.
    
    

• Pump down the system following [B]
• Close the Main Valve
• Turn off the Diffusion Pump
• Wait 45(+) minutes for the diffusion pump to cool
• Close the Backing Valve
• Turn off the cooling water at the wall
• In the rapid succession:

Turn off the mechanical vacuum pump, and

...vent the M.P. Vent valve

• Sign out from the log book