This file tells how to change an anode filament. It was last modified
 August 13, 1993 by SDK


1 Make sure anode is off (NOT the main power, just the regular tube
  voltage) and the chilled water exchanger can be turned off too.
2 Turn off main valve (MV) and Penning gauge (PG). Wait for sound of valve
  closing fully (a few moments).
3 Turn off VARIAN ion gauge.
3a Close flight path and chamber roughing valves at back.
4 Bleed top chamber (at front) [PG reads 415 Torr at atmos. press).
5 Unscrew front cover.
6 Loosen screws at filament housing bottom (inner screws) so screen falls 
  (don't take out)
7 Loosen connection screws on high voltage supply (formerly behind screen).
  (An english 3/32 wrench works).
  Grab clip while turning so as not to stress anything.
  These screws are not captive, but if careful, they will remain held
  to the high voltage cable ends. Pull these screws forward a little if
  they don't disengage from the housing.
8 Loosen outer bottom screws of filament housing and remove housing.
  Note that these screws are captive.
9 Cover opening to anode with Al foil while continuing.
10 Remove unit- open up, taking out large screws on back.
11 Take off filament undoing back screws (allen head ones).
12 Clean filament holder if necessary. Sand blast if necessary.
13 Clean filament holder in acetone ultrasonic rinse. Rinse in methanol.
14 Put in new filament very carefully. Check that the filament is centered 
   straight.
15 Screw on back.
16 Screw unit back into machine.
17 Screw in connections, ensuring wires are straight, not near housing.
18 Lift and screw on shield screen.
19 Close back of machine (check O ring fits evenly and tightly).
20 Rough down top unit using rotary pump. When at 200 millitorr (approx 1/2
   hour) close roughing valve.
21 Open main valve. Open PG
22 Turn on ion gauge.
23 Degas ion gauge.