PUMP USED IN PRESENCE OF MAGNETIC
FIELDS
Magnetic fields induce eddy currents in the rotor of
a turbomolecular pump that tend to oppose to its
rotation.
The result is increased electrical power consump-
tion by the motor, most of which is dissipated in
the rotor.
Since the rotor is not in contact with the stator the
above power can leave the rotor mainly by radia-
tion and hence the rotor may be overheated while
static parts of the pump remain cool.
This effect is strongly dependant from the inten-
sity, time function and distribution of the magnetic
field.
In general, therefore, an increase in pump current
can be expected.
If this increase is lower than 50% of the current
value drawn by the motor in high vacuum opera-
tion, no particular problem should be expected.
However if the effect is grater, than the case
should be carefully reviewed by Varian's specialist.
As a matter of fact, in case of high magnetic fields,
also important forces might be generated and ap-
plied to the rotor.
ACCESSORIES AND SPARE PARTS
DESCRIPTION
Mains cable NEMA Plug, 3m long
Mains cable European Plug, 3m long
Serial cable and Navigator Software
Bracket for controller side mounting
Inlet screen ISO 160
Inlet screen ISO 200 and CFF 10"
Inlet screen ISO 250
Heater band, 220 V
Heater band, 120 V
Water cooling kit (plastic model)
Water cooling kit (metallic model)
Air cooling kit for Navigator Controller
Air cooling kit for standard rack controller
Vibration isolator, ISO 160
Vibration isolator, ISO 200
Vibration isolator, CF 10"
Vent flange, NW 10 KF / M8
Vent device with adjustable delay time
for standard rack controller
Vent valve for standard rack controller
Vent valve for Navigator Controller
Purge valve with KF16 flange
Purge valve with 7/16" flange
Purge valve KF16-M12 20 SCCM
Purge valve 7/16-M12 20 SCCM
Forepump DS 402, with 1 ph. / 3 ph., uni-
versal motor
Triscroll Dry Vacuum Pump PTS 300 sin-
gle phase, universal motor
Triscroll Dry Vacuum Pump PTS 300 3
phase, universal motor
91
TECHNICAL INFORMATION
PART NUMBER
969-9958
969-9957
969-9883
969-9298
969-9304
969-9316
969-9350
969-9327
969-9317
969-9347
969-9337
969-9297
969-9315
969-9345
969-9346
969-9336
969-9108
969-9831
969-9843
969-9834
969-9239
969-9240
969-9241
969-9242
949-9382
PTS03001UNIV
PTS03003UNIV
87-900-945-01(G)