Pump Used In Presence Of Magnetic Fields; Accessories And Spare Parts - Varian TV 301 Manual De Instrucciones

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 special-
ist. As a matter of fact, in case of high magnetic
fields, also important forces might be generated
and applied to the rotor.
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47
TECHNICAL INFORMATION

ACCESSORIES AND SPARE PARTS

DESCRIPTION
Mains cable NEMA Plug, 3m long
Mains cable European Plug, 3m
long
Serial cable and Navigator
Software
Inlet screen, ISO 100
Inlet screen, ISO 160
Heater band, 120 V
Heater band, 220 V
Water cooling kit
Plastic water cooling kit
Air cooling kit for Navigator
Controller
Fan extension cable
Bracket for Navigator Controller side
mounting
Vibration isolator, ISO 100
Vibration isolator, CF 6"
Vibration isolator, ISO 160
Vibration isolator, CF 8"
Vent flange, NW 10 KF / M8
Vent device with adjustable delay
time for standard rack controller
Vent valve for standard rack control-
ler
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
Foreline flange KF25 1/4 gas
Forepump DS 302, with 1 ph.,
universal motor
Forepump MD 60, 120 V
Forepump MD 60, 220 V
PART NUMBER
969-9958
969-9957
969-9883
969-9302
969-9303
969-9804
969-9803
969-9337
969-9347
969-9299
969-9949
969-9349
969-9344
969-9334
969-9345
969-9335
969-9108
969-9831
969-9843
969-9834
969-9239
969-9240
969-9241
969-9242
969-9130
949-9325
949-9411
949-9412
87-900-946-01(B)