2
Functional Description
Mass Spectrometer
44
TSQ Quantum XLS and TSQ Quantum GC User Guide
Thermo Scientific
Turbomolecular Pump
A Leybold TW220/150/15S double-inlet turbomolecular pump provides the vacuum for the
ion source, Q0 quadrupole region, and analyzer region of the vacuum manifold. The
turbomolecular pump mounts onto the top of the vacuum manifold (
The turbomolecular pump has two pumping inlets:
• A high-vacuum inlet at the top of the rotor stack, which evacuates the analyzer chamber
• An interstage inlet about halfway down the rotor stack, which evacuates the ion source
and Q0 quadrupole chambers
The turbomolecular pump is controlled by a Leybold TDS controller and powered by a
+24 V dc (250 W) power supply. The mass spectrometer circuit breaker switch and the
vacuum service switch, but not the electronics service switch, turn power for the
turbomolecular pump off and on. A fan draws air in from the front of the instrument cools
the pump.
Power to the turbomolecular pump shuts off if the foreline pressure, as measured by the
Convectron gauge, is too high, or if the turbomolecular temperature is too high.
Forepump
An Edwards E2M30 forepump
(or roughing pump) establishes the vacuum necessary for the
proper operation of the turbomolecular pump. The forepump also evacuates the inlet valve
and the collision cell. The pump has a maximum displacement of 650 L/min and maintains a
minimum pressure of approximately 1 Pa (0.01 Torr).
The forepump is connected to the turbomolecular pump by a section of reinforced PVC
tubing. The power cord of the forepump is plugged into the outlet labeled
Forepump
on the
power panel (see
on
). This outlet supplies power to the pump and is
controlled by the main power circuit breaker switch and vacuum service switch, not by the
electronics service switch.
CAUTION
Always plug the forepump power cord into the outlets labeled
Forepump
on the
right side power panel of the mass spectrometer. Never plug it directly into a wall outlet.
