Frequently asked questions
CryoProbe User Manual BRUKER 95 (107)
Is the CryoProbe performance stable and reproducible in the long
term?
Experience so far: Yes.
Will the CryoProbe be damaged if the cryocooling is accidentally
interrupted during a measurement?
An interrupt in the cryocooling should not break the CryoProbe.
Basic aspects C.3
Why does the CryoProbe have such a high signal-to-noise ratio?
Thermal noise is greatly reduced by cooling the NMR coil assembly and the
preamplifiers to cryogenic temperatures. Furthermore, the low electrical resis-
tance enhances the Q factor of all resonant circuits in the probe and its filters.
What is inside a CryoProbe?
The CryoProbe contains a tuned NMR coil assembly, a gradient coil, preamplifier
electronics, and supervisor electronics inside a vacuum isolated dewar. Cold heli-
um gas is circulated to cool the NMR coil assembly and the preamplifier electron-
ics while the sample is kept at ambient temperature. All the common probe
functions needed for RF transmission, tuning, gradient pulses, and VT gas duct
are built into the CryoProbe, while the sample lift and spinning are provided as
usual by the shim upper part.
What does the NMR coil look like?
The NMR coil assembly generates a transverse B
1
-field for the tuned frequencies.
Its material, geometry, and associated RF circuits are optimized for each type of
probe. Details of the coil assembly design are proprietary knowledge of B
RUKER.
What is the helium consumption of the CryoProbe System?
No liquid helium is used whatsoever. Helium gas (He) is needed for the initial fill of
the closed-loop system and for flushing the system before each cool-down. Dur-
ing cold operation, the He consumption is negligible. A standard He steel-cylinder
(50
) can last for more than 40 cool-down/warm-up cycles.
Can the user repair any part of the CryoProbe?
No, there are no user-serviceable parts on or inside a CryoProbe. Essential parts
of a CryoProbe may easily be broken during opening or closing. Therefore, ser-
vice actions on the CryoProbe can only be done at the factory. B
RUKER warranty
expires if the CryoProbe is opened by unauthorized personnel.
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