1. Rigidly bolt the system to the optical table using all available mounting locations in the
baseplate.
2. Ensure all screws inside the sample space are tightened down.
3. Ensure that the red shipping rings and spacers beneath the shipping rings have been removed.
The red shipping supports at the back of the cryostat should be locked in the upper position off
the tri-flange. See Removing the Shipping Supports on page 29 for details. Having any of these
components installed can introduce vibrations on the order of several microns.
4. Ensure the helium hoses are not touching other cabling or the optical table. They should also
not be pressed against a wall or another surface. There should be a gentle 180° bend in the
hoses to avoid any lateral tugging on the cryostat as helium runs through them.
5. Ensure the vacuum hose is not in contact with anything moving, as this hose is somewhat
springy.
6. Vibrational performance will vary depending on the operating speed of the
compressor/cryocooler. Vibrations are minimized when the compressor is running at a speed of
22 Hz/50 Hz, which is used during stable conditions at platform temperatures <20 K. See
Variable Speed Operating Parameters on page 51 for details.
7. Ensure that optics are rigidly mounted to the table. Optics could be vibrating due to the cryostat
on the table and mounting them should be carefully considered to reduce this effect.
7.3.3 Vacuum Check
The UI displays a pressure reading for the attached vacuum gauge sensor. If a system leak check fails, or
if condensation or freezing is observed on or inside the chamber, a leak may be present. Please check
the following:
1. Check to ensure the vacuum gauge properly reads atmosphere (~600-770 Torr) when the
system is at room temperature and vented. If it is not, the gauge may not be working properly.
2. Check that the vacuum housing and lid are in place and properly seated. Ensure no wires are
pinched between the O-rings.
3. Check the O-rings on the 1) the sample chamber vacuum housing 2) the vacuum housing lid
and 3) the vacuum housing outer “warm” windows. Ensure the O-rings have a thin layer of L-
grease and are completely free of debris or fibers.
a. All side panels also have an O-ring interface. Do NOT remove the side panels before
consulting with an authorized service representative.
4. For the Cryostation s50 model, ensure the black Delrin screws holding the sample PCB board in
place are loose. If overtightened, these can cause the board to flex and compromise the O-ring
seal.
5. Although nitrogen is optional, it helps keep the charcoal adsorbers clean and the inside of the
cryostat free from moisture. Using nitrogen is particularly important in humid environments.
a. Nitrogen purge cycles, as well as a platform bakeout, will help rid the chamber of
contaminants prior to cooldown.
To Next Page
Loading...