American Magnetics AMI Superconducting Magnets - Manual (Page 11)

10
Installation
Setup
Be careful not to disturb the wiring located on the top of the magnet. Only the
magnet current leads are to be bent and/or soldered.
2. Connect the magnet current leads to the superconducting bus bars or vapor-
cooled current leads if no bus bars are required. The magnet current lead and
bus bar connections are mechanically attached by wrapping the joint region
with a small diameter tinned copper wire. Electrical connections are
accomplished by soldered the joint region with ordinary eutectic lead-tin or
other low melting point solder.
Caution
Exercise care during the soldering process. A heat sink is recommended on
the magnet current lead close to the current lug to limit the heating of the lug.
Limit the amount of heat applied to the joint to allow the solder to flow
between the mating surfaces and not overheat the bus bar or leads.
Overheating of the bus bars could lead to delamination of the bus bar.
3. Refer to the persistent switch heater power supply manual and connect the
persistent switch heater, if applicable, to the power supply. Generally a top
plate connector is used to make this connection.
4. Use nylon cable ties as needed to support all wiring inside the dewar to limit
wire movement at very low temperatures.
5. Use a resistance meter to check the continuity of all wiring.
6. It is important for the user to know the level of liquid helium on the level
sensor when the magnet and switch (if applicable) are just covered. This level
will determine the minimum level of liquid helium required for safe magnet
operation. For AMI liquid helium level sensors, this distance is measured
from the bottom of the sensor to the top of the magnet and switch (if
applicable) minus 1/2 in. (1.3 cm). The included figure is provided to record
this information.
It is also important for the user to know the maximum level of liquid helium
which will be present in the system. This level is usually one inch (2.5 cm) to
two inches (5 cm) below the gas inlet holes at the bottom of the vapor-cooled
current leads. The included figure is provided to record this information.
Note
Refer to the operations manual of all system equipment and accessories
before connecting to the magnet system...
!