Recondensing superconducting magnet systems use a 4.2K cryocooler to recondense liquid helium boiloff during static (persistent mode) operation. Depending upon the particular system design and the customer’s planned use schedule, the 4.2K cryocooler can completely stop liquid helium boiloff and result in a zero loss system.
4T Ion-Trap Recondensing System |
Recondensing systems are
usually designed with a small amount of stored liquid helium. This results in a more compact design as compared to traditional superconducting magnet systems.
In all recondensing superconducting magnet systems, Cryomagnetics proprietary high temperature superconductor current leads are installed to minimize liquid helium usage. Cryomagnetics’ high temperature current leads are proven performers and have been used in many superconducting magnet systems over the years.
Always designed with safety
in mind, all recondensing systems are designed
to ASME code and manufactured in Cryomagnetics'
facility under strict quality procedures.
All recondensing
systems are equipped with Cryomagnetics
exclusive HRC-100 Helium Reliquefier Control
System. The HRC-100 is designed to
control liquefying rate by constantly monitoring
pressure in the superconducting magnet system’s
helium chamber. Positive pressure will always be
present within the helium chamber, thereby
reducing the risk of ice formation. Features a
digital display and easy integration in existing
superconducting magnet systems.
As with traditional liquid helium based superconducting magnet systems,
recondensing systems are available with a variety of thermal radiation shielding options. Intermediate thermal radiation shielding using liquid nitrogen is available, or designs with multiple thermal radiation shields without the use of liquid nitrogen are available. Experiments that require elevated temperatures in the room temperature bore can be accommodated as well as other special conditions.
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Another very important factor to consider when deciding between a liquid cryogen free or a liquid helium based system is how the design addresses power outages and superconducting magnet quenches.
In the event of a power outage or cryocooler failure in a
recondensing system, the liquid helium buffer will allow enough time for a safe discharge of the superconducting magnet without quench.
In a liquid cryogen free only system, the time between loss of cooling power and temperature rise above 4.2K is a matter of minutes, not allowing enough time for the safe discharge of the superconducting magnet.
The recondensing system can be viewed as having the best of both liquid cryogen free and liquid helium based systems—liquid helium costs are minimized, systems can be made smaller, and they have the ability to tolerant power faults without superconducting magnet quenches.
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Cutaway View of 4T Ion-Trap Recondensing System |
 Beamline Recondensing System |
 9.4 tesla, Actively-shielded Recondensing System |
 6T Ion-Trap Recondensing System |
High Field Vertical ICR Recondensing System
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Example 14T Recondensing System Quotation (presently
under construction)
Use this example to help define your specific
needs...
Superconducting
Magnet
Custom design solenoid configuration.
14 Tesla central field (4.2K).
High resistance persistent mode switch installed.
Fully protected against damage due to quench.
One (1) ruthenium oxide temperature installed to monitor
temperature during operation.
Recondensing Dewar
4.2K
pulse-tube cryocooler to reduce or stop liquid helium
boil off.
Vertical room temperature bore.
Welded aluminum construction.
Room temperature bore diameter: 127mm (5.00 inches) I.D.
Liquid helium boil off rate: Zero in static mode
No liquid nitrogen required.
Redundant liquid helium level sensors installed.
LN2 precool/removal tube.
Safety sealed quench relief system.
Vacuum space safety drop out plate.
15 foot long instrumentation cabling.
One (1) ruthenium oxide temperature installed on the
thermal radiation shield to monitor temperature during
operation.
Cryocooler Specifications
1.0W @ 4.2K pulse tube cryocooler.
Water cooled compressor.
One (1) ruthenium oxide temperature installed on the 1st
stage of the cold head to monitor temperature during
operation.
One (1) ruthenium oxide temperature sensor installed on
the 2nd stage of the cold head to monitor temperature
during operation.
The compressor service interval is 15,000 hours. This is
a simple adsorber replacement.
Model LM-500 Liquid Helium Level
Monitor
Set up as a single-channel instrument monitoring liquid
helium level.
Bright vacuum fluorescent display.
Simple, intuitive user interface.
Sample and hold operation (1 minute to 99 hours
settability).
Manual update or continuous operation.
Sensor de-ice cycle. (LHe only)
Adjustable constant current source.
Sensor calibration via front panel menu.
Can drive sensors up to 200cm active.
High and low setpoint control output.
RS-232 interface.
Option 3: IEEE-488.2 Interface.
Option 4: 19” Rack mountable case.
LabVIEW® drivers available.
Model TM-600 Temperature Monitor
Used to monitor cryocooler, shield, and superconducting
magnet temperatures.
Set up as a dual channel instrument (Option 3 installed)
to simultaneously monitor two temperature sensors.
CE-Marked.
Bright, two line vacuum fluorescent display.
RS-232 computer interface.
Option 2: IEEE-488.2 Computer Interface installed.
Temperature displayed in Kelvin, Celsius, Fahrenheit, or
expressed as a resistance.
Audible alarm (can be silenced).
Control output with high and low setpoints.
Simple keypad with good tactile response.
19” Rack Mountable Cabinet
LabVIEW® drivers available at no extra charge.
Model 4G-100 Integrated
Superconducting Magnet Power System
The Model 4G-100 is a single output model with output
current up to ± 100 amperes at 800 watts (± 10 volts up
to 80 amperes, ± 8 volts at 100 amperes).
CE-Marked
4-quadrant, true bipolar systems featuring smooth sweeps
through zero.
Automatic quench detection and protection.
A full color, backlit TFT liquid crystal display clearly
indicates output current, voltage, limit settings, and
system status.
Current settability of 0.1 milliamps
Five (5) programmable sweep rate ranges.
Persistent switch heater power supply.
15 foot length output cables.
USB, IEEE-488.2, and Ethernet computer interfaces
standard.
Safety interlocks for persistent switch enable/disable
and changing of important magnet parameters and limits.
Visual confirmation of current present in leads will
alert users to be mindful of safety when operating the
power supply, even if line power is off.
Instrumentation Cabinet
Industry-standard 19” inside width.
Prewired to house all instrumentation quoted.
Please click on the following
links for more information:
Please Contact Cryomagnetics at sales@cryomagnetics.com or your local Sales Representative for a price quotation.
Cryomagnetics offers online ordering
for electronic instrumentation:
and cryogenic accessories:
