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Cryogenic Facility
There are two helium
refrigerators in B902: MAGCOOL-HEUB and PAT
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MAGCOOL-HEUB refrigerator |
MAGCOOL-HEUB is a CTI
Model 4000 refrigerator. It has two reciprocating expanders and has a
design capacity of 1500 W at 4.5 K. Together with a Model 1600 Wet Expander, MAGCOOL-HEUB is the primarily source of helium liquefaction in B902.
Maximum liquefaction is ~ 320 liter per hour using both expanders and
the wet expander. |
PAT control panel with PLC |
PAT helium refrigerator is designed and built by CVI corporation using two Air Liquide turbines. The design capacity is ~1000 W at 4.5 K. It was installed in
B902 for Production and Testing of magnets in 1979. For more than a decade, it
has performed reliably. Reliability of the turbines deteriorated in the late
90's. |
Air Liquide Turbine on PAT |
PAT was brought back to service with a major upgrade on instrumentation and
control of the turbines funded under a BNL GPP grant. The installation effort
took about one year. After test runs conducted in December 2003, PAT is used
routinely with a capacity of ~ 160 Liter per hour. |
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In the vertical test area,
there are five Test Dewars for testing superconducting magnets and cable samples
using pool boiling.
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Cable dewar 4 |
Test Dewar 2 and 3 are dedicated for testing magnets and are
6 m (20 foot) deep. The
inner diameter is 24 inch for dewar 2. Dewar 3 has an inner diameter of 28 inch
to accommodate larger magnets such as DX or LHC D2.
Test Dewar 4, 5 and 6 are mainly dedicated for testing cable samples
and are 2.7 m ( 9 foot) deep. The inner diameter is 24 inch. Dewar 4 and 6 are designed for 4.5 K operation. Dewar 5 can be operated
at either 4.5 or 1.8 K.
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In the horizontal area,
magnets are being tested using supercritical forced flow at 4.5 K.
There are five stands: Bay A, B, C, D
and E. Bay C has an added feature for
testing magnet in pool boiling. Presently,
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MAGCOOL test stand |
Bay A is used in
conjunction with helium liquefaction.
Bay B is not used.
Bay C is used
for testing LHC D2 magnet.
Bay D is
reserved for magnets similar to that for DESY upgrade.
Bay E is
reserved for RHIC magnet. |
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There are three liquid
helium storage:
Storage Dewar 1:
3,785 Liter (1,000 gallon)
Storage Dewar
2: 3,785 Liter (1,000 gallon)
Storage Dewar
3: 10,000 Liter (2,640 gallon, ~ 22 gal / in)
The liquid
nitrogen storage is 40,000 L.
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Gas recovery system:
Under construction
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$ and Cents
Per BNL Supply Material Division, price of liquid
helium is $ 3.25 per Liter in 2001 (in 60, 100, 250 or 500 L size). Delivery to
BNL is limited to Monday, Wednesday and Friday only. A $400 shipping charge
will be added if order is not placed in time.
“Liquid helium is cold (-269 degree Celsius
or 4.5 K) and expensive.”
In an emergency situation, the value of liquid helium
cannot be measured in dollars per liter. If a superconducting magnet runs
out of liquid helium (due to delivery problems, for example), testing delays and
the cost to re-cool the magnet will be significant. The Magnet Division
has been glad to help other on site users on a few occasions.
The price for a 50,000
cubic foot helium tube trailer is ~ $4,400 ($3,600 for gas plus $825 for
shipping). The price of “helium gas” per liter of “liquid helium” is ~ $2.44.
Compared with $3.25/L for liquid, the price difference between liquid and
gaseous helium is ~ $0.80. There is a strong incentive for gas recovery
provided that there is a good purification system.
Price of liquid nitrogen is ~ 6 cents per liter.
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Last update on:
February 22, 2008 by
D. McChesney. |
