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New Mexico State University
College of Arts and Sciences
Department of Chemistry and Biochemistry
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Relationships Between Magnet Depth(cm) and Volume (L)

Parameter

Gemini 200

VNMRJ 300

Unity 400

Unity 500
Maximum Volume Liquid Helium, L
 28 29 65 70
Maximum Helium Can Depth, cm
 40 34 72 92
Average Full Levels for Helium, cm
 35 34 69 94
Average Levels @ refill for Helium, cm
 15 20 58 73
Average Volume Used in He Refills, L
 8 17 22 29
 
Maximum Volume LN2, L 35 35 75 95
Maximum LN2 Can Depth, cm 26 25 75 92
Average Full Level for LN2, cm 21 35 65 94
Average Levels @ refill for LN2, cm 10 13 55 72
Average Volume Used in LN2 Refills, L 21 20 20 20

An average of 76 L of liquid helium is required to completely fill all magnets every 5-6 weeks. The cost for a 100 L of liquid helium has increased from $588 to $667 to $827. A liquid helium Dewar must be about 85% full to successfully fill all magnets.

A single 230 L Dewar of liquid helium has the capacity to completly fill all magnets once a week for two weeks.

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