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Measuring Base

A warm count rate can be taken at any temperature above 200mK.

To reach base, turn off all power to the MC heater. Leave about 4mW on the still heater.

Once the system has stabilized at base. Take a cold count rate (for each PMT). The ratio of the cold to warm count rates can be used to find the current temperature. The two PMTs should be in agreement.

To find the true base temperature, adjust the still heater until the lowest temperature is found. Record this value in the log book.

For a detailed guide on how to use the $ ^{60}$ Co Thermometer LabView program, see the manual.

Jonathan Ouellet 2014-08-26