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The fast+slow pre-cooling allows us to reduce the slow pre-cooling time by initially fast pre-cooling the first part of the transfer line and then transition transit to the slow pre-cooling. Figure 2 (right) shows an example of the Tank T behavior of a slow pre-cooling that followed a fast pre-cooling. It is observed that the Tank T temperatures temperature drops significantly faster when a fast pre-cooling is initially preformed performed reducing the slow precooling time to about 1 to 2 hours. This This initial fast pre-cooling consumes 4 additional litters liters of LHe on the Liquifier.
Figure 2: Tank T temperature behavior for slow pre-cooling (left) and fast+slow precooling (right) procedures.
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