An automated system for sample exchange and tracking in a cryogenic environment and under remote computer control was developed. Up to 24 sample “cans” per cycle can be inserted and retrieved in a programed sequence. A video camera acquires a unique identification marked on the sample can to provide a record of the sequence. All operations are coordinated via a LABVIEW™ program that can be operated locally or over a network. The samples are contained in vanadium cans of 610mm in diameter and equipped with a hermetically sealed lid that interfaces with the sample handler. The system uses a closed-cycle refrigerator (CCR) for cooling. The sample was delivered to a precooling location that was at a temperature of 25K, after several minutes, it was moved onto a “landing pad” at 10K that locates the sample in the probe beam. After the sample was released onto the landing pad, the sample handler was retracted. Reading the sample identification and the exchange operation takes approximately 2min. The time to cool the sample from ambient temperature to 10K was approximately 7min including precooling time. The cooling time increases to approximately 12min if precooling is not used. Small differences in cooling rate were observed between sample materials and for different sample can sizes. Filling the sample well and the sample can with low pressure helium is essential to provide heat transfer and to achieve useful cooling rates. A resistive heating coil can be used to offset the refrigeration so that temperatures up to 350K can be accessed and controlled using a proportional-integral-derivative control loop. The time for the landing pad to cool to 10K after it has been heated to 240K was approximately 20min.

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