document: Measuring and analysing the hold time of the CPA pill allows the thermal boundary resistance within the pill to be assessed; the thermal boundary dictates the actual temperature of the CPA crystals in comparison to the temperature of the cold finger, which is maintained at a constant temperature by a servo control program. Fig. 17 shows the temperature profile during the recycling of the CPA pill and subsequent operation at 200mK. During the hold time, the servo control program maintained the CPA pill temperature to within a millikelvin. It is expected that microkelvin stability can be achieved with fast read-out thermometry (which was not available at the time of testing but which will be used for the mKCC), as this would allow for temperature control on much faster (millisecond) timescales than the current (approximately 1s) thermometry readout used.
extractive_keyphrases: cold finger cpa crystals cpa pill microkelvin stability mkcc operation at 200mk pill recycling servo control program temperature thermal boundary
abstractive_keyphrases: fast read-out thermometry measuring and analysing the hold time of the cpa pill thermal boundary resistance