Accurate Cryochamber For A Small Laboratory With Small Budget

Development of electronic devices for cryogenic temperatures requires specialized environmental chambers. The Microelectronics Research and Communications Institute required a low-cost alternative to the readily available environmental chambers. The solution was a simple aluminum cylinder cooled by pulsing liquid nitrogen into the cylinder to control the temperature of the electronics under test. National Instruments LabVIEW, GPIB communications, and simple bench top instruments control the temperature inside the chamber. This low-cost alternative will reach and sustain any set point temperature between room temperature and -190°C with an accuracy of ±5°C. Why Reinvent the Chamber? For NASA missions to the outer planets in the next two decades, reduced energy consumption means reduced payload. The development of electronics that operate at extremely cold temperatures ensure that they require less energy to keep the electronics warm enough to operate reliably. This technique reduces requirements for weight and volume of both the on-board power source and the insulation that encloses the experiments. It also helps the designers by placing the electronics closer to the sensors. In developing such low-temperature electronics, the University of Idaho’s Microelectronics and Communications Institute (MRCI) recognized a need for a low-cost, low-temperature test chamber. Such chambers can be quite costly, even for a temperature range that permits cooling with liquid nitrogen. The MRCI has not previously performed cryogenic testing for developing electronics. Cryogenic testing requires special procedures and equipment, as liquid nitrogen is hazardous and requires special handling precautions. The industry standard for cryogenic testing uses large and costly environmental chambers to perform electronics testing. The cost to implement a full environmental chamber can be in excess of $40,000 for a new liquid nitrogen cooled unit. In addition to the purchase cost of the unit, liquid nitrogen must be stored and transferred with special vacuum-insulated bottles and lines. The MRCI required a cheaper alternative to the commercial environmental chambers currently available.