Control Instrumentation for Advanced Adiabatic Demagnetization Refrigerators

Driven by research and development of advanced photon detectors--which require temperatures below 100mK-- there is considerable research into new ADR designs and techniques. These AADR have many advantages over other technique to achieve ultra-low temperature and there is considerable commercial potential. We propose to design control instrumentation for advanced adiabatic demagnetization refrigerators (AADR). The first step is to develop a thermal and electrical model of the basic operating parameters of various AADR. The next step is to split the design into hardware development and software development. Hardware development will take the results of the thermal-electrical model and design a circuit. This involves trade studies of different methods to measure and control temperature, magnets and heat switches. The software design focuses on optimizing the control of the multiple ADR stages and their timing sequence. This work will result in a control program and hardware design, which will be integrated together in Phase II