Following an RFP from the CSA for Canadian participation in the ESA Cosmic Vision proposals (9F007-2007/COSMICVISION), Dr. David Naylor submitted a proposal entitled "Canadian participation in the European Instrument (ESI) on the JAXA SPICA mission", and was subsequently granted the contract. (In January 2008 the ESI instrument was renamed SAFARI.)
During the initial phase of the contract, we have tested 2 of the primary candidate detector types for SAFARI and interfaced these with a room temperature Mach Zehnder Fourier transform spectrometer. In addition we have developed a SAFARI software simulator capable of predicting the performance of any proposed SAFARI instrument design.
The second phase of Canada's contribution to the SAFARI instrument development is the development of a cryogenic test facility to test materials, optics, mechanisms and position metrology techniques relevant to interferometer delay lines, at cryogenic temperatures. Our group's combined expertise in Fourier Transform Spectroscopy and cryogenic instrumentation is key to this activity.
We have designed, assembled and verified a new cryogenic test facility capable of cooling a ~0.05 m3 volume to 4K. This volume is large enough to house a basic interferometer of the type that will be used by SAFARI. Cryogen-free cooling to 4K is achieved with dual 1.5W closed cycle pulse tube coolers. A liquid nitrogen pre-cool system is included to reduce cool down periods if necessary. A He-10 refrigerator is available on the 4K stage to allow bolometer detectors to be operated inside the cryostat at ~0.3K. A wishbone arm interferometer delay line mechanism is currently being evaluated in the test facility.
A far infrared (FIR) detector development programme was undertaken in our group in parallel with the cryogenic testing program. The detectors produced through this program, a collaboration with the Cardiff University and the University of Alberta's NanoFab facility, are sufficient for our testing but are not sensitive enough to be considered for flight. We believe that it is important for Canada to participate in FIR detector development as there are many applications of this technology beside astronomy (eg. medical, air security, climate etc.).
Please send any comments or questions to naylor(at)uleth.ca