Spider is a balloon-borne instrument designed to search for the signature of primordial gravity waves that is (hopefully) encoded in the polarization of the CMB. The design consists of six independent telescopes operating at three frequencies (100, 150, and 220GHz), with the optics cooled to 4 Kelvin and the bolometric detectors cooled to 0.25K.
Spider's first test flight will be in the fall of 2009, from Alice Springs, Australia. The test flight will be 2-4 nights duration, limited by the requirement that the balloon be brought down before it leaves the continent. The full "around the world" flight will be a year later, if all goes well.There are two publications describing Spider:
- "Spider Optimization: Probing the Systematics of a Large Scale B-Mode Experiment", C. J. MacTavish etal, arXiv:0710.0375, submitted to ApJ. (This discusses Spider's potential systematics and scan strategies).
- "SPIDER: a new balloon-borne experiment to measure CMB polarization on large angular scales", T. E. Montroy etal, Proceedings of the SPIE, ed L. M. Step, v 6267, p62670R, (2006). (This describes the Spider instrument as originally conceived.)
In addition to the effort at Case, the Spider collaboration includes groups at Caltech, JPL, U. Toronto, UBC, NIST, Cardiff, and the Imperial College of London. The main SPT website is maintained at Caltech, at http://www.astro.caltech.edu/~lgg/spider_front.htm.