After unpacking and assembling the cryostat housing, it was hoisted in preparation for inserting the optics and insert from below (CC). |
Getting ready to lower the housing onto the optics/insert. Not a lot of clearance; note that the stool has been shortened (CC). |
Next came the first liquid helium fill...to cool things off a bit and check for leaks and other issues (CC). |
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On top of that and covering the telescope mount is this flexible blue environmental seal (CC). |
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19 December, time to install the cryostat into the telescope mount. First...Ki Won unhooks the hoses (CC). |
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Assembling the cryostat loading frame (CC). |
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Starting to hoist away...(CC). |
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The forebaffle installation was the last major visible bit of work on BICEP, but of course the setup and testing would continue...the first astronomical light was achieved on 15 January 2006 (on Eta Carina), and CMB mapping began a month later. After the first winter of operation, it was upgraded during the 2006-07 summer; it then remained cold and operated without interruption until the completion of operations in December 2008. (It was then upgraded to BICEP2 during the 2009-10 summer; this instrument was operated until December 2012). The above diagram is from the paper "CMB polarimetry with BICEP: instrument characterization, calibration, and performance" (2008) by Yuki Takahashi et al. Other relevant papers (also used for reference here) include "The Robinson Gravitational Wave Background Telescope (BICEP): a bolometric large angular scale CMB polarimeter" (2006) by Ki Won Yoon et al; and "Measurement of the Cosmic Microwave Background Polarization with the Bicep Telescope at the South Pole" (2010 PhD dissertation) by Yuki D. Takahashi. Here's the original project web site from Caltech, the prime collaborator, as well as a newer information page. Also of interest is this January 2007 Antarctic Sun article. Photo credits and thanks to: (YT) Yuki Takahashi (archive page); (CC) Hsin Cynthia Chiang; (KWY) Ki Won Yoon; (CW) Carlton Walker; (JK) John Kovac; (DB) Denis Barkats. Photos labeled (APL) are from the Antarctic Photo Library. Nearby, at the other end of DSL, the South Pole Telescope was starting to happen.... |