Another SCUBA-2 Setback
- Thu Jul 3 2008
- Astronomy
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SCUBA-2, being a revolutionary instrument and all, is still in the process of being commissioned at JCMT. It shipped with “engineering-grade” arrays, which are of lower quality than “science-grade” arrays. They have more dead pixels and the remaining pixels are noisier than the requested spec. They can still be used for commissioning, as they can detect photons, only not well enough to do proper science with.
The science-grade arrays are still being manufactured in a rather long and complicated process, involving groups from the National Institute of Standards and Technology in Boulder, Colorado, the UK Astronomy Technology Centre and the Scottish Microelectronics Centre in Edinburgh, Scotland, the Astronomy Instrumentation Group at the Cardiff University in Wales, and of course the Joint Astronomy Centre in Hilo, Hawaii. Bits and pieces get flown all over the place, and it’s a wonder that nothing serious has happened to the arrays or any bits of them*.
Until June 9, when NIST researchers discovered that a vial of plutonium was cracked and some particles spilled from the vial. Understandably this has lead to the closure of the lab while cleanup and investigations are done. Unfortunately this lab had either parts of the arrays or the full arrays in it. They’re not expecting to get into the lab until August, when we find out if the radiation event caused any damage to the sensitive SCUBA-2 array electronics.
Since then, NIST has found that some of the plutonium entered the sanitary sewer system at levels below state and federal limits, and that some NIST employees show evidence of internal plutonium exposure. Obviously SCUBA-2 should take a back seat to more important concerns.
But full operation SCUBA-2 has just been pushed back again. How much is still uncertain, but a month is probably the lower limit.
*One of the more serious problems to date came when one of the groups was preparing the arrays for shipping and accidentally dropped a crate on or tightened a lid on one of them, crushing one of the corners. Whoops.
