Alas. The party's over. This is the end of Boomerang - face down on the
Antarctic plateau hundreds of miles from the south pole. But we have
our data, so may Boomerang rest in peace.
The last four years or so I've been working on the new technology which flew on
Boomerang in the 2002/2003 Austral Summer. We are now busy analyzing those
data. Someday I will start to write a thesis...
In addition to Boomerang, I've dabbled in both data analysis and
instrumentation for both
the Microwave Anisotropy Probe, back in Princeton, and for the Planck Surveyor here and at the
Jet Propulsion Laboratory. More specifically, I've worked on CBR anisotropy
data analysis techniques, including the removal of foreground and low frequency
noise contamination from the images. My senior thesis (for the Physics Department at Princeton) was a
verification of MAP's feed antenna design, including a comparison of
the measured radiation pattern and an analytic model to the -70 dB level.
You can get some notes on measuring feed antennas here. For Planck, I've done a
study of the effect of various scan strategies on the distribution of
integration time on the sky, and the ability to combat low frequency noise.
I've started to work on simulating time ordered data in a realistic way,
focusing on the issue of polarization. The scientific potential of CBR
polarization information is nearly as substantial as the experimental challenge
of measuring it. Both CBR anisotropy space observatories have a long way to
go before they'll be able to make quality polarization maps, but
Planck still has some time. You can get the latest (September 23,
1998) notes regarding Planck Surveyor's scan strategy and sky
coverage
here.
Below are simulations of integration time for the Planck Low
Frequency Instrument at 70 GHz. The results are not qualitatively different
for the 30,44, and 100 GHz channels. The clumping of integration time
evident in two of the images is a result of the low frequency (that is,
low compared to MAP, or the 1 rpm spin rate for that matter..)
wobbling of the spin axis which has been proposed. This effect can result
in narrow bands having as much as 4 times the sensitivity as the adjacent
strips, which is not so good for parameter estimation. The smooth image
is a simulation of a 90 degree spin-optical axis configuration, with no
wobbling.
I've also done some computational microwave modeling of Boomerang's reflector
system. Some of these results are avaliable here.
Currently I'm working on a new type of intrinsically polarization sensitive
bolometer, for use on Boomerang as well as the HFI aboard
Planck Surveyor. There are some animated gifs of the E field amplitude here.
The first of these have now flown on Boomerang, and they work great! A paper with more
technical details can be had in both postscript and pdf formats.
Click here to see pictures of the testbed and prototype, as well as some transmission spectra and polarization signals.
These devices should provide the sensitivity and low
susceptablilty to systematics required for precision polarimetry of the
microwave background. Once these things are up and running, we should detect
gravitational waves before LIGO! Well, ok, so maybe we won't see any gravitational waves, but neither will LIGO. heh heh.
 I've also got my hands in the cryogenic beast that is the Polatron, which is a
receiver to be installed on the 5 meter dish at the Owen's Valley Radio Observatory. We have put together a system which can, at the turn of a switch, cool our detectors to below 300mK with an approximately 75% duty cycle with no liquid cryogens. Yippie. Time for a beer.The Owens Valley is
a good place to observe from because it's really dry since we stole all their
water... Not that there is lingering bitterness about that.
Those are llamas there on the right.
They make good guard dogs.. er, llamas. Alpacas? Not so good. I don't know why.
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