Distant galaxy neutrino detection at the bottom of the ocean

[scicop]

In this week's Science there is an article regarding the deployment of Neutrino detectors at the bottom of the mediterranean ocean, by astronomers, with the aim of understanding cosmic-ray emission by other galaxies.

 

Apparently, the neutrino "telescopes" are very sensitive light detectors, that measure the light emmitted by neutrinos when they collide with atoms. According to the article, the detection of neutrinos requires not only complete darkness but also locations where background levels are extremely low, such as deep under water (a the bottom of various oceans) or in underground mines with mass of earth above. The astronomers can selectively choose which galaxies to study based on the geographic location of the detectors.

 

This is really the first time I've heard of physics-based studies of the "heavens" where the "telescopes" are placed way underground or a the bottom of our oceans. This is why I thought the article was interesting.

 

I'm not a physicist or an astronomer, thus I don't understand the implications of detecting neutrinos from far off galaxies or what the relationship of neutrinos are to cosmic rays..anyone want to enlighten me?

 

http://www.sciencemag.org/cgi/content/summary/312/5778/1305

[swansont]

This is really the first time I've heard of physics-based studies of the "heavens" where the "telescopes" are placed way underground or a the bottom of our oceans.

 

SNO (Sudbury Neutrino Observatory) and Super-Kamiokande (which had a stunning photomultiplier tube implosion pressure-wave chain-reaction in the fall of 2001; more) jump to mind, and there may be others I'm not recalling. These were/are observing solar neutrinos, IIRC, to figure out neutrino oscillation issue.

[scicop]

SNO (Sudbury Neutrino Observatory) and Super-Kamiokande (which had a stunning photomultiplier tube implosion pressure-wave chain-reaction in the fall of 2001; more[/url']) jump to mind, and there may be others I'm not recalling. These were/are observing solar neutrinos, IIRC, to figure out neutrino oscillation issue.

 

Awesome, thanks for the great links. Very fascinating field, my interest has been perked.

[Martin]

some pictures of IceCube

http://math.ucr.edu/home/baez/week232.html

 

a cubic kilometer of Antarctic deep ice

to be equipped with detectors to pick up Cerenkov radiation

produced by neutrinos

 

http://icecube.wisc.edu/brochure/

 

IceCube encompasses a smaller detector Amanda which has

already been in operation for some time

 

there are a lot of neutrino detectors around the world for doing

neutrino astronomy----the ones Swansont mentioned, and the Antarctic ones, are I think especially famous and beautiful

 

a search would probably turn up several more, and tell you about the history which goes back several decades already

 

I think the first one was operated starting 1965 in Homestake Mine, an abandoned gold mine in some western US state. It found only 1/3 as many solar neutrinos as was calculated should be to give the observed solar energy output. Raymond Davis got the Nobel for that. here are some old pictures of neutrino astronomy circa 1960s

http://www.sas.upenn.edu/home/news/davispics.html

 

"... The AMANDA detector,buried 1500 meters beneath the South Pole, consists of more than 700 sensors arranged in a cylinder 1000 meters tall and 200 meters in diameter. The Eiffel tower is shown to illustrate the scale. ..."

[timo]

Just to add: It´s not only cosmic neutrinos for which one goes underground for measuring them. Some attempts to find WIMPs (= weakly interacting massive particles, a new fundamental particle proposed by some exotic physics scenarios and a potential candidate for being dark matter) exerimentally also benefit from being placed underground to reduce background radiation.

 

Seeing that Swansont and Martin both gave some links I don´t want to look cheap so I dug out at least one (not the experiment I was actually looking for but a similiar one) : http://edelweiss.in2p3.fr/index_newe.html

 

EDIT: They also link to the other experiments on above site: http://edelweiss.in2p3.fr/pub/fichiers/autres.html . I was initially looking for CDMS as I´ve heard a few talks about it, lately.