1. Building ICECUBE A Neutrino Telescope at the South Pole
Outline:
Neutrinos – What are they, where do they come from, what can they tell us
Neutrino Telescope – What it is, How it works
South Pole – Why at the south pole
Building IceCube – DOMs, Drilling Holes
Recent trip to the South Pole
Jeff Cherwinka
University of Wisconsin
Physical Sciences Lab
Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009

2. Briefly, what is IceCube?
A federally funded project administered through the National Science Foundation
We are in our 7th project year and will complete construction in 2011
We are building a Neutrino Telescope (a unique telescope) at the South Pole
Total budget for the project is ~$280M with all US funding managed at the University of Wisconsin
Here is the best part - on time, on budget, on schedule and …..it works!!!!
Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009

3. IceCube IceTop IceCube In-Ice Array Deep Core 1450 m 2450 m 2007-2008:
18 Strings :
13 Strings :
18+1 Strings
1 Gton of Ice
Transforming into a
Neutrino Teslescope :
8 Strings
1450 m
2450 m :
1 String
IceTop
Air shower detector
80 Stations (59 Operating)
4 DOMs in 2 Tanks / Station
AMANDA
19 Strings
677 Modules
IceCube In-Ice Array
80 Strings (58 Operating)
60 DOMs / String
17 m vertical spacing
125 m horizontal spacing
Deep Core
6 Strings (1 Operating)
60 DOMs / String
10 m vertical spacing
72 m horizontal spacing

4. Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009
What is a Neutrino?
Stable particle, but not part of Atom
No Charge, ½ integer Spin, Very very little Mass
Lepton Family:
Electon e-, Electon Neutrino e-
Muon , Muon Neutrino 
Tau , Tau Neutrino 
They do not interact much
There are a lot of them around
Beta Decay
of a Neutron
Most People are familiar with Protons, Electron and Neutrons because
Our world is made up of these particles… they interact with us
Neutrinos are also out there… but they do not interact much
Can travel through 100 light years of lead
Neutrinos are made in nuclear reactions such as when a Neutron changes into a Proton
Producing an electron and a anti electron neutrino in the process
Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009

5. Where do Neutrinos come from?
The Big Bang
 = 330 / cm3
E = eV
Source of  ’s
Where do Neutrinos come from?
Super Nova
SN1987
EMeV
The Sun e
Earth = 6 x 1010  / cm2s
E 0.1 – 20 MeV
Atmospheric ’s
e,,e,
1 /cm2s
E0.1– 100 GeV - -
Human Body
 = 340 x 106/day
The greek letter nu is use as the symbol for a neutrino
There are billions of neutrinos going through each of us every second
Most of these are produced in nuclear reaction in the sun
Neutrinos are also produced by radioactivity in the earth, and nuclear reactions in space
There are “manmade” neutrinos from nuclear power plants and particle accelerators
Some neutrinos interact in the atmosphere and create particle showers
The natural radioactive decay of potassium in our bodies produces 340 million neutrinos a day
Accelerators
E ~ 0.3 – 30 GeV
Nuclear Reactors
  few MeV
Earth’s Radioactivity
 6 x 106/cm2s
Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009
 = Neutrinos per time (Flux)  = Energy of Neutrino (1MeV = 1.6x10-13Joules)

6. Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009
Telescopes
Helps you see things more clearly by improving your power of “sight”
Traditional telescopes use visible light
We can also “see” in other frequencies: infrared, radio, X-ray
We can “see” with particles: Electron microscopes
Telescopes are directional
IceCube is a Neutrino Telescope
What does telescope mean?
Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009

7. Crab Nebula through different Telescopes
Visible
Infrared
X-rays
Neutrinos ?
Different ways of looking at something can give different information
The X-ray image show some structure in the nebula that the other images do not

8. Why a Neutrino Telescope?
Light does not go far
Absorbed and scattered by dust and gases
Interaction with microwave background
Charged particles do not go straight
Interaction with other matter
Bent by magnetic fields
Neutrinos can look places you can not see with light of charged particles
Neutrinos have little interaction ….they go far & straight ……..BUT they are hard to detect
Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009

9. Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009
What are we looking for?
Other detectors have seen evidence of VERY HIGH energy particles… Up to 100 EeV
Source is unknown
Air shower detectors have seen very high energy cosmic rays.
There are no known phenomena to explain energy levels as high as have been seen
Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009

10. Cosmic Accelerators LHC accelerates protons to 7 TeV
How do you make
particles with 100 EeV
(100,000,007,000,000,000,000)?
One idea is that these particles are made in cosmic accelerators
It take high fields and large distances to make high energy particles
Cosmic Accelerators

11. Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009
What are we looking for?
Dark Matter – WIMP Capture and Annihilation c
Earth
Sun nm
Many observations suggest there is a lot of matter
in the universe that does not produce light so we can not see it.
Other measurements suggest this dark matter is not made up
Of protons and neutrons like the “baryonic” matter we are used to.
One possible componet for this dark matter are particals named
Weakly Interacting Massive Particles WIMPs
WIMPs might be captured by the mass of the sun and interact there
Producing lots of medium energy neutrinos with more energy than the
Neutrinos produced by solar nuclear reactions
Detector
Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009

12. Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009
What are we looking for?
Super Nova SN1987A has already been seen!
Neutrinos escape supernova hours before light
Neutrino detectors have already seen Super Nova
More powerful detectors migth provide early detection of Super Nova
Allowing the scientific community to focus more instruments on
The early development of these cataclismic events
Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009

13. What Will We Find? Expect Surprises!
The most interesting thing we see is likely to be unexpected.
Everytime we look at the universe in a new way we are surprised
Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009

14. How do you “see” a Neutrino
You can detect a neutrino when it interacts and creates a charged particle
If the charged particle is traveling through a transparent material you can see the Cerenkov light it gives off
Neutrinos are hard to detect, but not impossible
You detect them indirectly by seeing the particles given off by an interaction
Wednesday Nite at the Lab – Jeff Cherwinka, April 8th, 2009