The Fastest Way between Fermilab and Minnesota

1
The Fastest Way between Fermilab and Minnesota

• Deborah Harris
• Fermilab

2
Between Fermilab and Minnesota

• By Plane
• Flying there takes 3 hours plus airport security
  and traffic around OHare airport
• By Car
• Driving there takes 10 hours plus 15-minute stop
  to buy cheese in Wisconsin
• By Phone
• A Phone call must travel above the earth by
  satellite few hundredths of a second
• By Neutrino
• Travels 450 miles straight through the earth at
  99.999 the speed of light 1/400 of a second

3
What is a Neutrino?

• Breakfast Cereal
• Japanese rhythm and blues band
• Penny-sized jumping spider
• Tiny neutral particles that weigh almost nothing
  and almost never interact with anything else
• Answer most of the above

4
What do you mean they weigh almost nothing?

• Normal matter made of elements
• Elements made of protons and neutrons and
  electrons
• How much do neutrinos weigh?
• Protons and neutrons 1GeV (a trillion
  trillion or per gram)
• Electrons 2,000 per proton
• Neutrinos gt1,000,000 per electron

5
What do you mean they almost never interact?
n

• - n has a good chance of traveling
• thru 200 earths without interacting
• 100 billion neutrinos from the sun pass through
  your thumbnail every second and you dont even
  know it

• Good news and bad news
• We can send them long distances and they will go
  where we send them
• We have to send billions and billions of them
  through a huge detector before one of them will
  interact there

6
How can you see neutrinos?

• Indirectly by studying particles that decay
  (radioactivity)

Y'
Y
surprise!
7
Energy crisis

• Some famous physicists said
• Maybe energy is just not conserved, this quantum
  mechanics is stranger than we thought
• Wolfgang Pauli wrote (in famous desperate
  remedy letter)
• Maybe theres a neutral particle that lives in
  the nucleus that can take away some of this
  energy during a decay, we just dont see it
  because its neutral

Y'
Y
8
Enter Enrico Fermi

• Enrico Fermi introduced a new weak force to
  describe radioactive decay
• proposed a smaller neutral particle neutrino
  which is created through this weak force
• Paper rejected by Nature because it contained
  speculations too remote from reality to be of
  interest to the reader
• Thirty years laterneutrino is discovered at a
  nuclear reactor

n
p
9
What makes the sun shine?

• Since Newton, we have known roughly how much the
  sun weighs 2 million trillion trillion kilograms
  (2x1030kg)
• Since the development of fuel, we know how much
  energy you get from one gallon of fuel
• We know how much energy the sun produces in
  light, given how much we see
• This calculation says that the sun is 100 million
  years old
• We know the sun has been shining for at least 4
  billion yearshow can that be?

• Answer neutrinos and the weak interaction

10
Neutrinos from the Sun
11
Why else should we care about neutrinos and the
weak force?

• This is what allows nuclei to break up
• This is what allows different nuclei to come
  together
• If no weak force, then nothing more than
  hydrogen in the universe!

12
Beyond the periodic table

• More to the universe than whats in protons and
  neutrons

Charge
2/3
Quarks
-1/3
Proton uud Neutron udd
Leptons
-1
Neutrinos are what let neutrons decay to
protons or a d quark turn into a u quark
0
Mass
13
The Case of the Missing Neutrinos

• Neutrinos from the sun were first observed by the
  Homestake experiment over 30 years ago
• Only found 1/3 the number they expected
• A similar mystery was found with the atmospheric
  neutrinos
• 1/2 the number expected were observed
• Neutrino experiment at Los Alamos found five
  times as many electron-type neutrinos as
  expected(which could mean that 0.3 of the muon
  neutrinos changed)
• These signals could be explained if neutrinos
  have mass, and if different neutrinos have
  different masses

14
What are we doing with neutrinos at Fermilab?

• Now Studying how neutrinos change from one
  flavor to another
• MiniBooNE looking for muon neutrinos turning
  into electron neutrinos over short distances
  (Kane County)
• MINOS looking for muon neutrinos turning into
  anything but muon neutrinos between here and
  Minnesota

15
Why Minnesota?

• The state with the most saunas per capita in the
  US
• They have the best iron mines
• Measurements of neutrinos from atmosphere
• Neutrinos from above dont change flavors
• Neutrinos from below change a lot
• Neutrinos from the atmosphere have to travel at
  least a few hundred miles to change at all
• So we have to send a beam of neutrinos far
  enough through the earth so that they will
  have had at least that much time to interact

16
How can you make a beam of neutrinos?

• Like making a beam of light with a flashlight
• Start with a putting a current through a filament
• That makes light
• Focus the light through a lens
• One minor added complication protons dont make
  neutrinos, you have to make particles that decay
  to neutrinos

17
Booster
Main Injector
18
Beamline for MINOS
150 ft
350 ft
2000 ft

• MINOS doing everything that other neutrino beams
  do, but from 450 miles away and at a 3.5o angle
• Miners excavated a mile of underground tunnels
• Filled decay pipe region back up with concrete
  1000 cement trucks worth of cement
• Two elevators, two large halls
• Target hall filled with target, horns shielding
  blocks
• Near Detector Hall 150ft long, filled with
  MINOS Near detector
• 3½ year construction longer than MINOS has been
  taking data

Photo of Chris Laughton With Tunnel Boring
Machine
19
Image courtesy of Bartoszek Engineering.
MiniBooNE
These targets see 10s of trillions of
Particles How can you keep something cool when
you keep pumping energy into it? MiniBooNE
power xxxx kWatts MINOS power 200kWatts Hair
Dryer 150Watts
20

• MiniBooNE Horn
• Has pulsed 100 million times
• 5 times a second!
• MINOS Horns
• 10 million pulses
• Once every 2 seconds
• Horn Currents 200,000 Amps
• 200,000 toasters!

(sounds of horns)
21
(No Transcript)
22
Ode to those who put the protons right on target

• In order to make neutrinos, someone has to
  vigilantly watch over the protons as they are
  accelerated to high energies
• Direct them through the beamline
• Hit the target
• And never miss!
• Like walking a mile with a glass full of milk
  that you cannot spill
• Over and over and over again for years
• And what thanks do they get?

23
How many detectors are there?
MINOS trying to see how many muon neutrinos
DISAPPEAR (really just change
flavor) MiniBooNE trying to see how many
electron neutrinos APPEAR
24
How can you see a neutrino?

• These three neutrinos (ns) are associated with
  three charged particles, who are as different
  in size as
• Squirrel (e electron)
• Lion (m muon)
• Elephant (t tau)

You cant see the neutrino, but you can see their
partners
25
How can you see Neutrinos Directly?
n
p

• If radioactivity occurs, then this also happens

n
p

• Even more rare, neutrinos can hit electrons too

26
Measuring Neutrino Flavors

• You cant see neutrinos, but you can see what
  they produce when they hit protons and neutrons
• Problem you cant see these products with a
  microscope, because you need lots of protons and
  neutrons and microscopes are expensive
• How to tell the difference between flavors?

27
MINOS
MINOS Detector 5,400 tons of steel and plastic
Not just any plastic it gives off light when
charged particles go through it Collect the
light more particles, more light
28
Telling the lions from the squirrels

• These particles all had the same energy, so
  total light is about the same
• but pattern in the detector is very
  different

29
Neutrino Patterns in MINOS

• This one has a muon in it thats the only thing
  with charge that can travel through a few feet of
  steel!

• This one does not has a muon in it hard to tell
  in this detector between muons and anything else
  if many particles are produced

30
MiniBooNE Detector Technique

• Who here knows what a sonic boom is?
• The noise that gets made when something goes
  faster than sound
• Who has heard one?
• Airplanes
• Thunder
• When something goes faster than light, the same
  thing happens, only instead of a loud boom, you
  get a flash of light

31
MiniBooNE Detector

• tanks contains 250,000 gallons
• of mineral oil (neutrino target)
• - 44 tanker trucks worth!
• - 800 tons!
• lined w/ 1520 PHOTOTUBES
• (electronic eyes
• of the detector)

Phototubes work like inverse light bulbs -
produce an electrical signal whenever light
strikes them
32
Neutrino Patterns in MiniBooNE
muon
electron
33
How can neutrinos change flavors?

• Quantum mechanics presents us with a lot
• of phenomena that seem weird non-intuitive
• - neutrino oscillations is one of them
• - ns can shift their identity transform
  into one another
• - particles can sometimes behave like waves

• Quantum mechanical state can be
• the sum of several states
• - let is suppose nm is sum of two different
• mass states (or matter waves)
• - might seem odd, but is perfectly allowable
• - can generate the interference
  pattern
• we call neutrino oscillations ?

34
?µ
?µ
sometimes the waves are in-phase
wave 1
wave 2
wave 1 wave 2
sometimes they are out of phase
35
Neutrino Oscillations

• neutrinos waves can oscillate between types
• but only if they have different masses
• this interference causes first the disappearance
• then reappearance of the original n type
• ? a neutrino can change its identity!

36
How Do You Weigh a Neutrino?

• so if we move the detector some distance away, a
  fraction
• of the muon neutrinos will become electron or
  tau neutrinos

MiniBooNE is looking for nm ? ne at Los Alamos
frequency MINOS is looking for nm ? nt at
Atmospheric frequency
37
Whats Next?

• Just Around the Corner two experiments to look
  at neutrino interactions with detectors that are
  closer to microscopes
• SciBooNE take detector from Japan, beamline
  from Fermilab Booster
• MINERvA bring brand new detector in, as well as
  nuclear physicists who want to see if neutrinos
  can tell what nucleus they are interacting in
• Both will help still the next generation of
  oscillation experiments

38
Whats next for Oscillations?

• Just around two corners NOvA
• Best chance for seeing neutrino anti-neutrino
  differences!
• Will use the same neutrino beamline as MINOS
• Brand new detector in northern Minnesota better
  able to distinguish electrons (squirrels) from
  anything else

39
Why Neutrinos and Anti-Neutrinos?

• Every fundamental particle has an anti-matter
  partner
• When they meet, they annihilate into pure energy.
  Alternatively, energy can become matter plus
  anti-matter

40
So you might ask

• The early Universe had a lot of energy. Where is
  the anti-matter in the Universe?
• Good question how do we know it isnt around
  today?
• look for annihilations.
• As far away as we can tell, today there arent
  big matter and anti-matter collisions
• Maybe its the neutrinos which are different from
  anti-neutrinos!

41
Conclusions

• Neutrinos are everywhere all the time
• We wouldnt be here without them
• We are just beginning to understand what they are
  
• We have built the most powerful neutrino beams
  and are getting to the best measurements of
  neutrinos changing flavors
• Weve only just begun

42
In Gratitude

• Thank you for funding our research.  I find that
  when I talk to people about the science that we
  do there is interest and pride that we, as a
  nation, are able and willing to pursue new and
  fundamental scientific knowledge.  Although many
  do not understand the details, the American
  people seem to understand that fundamental
  science is worth pursuing and is important to the
  future of our country.  We need to push back
  frontiers of our knowledge.  More practically,
  basic scientific research proves to be a wise
  investment for the future through creation and
  development of new technologies to which it
  invariably leads.  Thank you for the opportunity
  you have given us to pursue this remarkable
  science.
• Next, I would like to express deep respect and
  personal thanks to my colleagues both within and
  outside MINOS for your support, not only over the
  last couple of months but over the last decade of
  building this facility and experiment together. 
  Scientific results are of course the goal, but
  they come only at the end of a long and arduous
  process.  It is only possible to get there by
  working together with people of great skill and
  diligence.  The end result may be just a hard
  number, but the process is intrinsically human. 
  It is a pleasure to have so many fine colleagues
  with whom to share this work. 
• Finally, in my recent diagnosis and treatment I
  have frequently found myself marveling at the
  technology that is available for 21st century
  medical care.  It is very gratifying to me to
  know that many of the basic ideas and techniques
  for modern imaging equipment were either first
  developed IN our own field of high-energy physics
  or BY people TRAINED in our field.  I have gotten
  a first-hand view of the remarkable achievements
  in the engineering, technology, chemistry, and
  medicine which enable us to effectively treat
  diseases like the one that I have.  And just as
  in physics, the glue that brings it all together
  and makes it work are dedicated and skilled
  professionals.  Just as in our own field, the
  combination of technology and people can produce
  fantastic results.   

Doug Michael, March 30 2005