Download - NEUTRINOS AT HOMESTAKE PAST & FUTURE
Kenneth Lande - Pierre, S.D.
NEUTRINOS AT HOMESTAKE
PAST & FUTURE
KENNETH LANDE
UNIVERSITY OF PENNSYLVANIA
PIERRE, S.D. JANUARY 20, 2004
Kenneth Lande - Pierre, S.D.
N e u tr in o B e a m f ro m B ro o k h a v e n N a tio n a l L a b o ra to ry to th e N a tio n a l U n d e rg ro u n d S c ie n c e L a b o ra to ry
Enhanced AGS
MillionWatt
Proton Beam
DetectorAt Homestake
One milliontons ofwater
Neutrino flight path – 2540 km
Kenneth Lande - Pierre, S.D.
History of the Problem
1859- Charles Darwin-published “Origin of Species”
1862- Kelvin challenged Darwin since the time required for biological evolution exceeded the gravitational
lifetime of the Sun
P.E.(Sun) = GM2 /R and
2
History of the Problem
1859- Charles Darwin-published “Origin of Species”
1862- Kelvin challenged Darwin since the time required for biological evolution exceeded the
gravitational lifetime of the Sun
P.E.(Sun) = GM2 /R and
t = P.E./solar power = 3x107 yrs
Kelvin won the debate – but was
WRONG!
The Sun is a nuclear fusion reactor
Kenneth Lande - Pierre, S.D.
History of the Neutrino Program at the Homestake Mine
• In 1962, Raymond Davis first looked for neutrinos from the Sun with a small detector, about 1000 gallons, in the 2300 ft deep Barberton Mine in Ohio. The background was enormous.
• Brookhaven and the Bureau of Mines looked for a much deeper location – Homestake was the best choice in 1964,
• IT STILL IS•
Kenneth Lande - Pierre, S.D.
Kenneth Lande - Pierre, S.D.
Kenneth Lande - Pierre, S.D.
Results of the Homestake Solar Neutrino Experiment
• Observed neutrinos from the center of the Sun – proved Sun is a fusion reactor
• The observed neutrino intensity was 1/3 of that expected – implied that 2/3 of the neutrinos produced in the Sun changed into other types of neutrinos during their flight from the Sun to the Earth
• Started the field of Neutrino Astrophysics
Kenneth Lande - Pierre, S.D.
The Next Detector – Kamioka, Japan
• A 50,000 ton water detector at a depth of about 2500 ft. [Koshiba from Kamiokande & Davis from Homestake shared the 2002 Nobel Prize in Physics]-
• Each of the ten 100,000 ton Homestake modules will be similar
Kenneth Lande - Pierre, S.D.
The Next Step
• Use an accelerator to produce a neutrino beam of known intensity, known composition and known energy
• Establish a long range (2500 km) neutrino beam through the Earth
• Requires a very intense beam (a million watts of protons) and a very large detector (a million tons)
Kenneth Lande - Pierre, S.D.
At Brookhaven the beam aims 11.4o into the Earth – goes under the northern U.S. and surfaces at Homestake
Each of the 10 Homestake modules is the height of a 20 story building and the ½ the length of a football field
Kenneth Lande - Pierre, S.D.
MEGATON MODULAR MULTI-PURPOSE DETECTOR
March 2002Mark A. Laurenti
Modular Configuration
Kenneth Lande - Pierre, S.D.
MEGATON MODULAR MULTI-PURPOSE DETECTOR
Modular Configuration
Mark A. Laurenti March 2002
6950 Level
Kenneth Lande - Pierre, S.D.
Expected Observations:
Directly observe the transformation of neutrinos from one species to another
Look for bursts of neutrinos from supernova in our Galaxy & in adjacent galaxies
Search for proton decay to 1035 years lifetime
Kenneth Lande - Pierre, S.D.
Scientific Goals
Detection of proton decay will tell us about the ultimate fate of matter
Pierre Jan. 20, 2004
Differences in the rate of species transformation of neutrinos and anti-neutrinos may explain how an equal mixture of matter and anti-matter in
the early Universe became the all matter world in which we live
Kenneth Lande - Pierre, S.D.
Kenneth Lande - Pierre, S.D.
Other Possible Results
• There is also the possibility of a “matter effect” which produces a change of neutrino
type proportional to the amount of matter passed through. This effect, if observed,
could lead to a new tool for the investigation of the interior of the Earth,
• Neutrino Tomography
Kenneth Lande - Pierre, S.D.
Kenneth Lande - Pierre, S.D.
MEGATON MODULAR MULTI-PURPOSE DETECTOR
Estimated Timeline
Year Four
Mark A. Laurenti
6950
7100
March 2002
60 ft Cable Bolts
4 Bottom Cuts
Precast Liners
Shotcrete 1ft
Waterproof Liner
Kenneth Lande - Pierre, S.D.
Cosmic ray flux at depth of 3MDetector = 0.2 muons/m2, day
Each 100 kT module has an areaof 2000 m2 and thus 800 muons/day
Assuming a neutrino pulse width ofone microsecond/sec gives 1 cosmic ray events per year in the 10 module Megaton detector during the AGS neutrino pulses