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


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


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


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•




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


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


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)


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


MEGATON MODULAR MULTI-PURPOSE DETECTOR

March 2002Mark A. Laurenti

Modular Configuration



Modular Configuration

Mark A. Laurenti March 2002

6950 Level


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


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



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




Estimated Timeline

Year Four

Mark A. Laurenti

6950

7100

March 2002

60 ft Cable Bolts

4 Bottom Cuts

Precast Liners

Shotcrete 1ft

Waterproof Liner


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

NEUTRINOS AT HOMESTAKE PAST & FUTURE

Documents

kmkenneth lande pierre

levelkenneth lande pierre

similarkenneth lande

tonskenneth lande pierre

neutrino intensity

neutrino program

bursts of neutrinos

transformation of neutrinos