20 January 2005 Steve Dye, HPU 1
Neutrino Geophysics in Hawaii
Presentation by Steve DyeAssociate Professor of Physics
Hawaii Pacific University
January 20, 2005
20 January 2005 Steve Dye, HPU 2
Outline of Presentation
Neutrinos Geophysics Neutrino Geophysics HANOHANO
20 January 2005 Steve Dye, HPU 3
Neutrinos
Discovery Place in nature Properties Detection
– Astrophysics– Nuclear reactors
http://www.flyingneutrinos.com
20 January 2005 Steve Dye, HPU 4
Discovery of Neutrino W. Pauli proposes
undetected particle in β-decay (1931)
E. Fermi develops theory of β-decay with “little neutral one” (1934)
C. Cowan and F. Reines detect neutrinos at nuclear reactors (1950's) http://www.ps.uci.edu/physics/reinesphotos.html
20 January 2005 Steve Dye, HPU 5
Neutrino’s Place in Nature
http://www.particleadventure.org/particleadventure/frameless/chart.html
20 January 2005 Steve Dye, HPU 6
Neutrino Properties
Come in three flavours– e, μ, τ
No electric charge Stable Weak interactions Massive (slightly) Flavour oscillations
20 January 2005 Steve Dye, HPU 7
Neutrino Detection
http://www.ps.uci.edu/physics/reinesphotos.html
http://www-sk.icrr.u-tokyo.ac.jp/doc/sk/photo/normal.html
http://www-personal.umich.edu/~jcv/IMBdiverbig.jpg
20 January 2005 Steve Dye, HPU 8
Neutrino Astrophysics
Neutrinos are excellent astrophysical probes– Stable, uncharged, weakly-interacting
Low energy (eV scale)– Detection of “Big Bang” neutrinos difficult
Medium energy (MeV scale)– Detection of stellar neutrinos established
High energy (TeV to EeV scale)– Detection of extragalactic neutrinos
progressing
20 January 2005 Steve Dye, HPU 9
Neutrino Astrophysics- SN1987a
http://www-personal.umich.edu/~jcv/imb/imbp5.html
20 January 2005 Steve Dye, HPU 10
http://elvis.phys.lsu.edu/svoboda/superk/cossun.pdf http://elvis.phys.lsu.edu/svoboda/superk/sun.gif
20 January 2005 Steve Dye, HPU 11
Neutrinos from Nuclear Reactors
http://www.insc.anl.gov/pwrmaps/map/world_map.php
20 January 2005 Steve Dye, HPU 12
Underground Neutrino Detector
KamLAND in Japan– 1000 tonnes of
liquid scintillator– ~2000 PMTs– Rate in 400 tonnes
~1/(2 days) from reactors at 180 km
20 January 2005 Steve Dye, HPU 13
Anti-Neutrino Detection
from John G. Learned “Monitoring All Earth Reactors”
20 January 2005 Steve Dye, HPU 14
Neutrinos in Japan KamLand signal
primarily neutrinos from nuclear reactors
Neutrinos from Earth detected!
Raghavan hep-ex/0208038
20 January 2005 Steve Dye, HPU 15
Summary Point #1
Neutrinos exist with measured properties
Neutrinos carry information from deep inside stars, galaxies, and Earth
Neutrinos of energy ~1 MeV can be detected using proven techniques
20 January 2005 Steve Dye, HPU 17
Seismology Earthquake waves
– Pressure waves• P (primary) waves
– Shear waves• S (secondary) waves
Solids– Transmit P and S
waves Fluids
– Transmit only P waves
http://www.mantleplumes.org/Energetics.html
20 January 2005 Steve Dye, HPU 19
Geodynamo
Magnetic field– Dipole– Convection in outer
core– Rotation of Earth
Magnetic field required for life to exist– Deflects radiation– Helps retain
atmospherehttp://www.es.ucsc.edu/~glatz/geodynamo/html
20 January 2005 Steve Dye, HPU 20
Global Heat Flow
http://www.geo.lsa.umich.edu/IHFC/heatflow.html
http://www.geo.lsa.umich.edu/IHFC/heatflow.html
>24,000 field measurements
20 January 2005 Steve Dye, HPU 21
Earth Radioactivity Long-lived radioactive isotopes Decay of heavy elements heats the Earth How much heat and from where are the main
questions U/Th/K distribution in the core, mantle, crust
http://neutrino2004.in2p3.fr/slides/monday/fiorentini.pdf
20 January 2005 Steve Dye, HPU 22
Summary Point #2
Much to be learned in geophysics– Composition of mantle and core– Origin of Earth– Source of heat flow– Mechanism of geodynamo
20 January 2005 Steve Dye, HPU 23
Geo-neutrinos
Anti-neutrinos from the Earth
Arise from decay of radioactive elements (U+Th+K) in crust, mantle, and maybe core
Detection above 1.8 MeV proven (U+Th)
Domogatsky et al., hep-ph/0409069
Rothschild, Chen and Calaprice: nucl-ex/9710001
20 January 2005 Steve Dye, HPU 24
Geo-neutrinos
Contributions from continental crust, oceanic crust, and mantle
Possible observational sites– Japan– Italy– Canada– Russia– Curacao– Hawaii
20 January 2005 Steve Dye, HPU 25
Geo-neutrinos at Curacao
Dutch project– Long, narrow
underground shafts– Instrumented with
nuclear detectors– Strives to measure
neutrino direction Goal: Neutrino
tomography of Earth
R.J. de Meijer EARTH Info-001
20 January 2005 Steve Dye, HPU 26
Anti-Neutrinos from the Core
J. Marvin Herndon Breeder (fission)
reactor deep within inner core
Explains heat flow, geomagnetic field variability, He3/He4
Power output 3-10 TW Observable through
neutrino emission
20 January 2005 Steve Dye, HPU 27
Geo-reactor neutrinos
Test of geo-reactor hypothesis requires special location for clear signal– Far from man-made
reactors– Far from continental
crust Hawaii is excellent
siteRaghavan hep-ex/0208038
20 January 2005 Steve Dye, HPU 28
HANOHANO(Hawaiian for magnificent)
Hawaii Anti-Neutrino Observatory New initiative in Hawaii for neutrino geophysics
project Objectives are:
– Measure geo-neutrinos from mantle and U/Th– Test geo-reactor hypothesis
Method:– Deploy KamLAND-like detector in the deep (4-5 km) ocean
near Hawaii and operate for about 1 year Funding:
– Submitting proposal to CEROS next week for design study– If successful, propose CEROS follow-on for prototype testing– Next go for order of $100M from NSF for full detector
20 January 2005 Steve Dye, HPU 29
Deep Ocean Technology
Hawaii-2 Observatory– Deployed in 1998– Another off Japan ’93
Neutrino detector possible in 3-5 years
http://oceanusmag.whoi.edu/images/v42n2-chave1en.jpg
20 January 2005 Steve Dye, HPU 30
Summary and Conclusion
Neutrino detection is a viable (only?) method for learning what is inside Earth
Various neutrino geophysics projects being considered around the globe
Hawaii is an excellent site for a project Deep ocean technology sufficiently
advanced HANOHANO
Top Related