1. Student Lecture on Neutrino Detectors
Basics : Neutrino Source & Interactions
Survey of Detection Techniques
Projects
Experimentalists
Theorist
Henry T. Wong / 王子敬
Academia Sinica / 中央研究院
@ THU / 清華大學
November 2002

2. Nobel Prize in Physics (2002) 50% for n astrophys. :
Ray. Davis Jr. (U. Penn) :
“Classic” Chlorine Expt.
Masatoshi Koshiba 小柴昌俊 (U. Tokyo) :
Kamiokande & SuperK
Citations leave room for future prizes on n physics !!!
50% to Riccardo Giacconi, in X-Ray Astronomy

3. Neutrino History 1914: continuous b-spectra (Chadwick)
1930: postulation of neutrinos (Pauli)
1934: theory of b-decay (Fermi)
calculation of s(np) (Bethe,Peierls)
1956: observartion reactor ne (Reines,Cowan)
1957: measurement of n helicity (Goldhaber)
1962: discovery of accelerator nm (BNL)
1968: observation of solar neutrinos (Davis)
1974: discovery of weak neutral currents (CERN)
1987: observation of supernova SN1987a n’s (IMB,Kamiokande)
1989: three families of light neutrinos (CERN)
1998: evidence of atmospheric neutrino oscillation (Super-Kam., …)
2000: observation of nt (Fermilab)
2001: evidence solar neutrino oscillation (SNO+SK+GALLEX ……)

4. Neutrino Sources n‘s everywhere: 300 per c.c.
Observed window
n‘s everywhere:
300 per c.c.
from sun, supernovae, cosmic rays, reactors, accelerators, astrophysical sources, & relic Big Bang …

5. Neutrino Physicist :

6. Cross Sections Challenges of Neutrino Experiments :
Strong
Electro-magnetic
Weak
 l(H2O)  250 light years !
BUT ….. En~ 1015 eV, L~Earth’s diameter
Challenges of Neutrino Experiments :
“How to Beat the Small Cross-Section?”
i.e. By building Massive Detectors
 while keeping cost/background Low !

7. Neutrino Detection : Summary
※ keV Neutrinos:
R&D: Cryogenic techniques
※ keV-MeV Neutrinos:
Proven: Radiochemical Techniques (solar neutrinos with Cl, Ga)
R&D : World efforts to develop counter/real time+energy methods
TEXONO on Reactor Neutrinos: Crystal Scintillator, Solid-State Device
※ MeV-GeV Neutrinos:
R&D: Water Cherenkov Detector, Liquid Scintillator
※ GeV-TeV Neutrinos:
Proven: multi “high energy physics” detector systems
※ Astrophysical UHE Neutrinos:
Projects: Water/Ice Cherenov, Radio/Sound Waves, Cosmic-Ray Showers ..

8. Radio-chemical Experiments –
extracting 30 atoms from 30 tons (1029 atoms) of target materials.
e.g. GALLEX: ne+71Ga71Ge, detected by EC X-rays

9. Favorite Technique for Massive Detector: Cherenkov Radiation
Permits one
Sensor to see
Area of Λ2atten
E. Kearns, BU

10. Super-Kamionkande
※ Water Cerenkov detector: 5k tons, viewed by 11,000+ =50 cm PMTs
in 1000 m underground site in central Japan
※ Physics: solar n, atmospheric n , long baseline accelerator n, proton decays ..
※ Accidents (PMTs imploded) Nov 01, 50% PMT data again end of 02 !!!

12. SK >5 MeV e-ring from ne+e scattering
The Sun IS Burning !!

13. SK sub-GeV events from atmospheric n interactions
m-ring from nmN
e-ring from neN
NC events with p0  2g

14. Sudbury Neutrino Observatory (SNO)
※ Heavy Water Cerenkov detector: 1k ton, shielded
by 7k ton of water viewed by 9456 PMTs located
2000 m underground in Canada.
※ Physics: Solar n …

15. Actual measurements : only detect e- (a burst of light) : deconvolute the channels

16. (also Cl, Ga, diff. E)
(also SK)
( 5s effect )

17. “Reines’ Reaction” for ne Detection : ne+pe++n
detect e+ then delayed n-capture
modern version : liquid scintillator (proton target)
Discovery of Neutrinos , Reines 1956

18. KamLAND
Long Baseline Reactor n (sensitive to 20% of world’s reactors !)
ave. flight path of 160 km
1 kton liquid scintillator in old Kamiokande site
probe “LMA” for solar n
first results “any time” (only 5 years from approved !!!!)

19. Accelerator n (1-10 GeV) Experiments :
typical high energy physics techniques -
 tracking m for Q/p,
 calorimetry for em/had. Showers
CC: nm+Nm-+X(shower)
NC: nm+N nm +X(shower)

20. CHORUS
NOMAD

21. Historic Bubble Chamber Neutrino Interaction Events
nm+Nm-+X(shower)
nm+e-nm+e- nm e- nm m-

22. Modern “Bubble Chamber” : Liquid Argon Time Project Chamber

23. Direct Observation of nt with Nuclear Emulsion
nN Emulsion
Events from nt
Field of View : 100 mmX120 mm

24. Optical Cherenkov Neutrino Telescope Projects
Gaols: detect astrophys. n at eV
ANTARES
La-Seyne-sur-Mer, France
BAIKAL
Russia
NEMO
Catania, Italy
DUMAND
Hawaii
(cancelled 1995)
NESTOR
Pylos, Greece
AMANDA, South Pole, Antarctica

25. IceCube – km3 n Telescope
※ To detect high
energy ( eV) n’s
South Pole
AMANDA
IceCube

26. IceCube 1015 eV ntN event (sim.) “Double Bang Event”
AMANDA “upward-going” m event τ
Decay length
O(100 m) at 1015 eV ντ

27. Radio Chenrenkov Detectors :
for > 1015 eV neutrinos; target- Moon, Antartic Ice, Salt mine ……

28. En > 1015 eV : using surface of Earth as target

29. En > 1019 eV: Detection of Cherenkov/florescence light from space

30. Summary & Outlook Neutrinos are important but strange objects
history of n physics full of surprises !
Strong evidenceS of massive n’s & finite mixings
Physics Beyond the Standard Model !
More experiments & projects coming up
EVEN MORE EXCITEMENT !
TEXONO is also a (modest) part of it

31. How Science Makes Progresses ……….