Neutrino observatory

Neutrino observatories (also known as neutrino telescopes , neutrino detectors or - somewhat too general - neutrino experiments ) are particle detectors specially designed for the detection and measurement of neutrinos from distant sources. 100 meters or more are considered to be far away.

Because neutrino reactions have very small cross sections, neutrinos only rarely react with normal matter . Neutrino detectors must therefore be very large and usually collect data for years in order to achieve statistically significant measurement results.

On the earth's surface, the rare neutrino events are obscured by the much more frequent signals from muons of secondary cosmic rays . That is why the neutrino detectors are installed at great depths of the sea, under mountains or in mines that are no longer in use.

According to the place of origin of the observed neutrinos a distinction can be made between

• cosmic neutrinos (space)
• solar neutrinos (sun)
• atmospheric neutrinos (earth's atmosphere)
• Geoneutrinos (Earth's interior)
• Reactor neutrinos (nuclear reactors)
• Neutrinos from accelerator experiments

Important neutrino observatories

Some important neutrino observatories are listed in the table below.

Neutrino experiments
observatory	sensitivity	Detector type	Detector material	Reaction type	reaction	Threshold energy
ANTARES , Mediterranean, France	cosmic ${\displaystyle \nu _{\mu }}$	Cherenkov	H 2 O	charged electricity	${\displaystyle \nu _{\mu }}$+ N → - + X + N → + + X muons ${\displaystyle \mu }$ ${\displaystyle {\overline {\nu }}_{\mu }}$ ${\displaystyle \mu }$	> 10 GeV	[1]
Borexino , Gran Sasso, Italy	low energy solar ${\displaystyle \nu _{e}}$	Scintillator	H 2 O C 6 H 3 (CH 3 ) 3 C 15 H 11 NO	elastic scattering	${\displaystyle \nu _{x}}$+ e - → + e - ${\displaystyle \nu _{x}}$	250-665 keV	[2]
CLEAN	low-energy solar , as well as from supernovae and pulsars ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{e}}$	Scintillator	liquid neon	elastic scattering	${\displaystyle \nu _{x}}$+ e - → + e - + 20 Ne → + 20 Ne ${\displaystyle \nu _{x}}$ ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{e}}$	?	[3]
Daya Bay , Daya Bay , China	Reactor neutrinos	Scintillator	organic Gd complex	charged current (inverse beta decay)	${\displaystyle {\overline {\nu }}_{e}}$+ p + → n + e +	1.8 MeV	[4]
Double Chooz , Chooz	Reactor neutrinos	Scintillator	organic Gd complex	charged current (inverse beta decay)	${\displaystyle {\overline {\nu }}_{e}}$+ p + → n + e +	1.8 MeV	[5]
GALLEX , Gran Sasso, Italy	solar ${\displaystyle \nu _{e}}$	radiochemical	GaCl 3 (30 t Ga )	charged electricity	${\displaystyle \nu _{e}}$+ 71 Ga → 71 Ge + e -	233.2 keV	[6]
GNO , Gran Sasso, Italy	low energy solar ${\displaystyle \nu _{e}}$	radiochemical	GaCl 3 (30 t Ga )	charged electricity	${\displaystyle \nu _{e}}$+ 71 Ga → 71 Ge + e -	233.2 keV	[7]
HERON	mainly low energy solar ${\displaystyle \nu _{e}}$	Scintillator	superfluid helium	neutral electricity	${\displaystyle \nu _{e}}$+ e - → + e - ${\displaystyle \nu _{e}}$	1 MeV	[8th]
Homestake – Chlorine , Homestake Mine, USA	solar ${\displaystyle \nu _{e}}$	radiochemical	C 2 Cl 4 (615 t)	charged electricity	37 Cl + → 37 Ar * + e - 37 Ar * → 37 Cl + e + + ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{e}}$	814 keV	[9]
Homestake – Iodine , Homestake Mine, USA	solar ${\displaystyle \nu _{e}}$	radiochemical	NaI	elastic scattering, charged current	${\displaystyle \nu _{e}}$+ e - → + e - + 127 I → 127 Xe + e - ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{e}}$	789 keV	[10]
ICARUS , Gran Sasso, Italy	solar and atmospheric neutrinos, and , , of CERN ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{\mu }}$ ${\displaystyle \nu _{\tau }}$	Cherenkov	liquid argon	elastic scattering	${\displaystyle \nu _{e}}$+ e - → + e - ${\displaystyle \nu _{e}}$	5.9 MeV	[11]
IceCube , South Pole	atmospheric and cosmic , , , possibly more ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{\mu }}$ ${\displaystyle \nu _{\tau }}$	Cherenkov	1 km³ H 2 O (ice)	charged electricity	${\displaystyle \nu _{x}}$+ N → x + X mainly muons	> 200 GeV; ≈ 10 GeV with DeepCore extension	[12]
INO , Ino Peak, India	atmospheric neutrinos	Resistance plate chamber	Glass	elastic scattering, charged current	${\displaystyle \nu _{e}}$+ e - → + e - + no → e - + p + + p + → e + + no ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{e}}$	?	[13]
Kamiokande , Kamioka, Japan	solar and atmospheric ${\displaystyle \nu _{e}}$	Cherenkov	3,000 t H 2 O	elastic scattering	${\displaystyle \nu _{e}}$+ e - → + e - ${\displaystyle \nu _{e}}$	7.5 MeV	[14]
KamLAND , Kamioka, Japan	Reactor neutrinos, geoneutrinos ${\displaystyle {\bar {\nu }}_{e}}$	Scintillator			${\displaystyle {\bar {\nu }}_{e}+p\to e^{+}+n}$	1.8 MeV	[15]
LENS , Gran Sasso, Italy	low energy solar ${\displaystyle \nu _{e}}$	Scintillator	In (MVA) x	charged electricity	${\displaystyle \nu _{e}}$+ 115 In → 115 Sn + e - + 2γ	120 keV	[16]
MOON , Washington, USA	low-energy solar and low-energy supernova- ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{e}}$	Scintillator	100 Mo (1 t) + MoF 6 (gaseous)	charged electricity	${\displaystyle \nu _{e}}$+ 100 Mo → 100 Tc + e -	168 keV	[17]
OPERA , Gran Sasso, Italy	${\displaystyle \nu _{e}}$, , From CERN ${\displaystyle \nu _{\mu }}$ ${\displaystyle \nu _{\tau }}$	Hybrid	2000 t Pb / emulsion + muon spectrometer	charged electricity	${\displaystyle \nu _{\tau }}$+ N → + X ${\displaystyle \tau }$	4.5 GeV	[18]
RENO , Yeonggwang , South Korea	Reactor neutrinos	Scintillator	organic Gd complex	charged current (inverse beta decay)	${\displaystyle {\overline {\nu }}_{e}}$+ p + → n + e +	1.8 MeV
SAGE , Baksan, Russia	low energy solar ${\displaystyle \nu _{e}}$	radiochemical	GaCl 3	charged electricity	${\displaystyle \nu _{e}}$+ 71 Ga → 71 Ge + e -	233.2 keV	[19]
SNO , Sudbury Mine, Canada	solar and atmospheric , , ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{\mu }}$ ${\displaystyle \nu _{\tau }}$	Cherenkov	1000 t D 2 O	charged current, neutral current, elastic scattering	${\displaystyle \nu _{e}}$+ 2 1 D → p + + p + + e - + 2 1 D → + n o + p + + e - → + e - ${\displaystyle \nu _{x}}$ ${\displaystyle \nu _{x}}$ ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{e}}$	6.75 MeV	[20]
Super Kamiokande , Kamioka, Japan	solar and atmospheric , , and , , of KEK ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{\mu }}$ ${\displaystyle \nu _{\tau }}$ ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{\mu }}$ ${\displaystyle \nu _{\tau }}$	Cherenkov	32,000 t H 2 O	elastic scattering, charged current	${\displaystyle \nu _{e}}$+ e - → + e - + no → e - + p + + p + → e + + no ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{e}}$ ${\displaystyle \nu _{e}}$	?	[21]
UN , Henderson Mine, USA	solar, atmospheric and reactor neutrinos	Cherenkov	440,000 t H 2 O	elastic scattering	${\displaystyle \nu _{e}}$+ e - → + e - ${\displaystyle \nu _{e}}$	?	[22]