Chapter 8
Neutrino Detectors
Leslie Camilleri
After a brief introduction describing the many sources of neutrinos, this article will
describe the various detector techniques that are being used to observe neutrinos of
energies ranging from a few MeV to hundred’s of GeV.
8.1 Historical Introduction
In 1930 in order to explain the continuous energy spectrum of electrons emitted
in beta decay, Pauli postulated [1] that these electrons were emitted together with
a light neutral particle. This particle was subsequently named the neutrino. Their
actual observation had to wait until 1953 when Reines and Cowan recorded [2]
interactions of anti(electron)neutrinos emitted by a reactor in a cadmium doped
liquid scintillator detector. Since then, in addition to the ν e , two other flavours of
neutrinos were observed, the ν μ and ν τ . The ν μ , which is produced in π → μ
decay, was proved to be different [3] from the ν e in an experiment at Brookhaven
using thick-plate optical spark chambers. The ν τ , companion of the τ lepton, was
observed [4] at Fermilab in an emulsion cloud chamber detector consisting of iron
plates interleaved with sheets of photographic emulsions. Although until recently
neutrinos were thought to be massless and were described as such in the Standard
Model, in the past decade they have been found to be massive [5, 6]. Furthermore
each of the three flavour states mentioned above consists of a superposition of three
mass states of unequal masses leading to oscillations of one flavour into another
under the appropriate conditions. The characteristics of these oscillations depend on
three mixing angles θ 13 , θ 12 and θ 23 as well as on the difference of the square of the 3
L. Camilleri ()
Nevis Labs, Columbia University, Irvington-on-Hudson, NY, USA
e-mail: camil@nevis.columbia.edu
© The Author(s) 2020
C. W. Fabjan, H. Schopper (eds.), Particle Physics Reference Library,
https://doi.org/10.1007/978-3-030-35318-6_8
337
Neutrino Detectors
Leslie Camilleri
After a brief introduction describing the many sources of neutrinos, this article will
describe the various detector techniques that are being used to observe neutrinos of
energies ranging from a few MeV to hundred’s of GeV.
8.1 Historical Introduction
In 1930 in order to explain the continuous energy spectrum of electrons emitted
in beta decay, Pauli postulated [1] that these electrons were emitted together with
a light neutral particle. This particle was subsequently named the neutrino. Their
actual observation had to wait until 1953 when Reines and Cowan recorded [2]
interactions of anti(electron)neutrinos emitted by a reactor in a cadmium doped
liquid scintillator detector. Since then, in addition to the ν e , two other flavours of
neutrinos were observed, the ν μ and ν τ . The ν μ , which is produced in π → μ
decay, was proved to be different [3] from the ν e in an experiment at Brookhaven
using thick-plate optical spark chambers. The ν τ , companion of the τ lepton, was
observed [4] at Fermilab in an emulsion cloud chamber detector consisting of iron
plates interleaved with sheets of photographic emulsions. Although until recently
neutrinos were thought to be massless and were described as such in the Standard
Model, in the past decade they have been found to be massive [5, 6]. Furthermore
each of the three flavour states mentioned above consists of a superposition of three
mass states of unequal masses leading to oscillations of one flavour into another
under the appropriate conditions. The characteristics of these oscillations depend on
three mixing angles θ 13 , θ 12 and θ 23 as well as on the difference of the square of the 3
L. Camilleri ()
Nevis Labs, Columbia University, Irvington-on-Hudson, NY, USA
e-mail: camil@nevis.columbia.edu
© The Author(s) 2020
C. W. Fabjan, H. Schopper (eds.), Particle Physics Reference Library,
https://doi.org/10.1007/978-3-030-35318-6_8
337