the borexino experiment - istituto nazionale di fisica...
TRANSCRIPT
Borexino is similar to a "matrioska", dipped in 2.400 tons of highly purified water.
Inside it, a steel sphere contains 1000 tons of a hydrocarbon (pseudocumene) and within a smaller nylon sphere are 300 tons of scintillating liquid
In the innermost sphere neutrinos interact with the scintillator liquid and produce small flashes of light. Borexino observes dozens of these signals every day
The photomultipliers, which are ultra-sensitive technological eyes, see and record the light flashes produced by the neutrinos
Thermonuclear fusion in the Sun produces continually enormous quantities of neutrinos reaching the Earth: each second, 60 billions of them pass through a finger's tip
Borexino observes low energy neutrinos (less then 1 Mev) that are produced on the solar core's surface
Nylon sphere,diameter 8,5 m
Stainless steel sphere,diameter13,7 m
2.200photomultipliers
(inwards)
Muons apparatus:200 photomultipliers
(outwards)
300 tonsscintillator
liquid
Thin nylon layer(radon gas barrier)
Shieldingsteel dishes
Stainless steelbox of water,
diameter 18 m
water
ScintillatorScintillator
Hydrocarbon layerHydrocarbon layer(pseudocumene)(pseudocumene)
Scintillator
Hydrocarbon layer(pseudocumene)
Carrier chordsThe Borexino experiment
NEUTRINOS
SUN
1,5 kmof rocks
Borexino
Gran SassoMount
Neutrinos, which are neutral particles with a very small mass, interact very rarely with the other constituents of matter and can pass unhindered through enormous thicknesses of every kind of material
Borexino is an international project with Italian leadership, involving research centres of six different countriesand about 100 experts, between physicists, engineers and technicians.
To detect them, big apparatuses are needed. They are placed underground to shield the signals produced by other particles coming from the Cosmos and the natural radioactivity of the environment
Gran Sasso