the SUDBURY neutrino detector

(1 kiloliter of D2O surrounded by 9500 photomultiplier tubes)



inverse beta decay
(CC = charged current)
fission 
(NC =  neutral current)
elastic scattering 
(ES = electron scattering)
(identical to the SK experiment)


neutrino
reactions

n
e  +   d  --> 
p  +  p  +  e-

[nmt  +   d  -->  p  +  p  +  m-/t-
cant happen]



 
ni + d  --> 
n
i  + p + n

[i stands for any flavor of
n:
e or
m  or  t ]

comes in 2 varieties:
ni   +    e   -->    ni   +  e

ne   +   e-     -->    e-    ne
(but with a 6x greater probability than above)

threshold
energy

1.4 Mev
2.2 Mev =
binding energy
of  deuterium
5 Mev
or else insignificant
Cerenkov radiation
over the background

detection
method

e- Cerenkov radiation
(isotropic)
n capture by
deuterium produces
an excited tritium
that decays via a
6.25-Mev 
g ray

e-   Cerenkov radiation
(directed)
what's being measured
only the ne flux
the total n flux
mostly ne flux with some ni flux
experimental detections
(relative to theoretical neutrino flux)

0.33 +  0.03

0.97 + 0.05

0.46  +  0.03  (SNO)
0.43  +  0.01  (SK data)  

capture rate
fne = 1.76 + 0.11 
(x 106 
ne/cm2/s)
fni = 5.09 + 0.11  fni = 2.39  + 0.23
=
fne + (fnm + fnt)/7

[ fni = 2.30  + 0.03  (SK data) ]