Wavelength Shifter in the heavy water of the Sudbury Neutrino Observatory
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 Etienne Rollin, Carleton University  

In order to have access to the lower energy part of the Boron-8 solar
neutrino energy spectrum, a proposal has been made to add wavelength
shifter molecules (WLS) to the heavy water of the Sudbury Neutrino
Observatory (SNO).  WLS should increase the number of photons detected
per event while keeping the external backgrounds at a low level. This
has the potential to lower the energy threshold cut currently used by
the SNO collaboration.  Montecarlo studies show that using a
Carbostyril-124 solution at a concentration of 1 ppm, one can lower
the energy threshold from 5.5 to 3.5 MeV.  The physics implications of
such a reduction will be discussed.