Speaker
Dr
Helen O'Keeffe
(Queen's University, Kingston)
Description
The SNO+ liquid scintillator neutrino experiment is under construction
in the SNOLAB facility, located approximately 2 km underground in
Sudbury, Ontario, Canada. The goals of this multi-purpose experiment
include precision measurements of low energy components of the solar
neutrino flux and a search for the elusive neutrinoless double beta
decay process through addition of neodymium in a separate phase of the
experiment. A detailed understanding of the linear alkyl benzene
(LAB) scintillator and its optical properties is crucial to the
success of this experiment.
To this end, an acrylic cylinder capable of holding approximately 1
litre of scintillator was deployed in a water filled SNO+ detector in
autumn 2008. By deploying the cylinder with an Americium Beryllium
(AmBe) source (external to the cylinder), the scintillator light yield
was determined in the actual detector, helping to tune the detector
Monte Carlo.
The cylinder was deployed without the AmBe source to search for
background contamination using a beta-alpha coincidence method. Alpha
peaks from radon were used to derive Birks' constant and alpha
quenching factors. The beta-alpha coincidence events were used to
provide a sample of betas and alphas which were used in timing and
pulse-shape discrimination studies. Three different types of LAB
scintillator were studied during the test deployment, including LAB
loaded with 0.1% natural neodymium. This poster will present the
design of the apparatus, preparation of the scintillator samples,
results from this small scale test and their implications for the SNO+
experiment.
This work is presented on behalf of the SNO+ collaboration.
Primary author
Dr
Helen O'Keeffe
(Queen's University, Kingston)
Co-authors
Dr
Christine Kraus
(Laurentian University, Sudbury)
Dr
H.S. Wan Chan Tseung
(University of Washington)
Dr
Jeanne Wilson Hawke
(Queen Mary, University of London)