A.W.P. Poon^{§ &}, M.C. Browne^§, N.P. Kherani^¶, R.J. Komar^&, H.-B. Mak^#, R.G.H. Robertson^§ and C.E. Waltham^&

^§Nuclear Physics Laboratory, University of Washington, Seattle, WA 98195, USA
^& Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada V6T 1Z1
^¶Ontario Hydro Technologies, 800 Kipling Avenue, Toronto, ON, Canada M8Z 5S4
^#Department of Physics, Queen's University, Kingston, ON, Canada K7L 3N6

The Sudbury Neutrino Observatory (SNO) is a 1000-tonne heavy water Cerenkov detector being constructed near Sudbury, Ontario, Canada. The SNO detector is located two kilometres underground in the Creighton Mine owned by INCO Limited.

Details of the technical specifications of the SNO detector can be found here.

Our group works on the construction of a high energy calibration gamma-ray source for energy calibration of the SNO detector. The gamma-rays are generated through proton capture on tritium, which has a Q-value of 19.8 MeV. This high energy gamma-ray source is shown in the picture below.

Features of this source:

• Compact and Portable
  It is compact enough to go down the calibration port connected to the acrylic vessel of the SNO detector. In fact, it fits inside a 10 inch diameter by 24 inch stainless steel capsule for lowering into the heavy water volume during calibration. Power to the source is delivered by cable from external power supplies.
• "No" Maintenance
  To ensure that the radioactive contamination from tritium be minimal, no maintenance is required to the tritiated parts of the source. There is no external vacuum pump or gas bottle attached to the source.
• Low Operating Voltage
  The source has an adequate gamma-ray production rate for energy calibration at SNO at a beam energy of as low as 20 keV.

Related Links

• Department of Physics, Queen's University, SNO Home Page
• Department of Physics and Astronomy, University of British Columbia, SNO Home Page
• Nuclear Physics Laboratory, University of Washington, Electroweak Interaction Group Page
• Ontario Hydro Corporate Home Page and Ontario Hydro Technologies Home Page

Last Updated: April 1, 1997