NSERC grants at Laurentian University Subventions du CRSNG `a l ...

140Arthur McDonald with/avec A. Bellerive, M. Chen, H. Evans,G. Ewan, Jacques Farine, A. L. Hallin, Doug Hallman, C. Hargrove,R. Helmer, R. Hemingway, J. Law, J. Leslie, H. Mak,A. Noble, R. Ollerhead, S. Oser, B. Robertson, D. Sinclair,Clarence Virtue, C. Waltham 3Sudbury Neutrino Observatory project grant B. On-siteoperatingA grant of $7,100,000 for two years.Une subvention de 7.100.000 $ pour deux ans.Subatomic Physics Project – Projet en physique subatomiqueThe Sudbury Neutrino Observatory is a large international project tostudy fundamental constituents of the Universe called neutrinos. Observationof neutrinos gives information on the thermonuclear processes in the Sunand tests theoretical calculations. For over thirty years there was a discrepancybetween these calculations and the initial measurements of neutrinosfrom the Sun that had come to be known as the “Solar Neutrino Problem”.Neutrinos are extremely hard to detect. The detector must be placed deepunderground to protect it from natural cosmic rays and all materials usedmust be extremely free from radioactivity. SNO uses 1000 tonnes of heavywater from Canada’s reserves and is located 2 km underground at Inco’sCreighton mine near Sudbury, Ontario. The international collaboration iscomprised of Canadian institutions (Carleton, Guelph, Laurentian, Queen’s,UBC, TRIUMF), six from the US and two from the UK.In 2001 and 2002, the SNO collaboration published papers that provideda clear solution to the “Solar Neutrino Problem”. These results showed definitivelythat about 2/3 of the neutrinos produced in the Sun have changedto other types before reaching the Earth, thereby escaping detection in previousexperiments. This process can occur if neutrinos have a finite massbut was not previously included in the most fundamental theories of elementaryparticle physics. The SNO results show that calculations of the Sunare very accurate. In 2003, the SNO collaboration presented further, moreaccurate, results from the second phase of the experiment with salt in the3 The names of the researchers from Laurentian University are shown in italics./Les noms des chercheurs de l’UniversitéLaurentienne sont en italiques.