SNO+ supernova sensitivity during pure scintillator phase

(Full abstract, which includes a graph, cannot be displayed here. For full abstract see thesis pdf.) SNO+ is a liquid scintillator experiment looking for a neutrinoless double beta decay in 130Te. Observing this decay would mean that neutrinos are Majorana particles, one of the possible extensions to the Standard Model. Additionally, this decay allows one to measure the effective mass of the neutrino, something that is still unknown. To observe this very rare decay mode new stringent cleanliness requirements are necessary. Because of this, a new calibration system (TELLIE) was commissioned for SNO+ that does not require a deployment inside the detector. TELLIE is based on an array of LEDs delivering light via optical fibres. The calibration procedure using this system, its performance, and a comparison to a deployed calibration source is presented. TELLIE was found capable of providing calibration to the required precision. SNO+ also has unique sensitivity to core-collapse supernova neutrinos from our galaxy. A burst trigger with the aim to detect and alert on a supernova burst was developed, built, and commissioned for SNO+. The detection mechanism is outlined. A complementary monitoring platform was produced to provide an initial analysis of the detected bursts. The trigger was tested on a supernova Monte Carlo. Additionally, it was proven to be sensitive to the sudden changes in the activity of the detector, detecting an earthquake and issues with the electronics. A procedure to analyse a neutrino burst once detected is also suggested. It consists of a tagging method to distinguish the inverse beta decay events, an energy correction for energetic positrons, and an analysis of cuts to clean the burst from the backgrounds. This method is used to extract basic observables from a supernova explosion and evaluate the sensitivity of SNO+ during the scintillator phase.