Speaker
Description
The SNO+ experiment is a kilotonne-scale neutrino detector located 2km underground at SNOLAB in Sudbury, Ontario. A primary goal of SNO+ is to further our understanding of the Standard Model (SM) and the nature of neutrinos through a search for neutrinoless double beta decay (0$\nu$$\beta$$\beta$) in $^{130}$Te. A 0$\nu$$\beta$$\beta$ detection would measure the absolute neutrino mass, extend physics beyond the SM, and offer insights into the unexplained neutrino mass mechanism. The long decay half-life ($>10^{25}$yrs) and backgrounds near the decay Q-value ($\sim2.5$MeV) pose great challenges in detecting 0$\nu$$\beta$$\beta$. A key component of effective background modeling is the reconstruction of the energy and position of physics events within the detector. To accomplish this, a calibration campaign was designed to measure the detector optical response. \
The detector consists of a 12m diameter acrylic vessel currently filled with 780 tonnes of liquid scintillator, linear alkylbenzene, doped with the fluor 2,5-diphenyloxazole, viewed by approximately 9400 photomultiplier tubes (PMTs) and surrounded by a shielding volume of ultra-pure water. In SNO+, a photon from a physics event is subjected to optical processes on its trajectory from the interaction vertex to the PMTs. These optical processes include scattering, absorption, and re-emission from the scintillator, acrylic, and external water; and reflection and refraction at media boundaries. Both the optical processes and PMT response are position, energy and wavelength dependent. An ideal optical calibration source, the Laserball, was developed, which produces quasi-isotropic light at well-defined wavelengths, and can be deployed throughout the detector. This talk presents the optical calibration from the first deployment of the SNO+ Laserball in the scintillator phase.
| Keyword-1 | Neutrino Physics |
|---|---|
| Keyword-2 | Astroparticle Physics |
| Keyword-3 | Calibration |