The Sudbury Neutrino Observatory (SNO) is a real time solar neutrino experiment. The detector utilizes 1,000 metric tons of heavy water to study the fundamental properties of neutrinos. The SNO detector has been designed to measure the flux and energy spectrum of electron-type solar neutrinos in addition to measuring the total flux of all active flavors of solar neutrinos. The primary objective of SNO is to resolve the Solar Neutrino Problem. The measurement of the neutron signal is critical to the success of SNO. Therefore, it is imperative that one thoroughly understands the various backgrounds to the neutron signal. Even though the rock overburden of 6,150 meter water equivalent provides a very good shield to cosmic muons, enough of them penetrate the detector to produce secondary particles, in particular neutrons. In this dissertation results from the study of through-going muons and neutron production due to muon spallation in the SNO detector has been presented. The following daily muon rate was found: <display-math> <fd> <fl>RSNOm=68.9± 1.8(stat) day-1</fl> </fd> </display- math>The following muon-induced neutron rate was obtained, where Nmult is the neutron mutliplicity: <display-math> <fd> <fl>Rmspn [1≤Nmult≤14] [SNO,AV] measured=(11.49±0.74) day-1kt-1</fl> </fd> </display-math> A primary component of the SNO detector is the data acquisition (DAQ) system. The author has been intricately involved in the design and implementation of the DAQ system and a detailed discussion of this system has been presented in this dissertation. The system was successfully deployed in late 1997 and acquisition of production data commenced in November of 1999. Although there have been minor changes to the DAQ system over the course of time, the system has been operating successfully since production data taking began in 1999.
- Pub Date:
- October 2002
- Physics: Astronomy and Astrophysics