TAU NEUTRINO DOUBLE BANG MIMICS WITH ICECUBE
Open Access
- Author:
- Boyer, Lance L
- Area of Honors:
- Physics
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Douglas Cowen, Thesis Supervisor
Douglas Cowen, Thesis Supervisor
Dr. Richard Wallace Robinett, Thesis Honors Advisor - Keywords:
- Neutrino
Astrophysics
Physics
IceCube - Abstract:
- Astronomy and particle astrophysics with the IceCube Neutrino Observatory benefit from tau neutrino detection. Tau neutrinos produce distinct, nearly background free electromagnetic showers within the volume of IceCube which may be reconstructed to find extragalactic point sources. Some of the properties of neutrinos useful to astrophysics are reviewed before discussing the importance of the tau neutrino in particular. The tau neutrino events occurring within the IceCube detector may be distinguished from other neutrino events by a characteristic electromagnetic cascade known as a ``double bang'. The reconstruction of these tau neutrino `double bang' events may benefit greatly from calibration provided by flashing LEDs within IceCube to simulate the effect of the electromagnetic cascade generated by creation and annihilation of a tau lepton. Flasher LEDs were deployed in situ in Digital Optical Modules and are utilized to recreate the ``double bang' conditions. Although the search for the double bang tau neutrino event geometry with existing flasher data provided a few useful events for configuration, the possibility of creating a larger calibration data set was explored. A Monte Carlo simulation shows a quadratically increasing relationship between the number of actively flashing IceCube modules and the number of expected calibration events. Further analysis of previous flasher data showed a linear dependence on the number of launch channels triggered by an LED flash and both the brightness and module depth. Using the prior flasher data a novel data run utilizing 120 modules was run on January 14, 2011. The large scale flasher run produced 21 tau neutrino mimic events. Further investigation revealed that the online trigger used to filter the events was suboptimal due to a strong dependence on the number of launch channels and radial distance from the center of IceCube DeepCore. The linear relationship between flasher radial distance and the number of launch channels provides a clear parameter for configuring a larger and more efficient flasher run in the future.