Congratulations are in order for Dr John Cesar, who defended his PhD dissertation today. John was supervised by Professor Karol Lang of the University of Texas at Austin.

Dr John Cesar and a happy dog For his thesis project, John looked for periodic variations in the double beta decay of $^{100}$Mo in the NEMO-3 dataset. This was the first ever search for periodic variations in a second-order weak nuclear process. No periodicity was found, and he was able to set a limit of a maximum 2.2% for yearly modulations, at the 90% confidence level.

To enable similar studies to be carried out with even higher precision on SuperNEMO, John worked on a calibration and monitoring system for the calorimeters. This light-injection system will inject, via optical fiber, UV light from light emitting diodes into each module to track its behavior between absolute calibration runs to a precision of 1%.

John is now with University College London, working on the CHIPS neutrino detector (CHerenkov detector In mine Pits). CHIPS, located in Minnesota, USA, aims to demonstrate a new concept for more cost-effective mega-ton scale neutrino detectors using the water in flooded mine pits. The CHIPS detector is situated in Fermilab’s NuMI neutrino beam, and will be used to study long-baseline neutrino oscillations. John is involved in detector R&D, including development and construction of the optical modules that will be employed in the detector to help image the Cherenkov light for event reconstruction. He also works on the electronics and data acquisition and the water filtration system.

Well done, John! We wish you all the best for the future.