Oxygen Monitoring in Xylene NTOF Detectors

Xylene scintillators are used to perform neutron time of flight measurements at LLE. Oxygen is dissolved in the xylene to reduce the scintillation decay time and improve timing response. Currently, there is no way to monitor the oxygen level in the detector. Using cosmic ray muons as a free and safe surrogate for neutron radiation, variations in muon scintillation waveforms are hoped to predict the oxygen level and xylene quality in situ without breaking the hermetic seal of the detector. Nuclear Magnetic Resonance (NMR) spectroscopy is being used to identify oxidation reactions degrading the scintillator. This data gives an indication for when the scintillator fluid should be changed. These studies are hoped to lead to an understanding of the oxidation chemistry of the scintillator.