SUBJECT: Ph.D. Dissertation Defense
BY: Eric Burgett
TIME: Friday, April 2, 2010, 9:00 a.m.
PLACE: Boggs, 3-47
TITLE: Novel Neutron Detectors
COMMITTEE: Dr. Nolan E. Hertel, Chair (NRE)
Dr. Chris Wang (NRE)
Dr. Chaitanya Deo (NRE)
Dr. Christopher Summers (MSE)
Dr. Ben Klein (ECE)
Dr. Ian Ferguson (ECE)
Dr. Tony Hill (NE)


A new thermal neutron detector solution has been developed as a near term 3He tube replacement. The Zinc Oxide scintillator is an ultrafast scintillator which can be doped to have performance equal to or superior to 3He tubes. Originally investigated in the early 1950s, this room temperature semiconductor has been evaluated as a thermal neutron scintillator. Zinc oxide can be doped with different nuclei to tune the band gap, improve optical clarity, and improve the thermal neutron detection efficiency. A study into various dopant effects on the scintillation properties, materials properties, and crystal growth parameters has been accomplished. Two different growth modalities were investigated; bulk melt grown materials as well as thin film scintillators grown by way of the metalorganic chemical vapor deposition (MOCVD) method. This method has shown significant advantages including precise thickness control, high dopant incorporation, and epitaxial coatings of neutron target nuclei. Detector designs were modeled and simulated to design an improved thermal neutron detector including doped ZnO layers, conformal coatings and light collection improvements including Bragg reflectors. The detectors have been tested in for crystalline quality by XRD and FTIR spectroscopy, for scintillation efficiency by photo-luminescence spectroscopy, and for neutron detection efficiency by alpha and neutron radiation tests. Lastly, a novel method for improving light collection efficiency has been investigated, the creation of a photonic crystal scintillator. Here, the flow of optical light photons is controlled through an engineered structure created with the scintillator materials. This work has resulted in a novel radiation detection material for the near term replacement of 3He tubes with performance characteristics equal to or superior to that of 3He.