SPACE AND COSMIC RAY PHYSICS SEMINAR

University of Maryland
Atlantic Building, Room 2400 4:30 PM Monday, February 4, 2008
Coffee, Tea & Snacks 4:15-4:30 PM

Michael A. Coplan
University of Maryland

A New Way of Detecting Neutrons, Atomic and Nuclear Physics Meet

Neutrons were discovered 75 years ago, but the detection of these fundamental constituents of matter remains difficult and inefficient. Reliable, efficient, and robust neutron detectors are a high priority for the the detection of illicit nuclear materials as well as for the new applied and fundamental neutron science facilities that are being commissioned. A new kind of neutron detector that overcomes the limitations of current detectors will be discussed. The detector uses the reaction of thermal neutrons with 3He to produce several tens of Lyman alpha vacuum ultraviolet (120 nm) photons for every neutron reacted. A complete understanding of the photon production requires detailed consideration of the initial nuclear reaction as well as the subsequent charge exchange and electronic excitation collision processes.