We show data from a new type of detector that can be used to determineneutron flux, energy distribution, and direction of neutron motion for bothfast and thermal neutrons. Many neutron detectors are plagued by largebackgrounds from x-rays and gamma rays, and most current neutron detectors lacksingle-event energy sensitivity or any information on neutron directionality.Even the best detectors are limited by cosmic ray neutron backgrounds. Allapplications (neutron scattering and radiography, measurements of solar andcosmic ray neutron flux, measurements of neutron interaction cross sections,monitoring of neutrons at nuclear facilities, oil exploration, and searches forfissile weapons of mass destruction) will benefit from the improved neutrondetection sensitivity and improved measurements of neutron properties madepossible by this detector. The detector is free of backgrounds from x-rays,gamma rays, beta particles, relativistic singely charged particles and cosmicray neutrons. It is sensitive to thermal neutrons, fission neutrons, and highenergy neutrons, with detection features distinctive for each energy range. Itis capable of determining the location of a source of fission neutrons based oncharacteristics of elastic scattering of neutrons by helium nuclei. Thedetector we have constructed could identify one gram of reactor gradeplutonium, one meter away, with less than one minute of observation time.
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