Experimental verification of a method to create a variable energy neutron beam from a monoenergetic, isotropic source using neutron elastic scatter and time of flight

Zachary D. Whetstone, Marek Flaska, Kimberlee J. Kearfott

Research output: Contribution to journalArticle

1 Scopus citations


An experiment was performed to determine the neutron energy of near-monoergetic deuterium-deuterium (D-D) neutrons that elastically scatter in a hydrogenous target. The experiment used two liquid scintillators to perform time of flight (TOF) measurements to determine neutron energy, with the start detector also serving as the scatter target. The stop detector was placed 1.0 m away and at scatter angles of π/6, π/4, and π/3 rad, and 1.5 m at a scatter angle of π/4 rad. When discrete 1 ns increments were implemented, the TOF peaks had estimated errors between -21.2 and 3.6% relative to their expected locations. Full widths at half-maximum (FWHM) ranged between 9.6 and 20.9 ns, or approximately 0.56-0.66 MeV. Monte Carlo simulations were also conducted that approximated the experimental setup and had both D-D and deuterium-tritium (DT) neutrons. The simulated results had errors between -17.2 and 0.0% relative to their expected TOF peaks when 1 ns increments were applied. The largest D-D and D-T FWHMs were 26.7 and 13.7 ns, or approximately 0.85 and 4.98 MeV, respectively. These values, however, can be reduced through manipulation of the dimensions of the system components. The results encourage further study of the neutron elastic scatter TOF system with particular interest in application to active neutron interrogation to search for conventional explosives.

Original languageEnglish (US)
Pages (from-to)95-101
Number of pages7
JournalNuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
StatePublished - Aug 11 2016


All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Instrumentation

Cite this