title: Time-of-flight calibration of a 6Li glass epithermal neutron detector
abstract: The curing of Portland cement concrete involves the conversion of water from a free to a bound state. The process can be monitored nondestructively by measuring the shift in the neutron energy spectrum in the epithermal range (0.025-1 eV). A tuned array of 6Li glass detectors has been constructed with varying efficiencies over the epithermal energy range. To determine the efficiency of each detector as a function of neutron energy, it is necessary to calibrate it against a reference neutron spectrum. This was accomplished using a time-of-flight approach with a pulsed neutron beam produced at the Gaerttner LINAC Laboratory at Rensselaer Polytechnic Institute. With a neutron flight path of 25 m it was possible to determine the neutron detector efficiencies to an energy resolution of 11 microeV. The data showed good agreement with the detector design calculations.
authors.affiliation: Office of Infrastructure R&D, Federal Highway Administration, McLean, VA 22101, USA. dick.livingston@fhwa.dot.gov
authors.initials: RA
authors.lastname: Livingston
authors.initials: HH
authors.lastname: Saleh
authors.initials: RC
authors.lastname: Block
authors.initials: PJ
authors.lastname: Brand