A fast data acquisition method based on pulse-width analysis was developed for measuring neutron capture cross-sections using an NaI(Tl) detector. The new method was tested by detecting gamma-rays from standard gamma-ray sources and neutron-induced reactions. Non-linear relation between the gamma-ray energy and the pulse width of the detector output signal was studied. The neutron beam experiments were performed using a pulsed neutron beam from a spallation neutron source at the Japan Proton Accelerator Research Complex. Detector-deposited energy spectra were reconstructed from the pulse-width spectra using the parameterized relation between the pulse width and the gamma-ray energy. Time response properties of the pulse-width analysis method were compared with the traditional pulse-height analysis method. Detailed analysis of the experimental results demonstrated that the present method was more resistive to intense gamma-ray bursts from the spallation neutron source. (C) 2014 Elsevier B.V. All rights reserved.