Publications [#245033] of Mohammad W. Ahmed

Papers Published
  1. Ahmed, MW; Feldman, G; Litvinenko, VN; Nelson, SO; Norum, BE; Perdue, B; Pinayev, IV; Sawatzky, B; Tonchev, AP; Wu, Y; Weller, HR, Background reduction in FEL-generated γ-ray beam experiments using giant high-peak power pulses, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 516 no. 2-3 (January, 2004), pp. 440-444 [doi] .

    A new method to eliminate beam-uncorrelated background in photonuclear experiments has been developed at the High Intensity Gamma-Ray Source (HIγS). Background suppression of over 3 orders-of-magnitude has been achieved by using a gain modulation technique to generate giant high-peak power (GHPP) pulses in the OK-4/ Duke storage ring FEL. The time structure of these laser pulses was tuned so that their duration was ∼100 μs, repeated every 50 ms. The associated FEL photons were backscattered from 780 MeV electrons to produce linearly polarized 40 MeV γ-rays having the same time structure as the FEL pulses. As an initial test of the technique, a nearly background-free measurement of the analyzing power in the Compton scattering reaction 16O(γ→,γ)16O was performed. © 2003 Elsevier B.V. All rights reserved.