Papers Published

1. Schaffer, J.P. and Shaughnessy, E.J. and Jones, P.L., The deconvolution of Doppler-broadened positron annihilation measurements using fast Fourier transforms and power spectral analysis, Nucl. Instrum. Methods Phys. Res. B, Beam Interact. Mater. At. (Netherlands), vol. 233 no. 1 , pp. 75 - 9 .
   (last updated on 2007/04/06)

   Abstract:
   A deconvolution procedure which corrects Doppler-broadened positron annihilation spectra for instrument resolution is described. The method employs fast Fourier transforms, is model independent, and does not require iteration. The mathematical difficulties associated with the incorrectly posed first order Fredholm integral equation are overcome by using power spectral analysis to select a limited number of low frequency Fourier coefficients. The FFT/power spectrum method is then demonstrated for an irradiated high purity single crystal sapphire sample

   Keywords:
   Doppler effect;Fourier transforms;positron annihilation in liquids and solids;