dSpectral-directional relative intensity of the light scattered by a Tyvek
sample, immersed in water, has been measured for visible and UV wavelengths
. The obtained information is useful to simulate the behavior of light in w
ater Cherenkov detectors, such as those proposed for the observation of hig
h energy cosmic ray air showers. In this work a simple empirical dependence
of the scattering pattern on the angle was found, convenient to be used in
Monte Carlo simulation programs. (C) 1999 Elsevier Science B.V. All rights
reserved.