LISA bar attenuation measurement - Westmont College

Using a 60Co source we measured the spectral location of the 60Co Compton edge as a function of source position along the LISA bar in order to measure the light attenuation. Below are the results for each PMT. Since the total attenuation is dependent on both bulk properties of the material and on the internal reflection profile, the first two points in each plot (i.e those closest to the PMT's) were eliminated from the exponential fits in order to obtain better agreement. The resulting attenuation length for the LISA bar is approximately 5.8 m, in very good agreement with that of the MoNA bars.