Developments in interpolative pad read out of liquid argon sampling calorimeters

The authors report here recent developments on interpolative pad read out, dubbed BRITE Pads, of liquid argon sampling calorimeters. They have constructed model devices and made bench tests of their performance under various conditions. They report on the performance of a two element linear BRITE PAD system and a four element four moment BRITE PAD system. The results from the linear system are from a model electromagnetic calorimeter tower. To duplicate the fast pulse of an electromagnetic shower, they developed a fast laser, optical fiber and photodiode system; the photodiode fits within the 2 mm gap. The fast signals, about 10 pC discharged in 10 ns, were read out with BNL designed amplifiers followed by 50 ns RCCR shaping