Studies of silicon photodetectors for scintillator-based Hadron Calorimetry at the International Linear Collider

We present results on the operation and performance characteristics of the Metal/Resistor/Semiconductor (MRS) photodiode. These include measurements of threshold characteristics, noise frequency, dependence of signal amplitude on the applied voltage and temperature, and stability as a function of time and radiation dose. The single photoelectron separation for this photosensor is demonstrated with a light-emitting diode. The response of the photodetector to light produced in scintillator is studied with cosmic ray muons and a 106Ru source. In addition, fiber-sensor alignment issues were evaluated. The results are promising and illustrate the potential use of MRS as photosensors in high energy physics detectors.