Performance of a radiation hard 128 channel analogue front-end chip for the readout of a silicon-based hybrid photon detector

The performance is described of a front-end chip, the SCT128A-LC chip, originally developed for the readout of a silicon based Hybrid Photon Detector (HPD), which is part of an RICH detector to be run in an LHC experimental environment. The relatively low signal charge from single photoelectrons, impinging on the silicon pad sensor, put very stringent requirements on the noise performance of the front-end chip. An absolute noise calibration using X-ray sources and a **2**4**1Am gamma source was performed. It is demonstrated that sufficiently good signal over noise ratio can be obtained to use this chip for the read-out of an HPD in LHC experiments.