Extraction of noise spectral densities(intrinsic and irradiation contributions) of a charge preamplifier based on JFET

Experimental RMS voltage noise of a charge preamplifier based on JFET (Junction Field Effect Transistor) are carried out. These data are fitted with some models of the JFET noise sources. The spectral densities of current and voltage noise are extracted according to the model giving the best agreement between experimental and simulated curves. Intrinsic noise sources and those induced after irradiation by Gamma ray and neutrons are analyzed. The total spectral density and the contribution of each source are also reported.