Selection criteria for P- and N-channel JFETs as input elements in low-noise radiation-hard charge preamplifiers

This paper describes a quantitative method for the selection of P- and N-ch annel junction field-effect transistors as input elements in low-noise char ge-sensitive preamplifiers for applications requiring high radiation tolera nce. The method is based upon a thorough analysis of ionizing radiation eff ects on the noise spectral density of such devices. It can be used to predi ct whether a P- or an N-type transistor is preferable as the front-end elem ent of a preamplifier once the radiation doses and the electronic system re adout times are known. Such criteria can be useful in the design of low-noi se radiation-resistant electronics suitable for applications where high lev els of total radiation dose are expected during the circuit lifetime.