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-channel junction field-effect transistors as input elements in low-noise charge-sensitive preamplifiers for applications requiring high radiation tolerance. The method is based upon a thorough analysis of ionizing radiation effects on the noise spectral density of such devices. It can be used to predict whether a P- or an N-type transistor is preferable as the front-end element of a preamplifier once the radiation doses and the electronic system readout times are known. Such criteria can he useful in the design of low-noise radiation-resistant electronics suitable for applications where high levels of total radiation dose are expected during the circuit lifetime.