Lambert Function in the Determining of the Noise Equilibrium Frequency for Radiation Detectors

We analyze several cases of combined noise in sensors for radiation and in sensor-amplifier circuits. Solutions are shown to involve the Lambert function of various variables when the unknown is a frequency limit of the bandwidth. The coverage of the paper is essentially theoretical and its two aims are to exemplify the use of Lambert function in noise analysis and to help improving the design of pre-amplifiers, especially for radiation detectors.