Signal Processing for Radiation Detectors

2Signals, Systems, Noise, and Interferences

This chapter begins with a brief description of the different types of pulses commonly used in detector pulse processing, followed by a review of the basic concepts in the analysis of the response of a pulse processing circuit to input signals. The concepts introduced in this chapter have similar representations and relationships for discrete‐time and digital signals, which will be discussed later in Chapter 9. We also review the different sources of noise and interferences in pulse processing systems together with the common techniques of minimizing the effects of interferences on detector signals. The noise filtration process will be discussed in Chapter 4. A reader interested in a more detailed treatment of signals and systems and also electronic noise may refer to the textbooks and references cited in the text.

2.1 Pulse Signals: Definitions

An electronic pulse is defined as a brief surge of current or voltage. A pulse may carry information in one or more of its characteristics such as amplitude and shape or simply its presence. In radiation detectors, a pulse generally starts out with a surge of current that is converted to a voltage pulse at the output of the detector readout circuit. The characteristics of the voltage pulse can carry various information such as energy, timing, position, or type of the particle. The basic characteristics of a pulse signal are shown in Figure 2.1. A pulse, in general, consists of two parts. The ...