Chapter No. 10 General description of electronic units used in radiation measurements. viewpoint of ‘ input-output'-i.e., the input and output signals of component unit or instrument minimum of discussion on circuitry. Awareness of the capabilities and limitations of the different types of units Develop the capacity to choose the right component for a specific counting system. Details about construction and operation of electronic components and systems given in specialized books and products manual.

Pulse Processing Chapter No. 16 Radiation Detection and Measurements, Glenn T. Knoll, Third edition (2000), John Willey .

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10.6 PULSE SHAPING The pulse produced at the output of a radiation detector has to be modified or shaped for better performance of the counting system. There are three reasons that necessitate pulse shaping: 1. To prevent overlap. Each pulse should last for as short a period of time as possible, and then its effect should be abolished so that the system may be ready for the next pulse. Without pulse shaping, the detector signal lasts so long that pulses overlap. If only the number of particles is counted, pulse overlap leads to loss of counts (dead time loss). In spectroscopy measurements, pulse overlap worsens the resolution. 2. To improve the signal-to-noise ratio. Noise created in the detector and the early amplification stages accompanies the detector signal. Appropriate pulse shaping can enhance the signal while at the same time reduce the noise. Thus, the signal-to-noise ratio will improve, which in turn, leads to better energy resolution. 3. For special pulse manipulation. The detector pulse may, in certain applications, need special pulse shaping to satisfy the needs of certain units of the counting system. As an example, the signal at the output of the amplifier needs to be stretched before it is recorded in the memory of a multichannel analyzer (see Sec. 10.12). The pulse-shaping methods used today are based on combinations of RC circuits and delay lines. For example, the use of a CR-RC circuit combination produces the pulse shown in Fig. 10.15.

10.4 AN INTEGRATING CIRCUIT An integrating circuit also consists of a resistor and a capacitor, but now the output signal is taken across the capacitor (Fig. 10.9). Equation 10.20 applies in such a case too, and the output signal as a result of a step input is given by: