A fast multichannel analyzer for radiation detection applications

This work reports on the development of a multichannel analyzer (MCA) circuit for use in radiation detection. The MCA is based on a fast analog-to-digital converter (ADC) plus a digital circuitry programmed on a complex programmable logic device (CPLD). The ADC digitizes the input signals with high accuracy and low nonlinearity while the CPLD performs the histogramming process of the acquired voltage amplitudes. The MCA basic operations are carried on by a logic state machine implemented in the CPLD, triggered by a 20-MHz clock. This approach has allowed us to reduce the circuit dead time to 200 ns. Other performance parameters are related to the used ADC chips. Results are shown that illustrate competitive results as compared to commercially available MCAs.