Development of Digital Signal Processing (DSP) based systems for nuclear pulse processing

摘要

Nuclear pulse processing plays central role in any nuclear spectroscopy system. Here, nuclear pulses from scintillation/solid state detectors are analyzed as per the amplitude and the spectrum is generated which helps in identifying and measuring radioactive isotopes. In a traditional or analog signal processing system, spectroscopy amplifier is employed for the functions gain, shaping, pole zero cancellation, base line restoration, pulse pile up rejection. In this paper, general Digital Signal Processing (DSP) based system is introduced. Major advantages with reference to nuclear pulse processing are discussed. Properties of nuclear pulse and output pulse (trapezoidal shaped pulse) are discussed. Digital filter which converts typical nuclear pulse to the desired output pulse using convolution techniques is derived. Algorithm to process nuclear pulses is presented for the spectroscopic functions. Based on the above algorithm, computer code in 'C language was developed and tested using DSP board, SBC6711. Three portable gamma ray spectrometers were fabricated and field-testing is under progress.