The unfolding-synthesis technique is commonly used in digital pulse processing systems for nuclear radiation measurements.

This study aims to propose a novel flat-topped widened peak-shaping algorithm based on the pulse unfolding-synthesis technique is proposed.

Firstly, the repetition and polynomials were utilizes to shape the digital pulses, and the nuclear pulse signal was unfolded into unit pulses series. Then, an impulse response system was employed to synthesize these unit pulses series to achieve the desired peak shape. Finally, the improved flat-topped peak-shaping algorithm was compared and analyzed against traditional filter shaping algorithms in terms of accuracy in amplitude extraction, interference resistance, and pile-up recognition.

Experimental results demonstrate that, under the same shaping time, the energy resolution of the flat-topped peak-shaping algorithm for the γ characteristic peak of ¹³⁷Cs is 7.2%, outperforming the trapezoidal, triangular, and Gaussian shaping algorithms. Additionally, it exhibits high counting rate performance.

The flat-topped peak-shaping algorithm of this study can effectively replace traditional pulse-shaping methods and be utilized for high-precision, high-count-rate γ spectroscopy measurements.