A novel acquisition method of nuclear spectrum based on pulse area   analysis
  A novel method based on pulse area analysis(PAA) was presented for acquisition nuclear spectrum by the digitizer. PAA method can be used as a substitute for the traditional method of pulse height analysis (PHA). In the PAA method a commercial digitizer was employed to sample and sum in the pulse, and the area of pulse is proportional to the energy of the detected radiation. The results of simulation and experiment indicate the great advantages of PAA method, especially when the count rate is high and shaping time constant is small. When shaping time constant is 0.5us, the energy resolution of PAA is about 66% better than that of PHA. 
Li Dongcang, Ren Zhongguo, Yang Lei, Qi Zhong, Meng Xiangting, Hu   Bitao
physics.ins-det nucl-ex