Abstract: The ultra-low background flow gas proportional counter is the ideal detector for total α/β sample measurement, but itself has strong crosstalk phenomenon, which affects the accuracy of sample measurement. This paper systematically studies the flow type proportional counter under the same mass thickness, different ²⁴¹Am and ⁴⁰K mass fractions α→β, β→α Cross channel influence. This paper established a binary equation for total α/β channel correction and compared it with the cover correction method and with the self-made 25 groups α/β simulate powder samples for measurement and channel correction. The results show that: The impact of α→β crosstalk is significant; The change with α counting rate is not constant; The influence of the β→α channel correction factor is relatively small, with an average value of 0.001. The accuracy of the measurement results is poor by using the cover correction method to correct the simulated powder β sample, with absolute relative deviation ranging from 1.4% to 45.0%. The binary equation correction method is used to correct the simulated powder β sample. The accuracy of the measurement results is relatively high, with an absolute value of relative deviation ranging from 0 to 5.5%.

Key words: ultra low background flow proportional counter, cross-talk, binary equation correction method