表面粗糙度对正比计数器性能的影响研究OA

Proportional counters are a key technology for monitoring gaseous tritium due to their high sensitivity and direct measurement capabilities.However,the effect of cathode wall surface roughness on their performance remains underexplored.This paper systematically controls the surface roughness(Ra)of stainless steel(SS304)cathodes in the range of 0.01-0.32 μm to investigate the correlation between surface morphology and detector performance.Experimental results demonstrate that reduced roughness increased the water contact angle from 80.0° to 88.4° and reduce surface energy from 35.488 mN·m-1 to 34.143 mN·m-1,thereby weakening physical adsorption of gases(e.g.,CH4,O2).A positive correlation is observed between surface roughness and plateau slope:at Ra=0.32 μm,the slope is 2.7％/100 V.It decreases to 0.7％/100 V at Ra=0.01 μm,with sensitivity stability improving nearly 3-fold.The background count rate decreases significantly from 17 s-1 to 3.3 s-1,a reduction of 80.6％.This performance enhancement stems from a synergistic mechanism involving reduced adsorption sites,suppressed secondary electron emission,and optimized electric field uniformity.Continuous monitoring for 140 h in low-concentration tritium environments(～102 Bq·L-1)shows no significant memory effect.This paper confirms cathode surface roughness as a critical factor in proportional counter performance,providing theoretical foundations for high-performance detector design.