高功率脉冲微波照射时大鼠体内SAR值计算

Calculation of SAR in rats exposed to pulsed high power microwave irradiation

目的 计算高功率脉冲微波照射条件下大鼠体内的比吸收率 (SpecificAbsorptionRate ,SAR)分布。方法 在建立的脉冲辐射场及大鼠电磁模型的基础上 ,采用时域有限差分法计算大鼠体内的感生电场分布 ,进而得到比吸收率。结果 计算了不同脉宽和重复频率条件下的峰值比吸收率和平均比吸收率 ,并按防护标准的要求分别计算了SAR1、SAR10和WBA SAR。结论 照射条件相同 ,仅改变微波脉冲宽度 ,峰值比吸收率变化很小 ;在同一次照射中 ,比吸收率按SAR1Max、SAR10Max和全身平均SAR值依次下降 ,存在局部“热点” ;在相同的远场照射条件下 ,实验动物越小 ,全身平均SAR值越大。

Objective To investigate the SAR distribution in rats exposed to pulsed high power microwave irradiation. Methods Based on established pulsed EM fields and a numerical rat model, the distribution of the induced electric field in rats was calculated using FDTD method to get SAR distribution. Results The peak SAR and averaged SAR were calculated in different irradiation conditions,and SAR1,SAR10 and WBA-SAR were also calculated. Conclusion Peak SARs change little for different pulse width under same irradiation conditions.In one irradiation,the SAR descreases in turn for SAR1 peak,SAR10 peak and WBA-SAR.For pulsed high power microwave irradiation,there is a local “hotspot”.Under the same farfield irradiation,the smaller the rat is, the larger the WBASAR would be.;