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根据微扰理论,本文导出了适用于螺旋波导谐振腔(也适用于圆柱谐振腔)腔场测量的介质球微扰公式。该公式已考虑了微扰球的有限大小及谐振腔径向场的影响,故用作圆柱谐振腔轴向场分布测量时,比斯莱特(Slater)公式有更高的精度。我们在螺旋波导谐振腔上进行了实验验证。利用本文的数学处理方法还能导出其它形状微扰体及其它场型的微扰公式。由于推导中把测量球的微扰作用仅考虑至电四极子,而忽略了更高次电极子的作用,故还是有局限性的,但已能初步满足腔场测量的要求。 相似文献
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周志孝 《核技术(英文版)》1991,(4)
A formula describing the percentage depth dose curve for ~(60)Co γ beams is theoretically developed. The formula only needs a few data determined by measuring directly in water phantom and can be used to calculate the whole set of percentage depth dose (PDD) and tissuse air ratios (TAR) for the wide range of SSD (from 20cm to 100cm), field size (from 4cm×4cm to 20cm×20cm) and depth (from d_m to 30cm). The data calculated by the formula fits very well to the data currently used in clinics with the maximum error less than 1% and probable error of about 0.1%-0.3%. Using this formula can overcome the time-exhausting work in measurement of PDD and TAR. 相似文献
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我区地处山区和深丘陵地区,水田较多且为常年积水的冬水田。泥脚深、泥土稀软;田块小,形状不规则;田间高差大,道路窄小崎岖。为实现机械化作业,我所自1969年开始研制机耕船。第一代样 相似文献
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