CAJ | 학술논문

在高能闪光照相技术中,提高图像接收平面上直穿与散射的比值有利于有效信息的提取.利用蒙特卡罗方法对法国实验客体的照相过程进行模拟,得到图像接收区域直穿分量与散射分量的能谱分布,依据其分布的特点提出了利用能谱优化来提高接收区域直散比的方法,指出添加衰减屏可以达到能谱优化的效果.依据线吸收系数的变化趋势以及实际加工的难度选择钽作为优化能谱的材料,并根据最小照射量的限制得到了最大的衰减屏厚度.最后通过蒙特卡罗模拟,指出添加9 mm的衰减屏能够对照相结果的优化程度最好,照射量满足要求,而直散比上升到原来的3倍左右.
재고능섬광조상기술중,제고도상접수평면상직천여산사적비치유리우유효신식적제취.이용몽특잡라방법대법국실험객체적조상과정진행모의,득도도상접수구역직천분량여산사분량적능보분포,의거기분포적특점제출료이용능보우화래제고접수구역직산비적방법,지출첨가쇠감병가이체도능보우화적효과.의거선흡수계수적변화추세이급실제가공적난도선택단작위우화능보적재료,병근거최소조사량적한제득도료최대적쇠감병후도.최후통과몽특잡라모의,지출첨가9 mm적쇠감병능구대조상결과적우화정도최호,조사량만족요구,이직산비상승도원래적3배좌우.
In high energy flash radiography, enhancing the direct-to-scattered ratio(DSR) in receiving plane is favorable to the derivation of effective information. Monte-Carlo method is used to simulate the radiography process of French test object(FTO). Energy spectrum distribution of direct and scattering fluxes is obtained within the receiving domain. The method to improve the DSR in the receiving domain by energy spectrum optimization is proposed according to the distribution property. It is found that energy spectrum can be optimized by inserting an attenuation screen. Owing to its low absorption coefficient, tantalum is adopted as the material to optimize the energy spectrum with concerning practical manufacture condition. The maximum thickness of the attenuation screen is derived according to the minimum radiation dose. The Monte-Carlo simulation shows that the 9 mm tantalum attenuation screen can best optimize the radiography results, the radiation dose is sufficient and the DSR can be raised to three times higher.