中文摘要：

提出两种慢化体设计方案,第一种方案直接在原有慢化体中引入孔道,第二种方案在慢化体中增加一层铅之后再引入孔道.利用蒙特卡罗方法对两种方案进行研究.计算结果表明,采用第一种方案可以有效地提升C、O元素的测量精度,但同时会降低H、Si等元素的测量精度;采用第二种方案可提高C元素和O元素的测量精度,同时也可以提高H、Si等其它元素的测量精度.

英文摘要：

Two optimizing schemes of moderator are proposed. In the first scheme two channels are directly added to initial moderator, and in the second scheme two channels are introduced after adding a lead layer to initial moderator. Monte Carlo simulations are carried out for two optimizing schemes. It shows that the first scheme can improve measurement accuracy of carbon and oxygen, but it decreases measurement accuracy of other elements such as H and Si. In the second scheme, measurement accuracy of all elements can be increased as selecting proper thickness of lead and inclination of channels.