CAJ | 학술논문

冷中子三轴谱仪( CTAS )的屏蔽体对于保障工作人员安全、降低散射大厅本底及提高信噪比具有重要的意义.采用蒙特卡罗程序MCNP5对谱仪各部分屏蔽体进行了计算,并结合Mcstas程序确定了CTAS入口处的中子源,大大提高了计算效率.经过模拟计算和优化表明:单色器后端使用厚350 mm、密度4.6 g/cm3的重混凝土,衔接屏蔽体使用厚300 mm、密度3.6 g/cm3的重混凝土,生物屏蔽采用厚150 mm、密度3.6 g/cm3的重混凝土可保证屏蔽体外表面的剂量率满足散射大厅的剂量要求.
랭중자삼축보의( CTAS )적병폐체대우보장공작인원안전、강저산사대청본저급제고신조비구유중요적의의.채용몽특잡라정서MCNP5대보의각부분병폐체진행료계산,병결합Mcstas정서학정료CTAS입구처적중자원,대대제고료계산효솔.경과모의계산화우화표명:단색기후단사용후350 mm、밀도4.6 g/cm3적중혼응토,함접병폐체사용후300 mm、밀도3.6 g/cm3적중혼응토,생물병폐채용후150 mm、밀도3.6 g/cm3적중혼응토가보증병폐체외표면적제량솔만족산사대청적제량요구.
The shielding of Cold neutron Triple-Axis Spectrometer( CTAS ) is important for radiation safety of workers, and reduce the background of scattering hall as well as enhancing the ratio of signal-to-noise. In this study, Monte-Carlo simulation was performed to conduct the calculation on the shielding of CTAS. To increase the calculation e?ciency, neutron source was obtained by using Mcstas code. The results indicate that, in the case of heavy concrete ( density 4.6 g/cm3 ) with thickness of 350 mm for the shielding behind the monochromater, and heavy concrete ( density 3.6 g/cm3 ) with thickness of 300 mm for the other monochromater shielding, as well as the heavy concrete ( density 3.6 g/cm3 ) with thickness of 150 mm for biological shielding, the dose rate outside shielding may meet the requirement of national standard of China.