Carinou E, Kamenopoulou V, Stamatelatos I E
Greek Atomic Energy Commission, Agia Paraskevi.
Med Phys. 1999 Dec;26(12):2520-5. doi: 10.1118/1.598787.
MCNP code was used to simulate neutron and prompt gamma ray transport for a range of maze geometrical parameters, wall composition, and wall surface lining. Verification measurements were performed at two medical electron accelerator facilities. A very good agreement was observed between the results of the measurements and the MCNP simulation. MCNP code results were compared with the results of analytical equations used for the calculation of maze effectiveness, derived by Kersey and McCall. A good agreement exists between the simulation results and the results of the analytical methods for maze lengths longer than 8.5 m. However, the results of the present study showed that for shorter maze lengths, Kersey's method tended to overestimate neutron dose at the door entrance, whereas McCall's method with the neutron room scattered correction applied, showed an underestimation of neutron dose. Furthermore, according to MCNP simulation results, the use of barytes concrete instead of standard concrete as room shielding material, reduced neutron dose at the door entrance by about 20%. Finally, it was shown that lining with layers of wood and borated polyethylene significantly reduced the neutron dose at the door entrance by 45% and 65%, respectively.
使用MCNP代码对一系列迷宫几何参数、墙体组成和墙面衬里的中子及瞬发伽马射线输运进行了模拟。在两个医用电子加速器设施处进行了验证测量。测量结果与MCNP模拟结果之间观察到非常好的一致性。将MCNP代码结果与Kersey和McCall推导的用于计算迷宫有效性的解析方程结果进行了比较。对于长度超过8.5米的迷宫，模拟结果与解析方法的结果之间存在良好的一致性。然而，本研究结果表明，对于较短的迷宫长度，Kersey方法往往会高估门入口处的中子剂量，而应用中子室散射校正后的McCall方法则显示出对中子剂量的低估。此外，根据MCNP模拟结果，使用重晶石混凝土代替标准混凝土作为房间屏蔽材料，可使门入口处的中子剂量降低约20%。最后，结果表明，用木材层和硼酸化聚乙烯衬里分别可使门入口处的中子剂量显著降低45%和65%。
