易水湖水下天然中子测量

使用研制的以球形3 He正比计数器为中子灵敏元件的水下中子测量装置对易水湖水下1~25m范围内不同深度处的天然中子进行了测量,并结合相应的蒙特卡罗模拟,获得了易水湖水下不同深度处的低能天然中子产生速率和注量率随湖水深度的变化规律。结果表明:在易水湖水面下方1~10m范围内,低能天然中子产生速率c(cm~(-3)·s~(-1))随深度h(cm)呈指数规律下降,关系式为c=2.7×10~(-5)e~(-0.005 7h),10m以下的变化较为平缓。根据测量结果外推,在易水湖水面附近,水中低能天然中子的产生速率约为2.7×10~(-5) cm~(-3)·s~(-1)(或2.7×10~(-5) g~(-1)·s~(-1))。

Measurement of Underwater Natural Neutron in Yi Lake

The underwater natural neutron with different water depths from 1 m to 25 m in Yi Lake was measured by an underwater neutron measuring device which uses a spherical 3He proportional counter as the neutron sensitive component.Combining with some Monte Carlo simulations,the low energy natural neutron generation rate and fluence rate at different depths in Yi Lake were acquired.The results indicate that the low energy natural neutron generation rate (cm-3·s-1) varies as a rule of negative exponent of =2.7×10-5e-0.005 7h,when the water depth h(cm) is from 1 m to 10 m in Yi Lake.When the water depth is more than 10 m,the generation rate and fluence rate change slowly.Extrapolating from the results,the generation rate of the low energy natural neutron in water near the water surface of Yi Lake is about 2.7×10-5 cm-3·s-1(2.7×10-5 g-1·s-1).