论文部分内容阅读
在GM-5半导体探测器对面放置一个~(239)Pu裂变源片,将此探头插入到零功率基准中心,测量堆中心绝对快中子通量。探头沿孔道可以精细到每隔5mm二个测点,得到活性区径向中子通量分布。采用~9239)Pu核作裂变靶是考虑到该核的快中子裂变截面对中子能谱不灵敏。而半导体探测器体积小,能插入到直径只有15mm的小孔道中。 用半导体探测器测量中子通量实际是记录~(239)Pu转换靶的裂变事件数。假定探测器的灵敏面对裂变靶片所张立体角为θ,则可探测到α粒子计数率为Aα
Place a ~ (239) Pu fission source across the GM-5 semiconductor detector, insert the probe into the zero power reference center, and measure the absolute fast neutron flux at the center of the stack. Probe along the tunnel can be fine to every two 5mm measuring points, get the radial flux distribution of the active zone. Using ~ 9239) Pu as the fission target takes into account that the fast neutron fission cross section of the core is insensitive to neutron energy spectrum. The semiconductor detector small size, can be inserted into the small diameter of only 15mm hole. The neutron flux measured by a semiconductor detector is actually the number of fission events recorded by ~ (239) Pu conversion target. Assuming that the detector faces sensitively to the solid angle at which the fission target is located is θ, the alpha particle count rate can be detected as Aα