快中子活化法对声空化核效应的验证

采用纯铜作为阈探测器检测声致核聚变产生的14 MeV中子。根据14 MeV中子与Cu的核反应，选择合适的放射性核素及其特征γ峰作为测量依据。中子辐照时间为50 min，经30 min和198 min冷却，NaI探测器分别测量了超声和非超声下活化铜片的511 keV特征γ峰计数，测量结果显示，采用短冷却时间可测得⁶²Cu的511 keV γ特征峰，γ峰净面积计数增量ΔC均为正值，具有统计意义，在声空化条件下核反应液体中D-T反应产生的14 MeV中子发生率大于在非声空化条件下的；采用长冷却时间可测得⁶⁴Cu的511 keV γ特征峰，ΔC均为正值，具有统计意义，在声空化条件下核反应液体中D-D反应产生的2.45 MeV中子发生率大于在非声空化条件下的。由此验证了声空化核效应（NEAC），并初步分析了中子成核声空化核效应的机制。

Verification of Nuclear Effect of Acoustic Cavitation Using Fast Neutron Activation Method

14 MeV neutrons originated in acoustic cavitation fusion were determined using copper threshold detector. According to the nuclear reaction of 14 MeV neutrons with copper, the characteristic γ peaks of some radioactive nuclides were measured and the activation parameters of Cu were optimized. With neutron irradiation time of 50 min, 511 keV characteristic γ peak counts of activated copper pieces with or without ultrasonic field after 30 min and 198 min were respectively determined by NaI detector. Measurement results show that the characteristic γ peak counts of ⁶²Cu and ⁶⁴Cu can be respectively determined after 30 min and 198 min. 511 keV characteristic γ peak net count increments are positive values and statistical significance, which indicates that 14 MeV and 2.45 MeV neutron generation rates originated in fusion with ultrasound are greater than that without ultrasound in nuclear reaction liquid. These results verify the nuclear effect of acoustic cavitation (NEAC). The mechanism of NEAC nucleated by neutrons was proposed initially.