Using four nuclear reactions as neutron source, the relative efficiency of BF3 long counter in the neutron hall of 4.5 MV Van de Graaf accelerator at Peking University was calibrated.

• 本工作采用4种不同的核反应作中子源，对北京大学4.；5 MV 静电加速器中子实验大厅的BF3长计数器的相对效率进行了刻度。