The basic principle and method of neutron detection of possible explosives are introduced in this paper. A neutron generator

sized at Φ76 mm×1100 mm

is designed at CIAP. For installing an α particle detector in the generator

the Penning ion source is applied with high voltage and the target is grounded. In order to improve the detector efficiency

the ion beam incidence to the target is 45°. The test results show that the generator has good stabilization

and generator has been used for over 100 hours in the neutron output from 3×107 to 5×107 n/s.