A neutron detector system, with a detector having a pair of spaced diamond detector layers, sandwiched between outer silicon layers. In response to incident neutrons, the detector system measures pulse heights and response times, and from those measurements, calculates the carbon recoil energy and time of flight of scattered neutrons. This data is further used to calculate a direction cone, which represents the approximate angle of arrival of the incident neutron. These direction cones can be used to image neutron events.

A neutron detector system, with a detector having a pair of spaced diamond detector layers, sandwiched between outer silicon layers. In response to incident neutrons, the detector system measures pulse heights and response times, and from those measurements, calculates the carbon recoil energy and time of flight of scattered neutrons. This data is further used to calculate a direction cone, which represents the approximate angle of arrival of the incident neutron. These direction cones can be used to image neutron events.

In accordance with embodiments of the invention, at least the potential presence of Special Nuclear Material (SNM) is determined by the detection of prompt neutrons, prompt gamma rays, delayed neutrons, and/or delayed gamma rays from photofission, via time-of-flight (TOF) spectroscopic methods. Methods and systems are disclosed.