Systems and methods for generating X-rays and neutrons using a single linear accelerator are disclosed. Such system and methods may interrogate an object at times with X-rays and at other times with neutrons, e.g., after suspicious material is detected based on the X-rays. A system may include a single linear accelerator for generating first and second electron beams; first and second targets; a magnet configured to control irradiation of the first and second targets by the first and second electron beams; and a controller that (a) causes the linear accelerator to generate the first electron beam and causes the magnet to direct the beam to first target to generate X-rays; and (b) causes the linear accelerator to generate the second electron beam and causes the magnet to direct the beam to the second target to generate neutrons.