Rolls-royce Corporation

Rolls-royce and Associates Limited

Martin J Allen

Peter A Stewart

Joseph Douglas

Peter H Fowler

Richard T Skelton

John D Rogers

Apparatus for non-invasively inspecting an object, such as an item of luggage, for explosives material comprises a multi-channel thermal neutron inspection system having a plurality of neutron irradiation chambers. Simultaneous operation of several channels increases maximum system throughout several times. Each chamber has a lithium neutron source which is stimulated to neutron production by a proton beam. Beam switching magnets are energized by pulsing to divert a common proton beam to each source in turn. The initial beam is generated by a radio frequency quadrupole accelerator. The advantages of this system are very low residual source activity and controllable neutron production thereby minimizing safety hazards. The irradiation chamber may contain several different gamma ray detectors to identify the presence elements present in explosives material. In addition a neutron radiography imaging means may be employed to identify the presence of potential shielding materials.

Explosives detector

Residual core material can be detected inside hollow cast articles using positron emission tomography. Positron radio-isotope material is inducted into any residual core material present by immersing a cast article in an aqueous solution of radio-isotope emitter, for example gallium. Absorbed gallium subsequently emits positrons which are annihilated in collisions with electrons emitting two 511 KeV gamma rays in diametrically opposite directions. The emissions are detected and tracked by a PET camera and the resulting images correlated with a sectioned image of the article as a check on the location of detected core material. Initially a low-dose-rate solution for the purpose of merely establishing the presence of core material is used but a second optional process step introduces a more active solution allowing a PET camera to collect sufficient data to image absorbed isotope.

Non-invasive inspection

Growing community of inventors

Bristol, United Kingdom

Martin J Allen