These have included passive gamma ray spectrometry, passive and active neutron coincidence counting and neutron multiplicity measurements.

Helium splits out, and a neutron comes out and lots of energy comes out.

(c) Photo neutron interrogation photo induced neutron emission occurs when the energy of an incoming photon (X ray or gamma ray) is above a certain threshold and atoms of low atomic weight undergo photonuclear reactions that emit neutrons.

This applies to such techniques as gamma ray spectroscopy, passive gamma imaging and neutron multiplicity analysis.

In the first situation, an approved fissile materials container without external marking, but with a seal, is declared to be loaded with neutron emitting fissile material, and this is moved from a store, through a neutron detecting portal, which registers a positive. Here

But fortunately, if you can do this fusion reaction, you've got a neutron, so you can make that happen.

And you make if from lithium. That reaction at the bottom, that's lithium 6, plus a neutron, will give you more helium, plus tritium.

The power of these magnets, the power of what we can do here, is that we can see an individual neutron with this technology.

Materials such as deuterium or beryllium used in some nuclear warheads in association with fissile material may be detectable by using the photo neutron technique.

One Israeli Knesset member allegedly stated that Israel had dropped neutron bombs containing fissile material in the area along the Golan that separated Israel from Syria.

Analytical work has been carried out in order to calculate the detection probabilities of various gamma and neutron sensors and to learn how to combine them into distributed networks.

And that's because we're measuring the weight so precisely that carbon comes in different isotopes, so if it has an extra neutron on it, we actually measure it as a different chemical.

(a) Passive auto radiography using digitizing phosphor image plates (gamma type and neutron type), in conjunction with a pin hole collimator, to record images of objects of interest, using their own radioactive emissions.

The observations have also revealed the presence of a third planetary body, with a mass only 1.5 percent that of the Earth, that orbits the central neutron stars at a distance of only 0.2 astronomical units.

So, again, this is stuff we're doing with Danny Hillis and a group called Applied Proteomics, where we can start to see individual neutron differences, and we can start to look at that system like we never have before.

In particular, the hardware advances in rapid neutron detection arrays and active time of flight probing techniques have been a recent focus of attention, as have the various post data acquisition analysis and modelling methodologies that are under development internationally.

If placed in close proximity to an object emitting neutrons, or its container, the foil may be activated sufficiently that radio spectroscopy of resulting activation products in the foil could yield low fidelity information on the nature of the neutron flux.

In the second situation, an approved fissile materials container without external marking, with a seal, and a tag identifying the unit type contents, is declared to be loaded with a neutron emitting fissile component, and this is moved through the same portal detector, which registers a positive. Here

In order to study it, it has been decided to build the International Fusion Materials Irradiation Facility (IFMIF) in Japan. Some scientists have argued that the neutron irradiation in IFMIF won t be the same as in fusion reactors, but it should be noted that its cost, at one billion euros, will be one tenth that of ITER.