The problem with such a small hand held neutron emitting device is penetration capacity. High energy neutrons are needed and necessary to penetrate materials that would cover explosive susbstances, like steel, concrete, aluminum...A small portable device is not feasible for the reason that the energy requirements and the sheilding necessary to protect the user would create too heavy a device.
Hi-energy technologies is currently has a working prototype but it is something that fits in the back of a van or small truck. I think some on this board have the illusion that ISON is working on a device the size of a PDA.
If ISON were seriously committed to this project, an investment of millions ($) instead of thousands would be necessary. I think the project is hype, and it is being utilized by the company to attract investment for its failing business.
That is a point you have brought to the attention of this board and I think it deserves to be investigated furthermore. You are correct in your assessment that high energy neutrons are required to penetrate steel. At this point, we need to give them the benefits of doubt, as being scientists and probably good engineers, they MUST have taken this security issue in consideration. I would expect they will elaborate more on that topic in the paper that will be released for the NATO meeting. We should be able to get a copy from the company after the meeting.