dr. canavan: that is a good question. i covered that a little in my testimony. shielded not easily from inspection by neutrons. if you keep the neutrons fast enough, with high enough energy, they are not affected eye absorbers -- by absorbers. neutrons can go through a whole ship without slowing down. is what ispart called moderators, things that reduce the energy of the neutrons. in a bunchas packed of moderator materials, carbon or something, it could slow neutrons. enough of it could slow the neutrons down enough to where not enough of them would penetrate into the core to give you a good nuclear signature. it is not a precise number, but a foot or so of carbon outside of the device may be could affect that sort of slowing down. there are 2 things to consider. one, by the time that you have a few feet of carbon on either side of the device, you have blocked the whole container it is in. that it itself would be a signal that someone had tried to do this. it is not an easy thing to do. the other thing is a technical point, but when neutrons bounce off of a mode

dr. canavan.iggest issue that everyone tells me while we can't have 100% scanning is that in some way that would impede, slow down commerce, and we just can't afford that. i do have a bill that would provide grants to two ports in this country that would voluntarily decide to government 100% scanning with the technology that we have available just to i sort of want to prove to everybody wrong actually we can do this and not impede commerce in a way that would really impact the economy. but is there technology of that that you spoke about, which one of those technologies could work, and also not impede commerce? >> well, there's sort of, there's one technology i talk about that's interrogation with neutrons. i think he would fill the requirements of you are sort of setting down there. i always kind of like, have these heavy cranes that move things around. i would like to put my little source on one leg of the thing at the detector on the other. while it's moving around, plenty of time. it does insp