Metal Foam Found to Block X-Rays, Gamma, Neutron Radiation (Stephen)

The following comment was posted by Stephen on the Always Open thread.

There is an interesting article in Space daily about the use of metal foam to absorb radiation:

[From the article:

“Research from North Carolina State University shows that lightweight composite metal foams are effective at blocking X-rays, gamma rays and neutron radiation, and are capable of absorbing the energy of high impact collisions. The finding means the metal foams hold promise for use in nuclear safety, space exploration and medical technology applications.”]

It seems all kinds of radiatio n are affected including gamma, beta and neutrons but especially low energy gamma
It seems this material is more effective than solid material of the same weight at absorbing the radiation,
I wonder is it simply the increased volume that is having an effect or is there something about the structure that is increasing the absorption with these kind of materials. It seems to me from the article that the later is the case.

If so, I wonder about what mechanism is at work. Could it be that that the structure is some how increasing the probability of absorption by diffraction effects etc or is it something more to do with the way the material interacts with the radiation perhaps leading to evanescent waves on appropriately aligned surfaces, resonance effect and generation SSP etc.

Could the nano structure in LENR devices behave in the same way and if so could radiation in these devices be absorbed by this process?

  • Stephen

    Lou Pagnucco at the LENR Forum has also raised an interesting post on this material there:

    His post has a lot of additional links that are interesting.

  • Stephen

    Also interesting and possibly relevant in this context is this other post in Space Daily. I think Axil will like this one:

  • Stephen

    One small correction to my post. Beta radiation was not included in the space daily article just Gamma, X-rays and neutrons. I’m now curious if Beta would also be affected and if it was also tested.

    • Ged

      Beta is blockable by a sheet of paper, or even your outer dead skin layer. It is only dangerous if a beta source gets inside you or otherwise gets to exposed soft tissue. Since it is so trivial, it doesn’t bear mentioning as of course the material blocks it.

      • Stephen

        Good Point 🙂 Thanks Ged

        • Ged

          This is a really cool discovery with a whole host of awesomely useful implications (and for LENR too). Thank you for sharing the news 😀

  • Gerrit

    The authors haven’t proposed a theoretical explanation, just observation.

    We must adapt Huizenga’s a priori reasoning: “Furthermore, if the claimed attenuation exceeds that possible by other conventional processes (lead shielding), one must conclude that an error has been made in measuring the attenuation.

    • Job001

      Huizenga was illogical and biased assuming two particle physics non-condensed matter physics was useable rather than statistically undeniable experimental results for condensed matter physics conditions. Huizenga’s assumptions were bad assumptions.

      • GreenWin

        Huizenga represents the grave damage caused by data bias and microcephalic thinking.

        • Agaricus

          He gives new meaning to the phrase ‘political scientist’. A professional ‘debunker’ of the most destructive kind.

  • Observer


    For the same reason foamed glass would have lower visible transmission than solid glass; lensing causing dispersion causing a greater mean path length traveled through the medium and a greater possibility of reflection.

    It would be interesting to se if there is a correlation between the index of refraction of a given wavelength in a given metal and the reduction in transmission.

    • Agaricus

      Yes, that does seem the most likely explanation. Lensing and reflection will obviously be random within a foam, and perhaps a compound metallic absorber could be designed in such a way that radiation is bounced around in a path predominantly at a steep angle to the line of entry, to maximise the path it has to travel – perhaps to a length that is many times the thickness of the shielding.

    • Gerard McEk

      I can understand that in case of gamma rays, but if you have neutrons, than that seems to be a strange explanation. I think there is more going on.

      • Agaricus

        Neutrons can be ‘reflected’ (scattered) as they encounter a boundary layer, in a similar way to EMR, but a difference of degree would be expected.

        • Stephen

          Thanks Peter those are great links. I had no idea that neutrons could be reflected and scattered this way. I wonder if RAL are taking a look at LENR? If they took up the challenge I’m sure with their expertise and equipment that their data and insights would be amazing. I wish we could see that kind of involvement and data.

        • Gerard McEk

          Thanks Agaricus, I was not aware of this. I wonder why this is not used more in the nuclear industry.

          • Agaricus

            It is a bit odd that such a simple phenomenon hasn’t been picked up and employed for radiological shielding. Just a case of engineering inertia I suppose.

    • Stephen

      Yup and looking at the foam structure in the article it contains spherical bubbles which give all kinds of angles for refraction and defraction. If so this has amazing implications for shielding. It with the right angle of refraction it could lead to evanacent waves over a surface which I understand can lead to some of the other effects I mentioned.

      . I wonder if a finer or denser foam would also have greater effect or if this would also depend on the wave length

  • Paul

    Very strange that University of North Carolina is doing research in this field. Perhaps the E-Cat technology is not so safe as many tell in public…

    • Agaricus

      An interesting and slightly desperate slant on this snippet. The reasons for the research are given in the article: “…. hold promise for use in nuclear safety, space exploration and medical technology applications” – nothing to do with e-cat at all, as I’m sure you are well aware.