How to implement specific materials (like PUR and paper)?

Geometry, Fields and Transportation
1

Hi,
I need to implement a material which is PUR but I’m not sure how to do this in Geant. From the manufacturer I don’t know anything more specific about the material than that it is PUR and the density (1.8 kg/m³).
The same remains open for so-called phenolic paper.
How would you handle this? Thanks a lot in advance!

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There are many forms of polyurethane and densities range from 0.05 to 1.7 g/cc. The chemical composition of PUR foam is C27H36N2O10, so you could build your own material using that formula with the appropriate density. (I looked all this stuff up quickly, so you should verify it.)

Phenolic paper is more of a challenge. The Wikipedia article says it is made of wood fibers and phenolic polymers. Wood fibers are basically lignin (C18H13N3Na2O8S2) but there are many phenolic resins. A common one is phenol formaldehyde polymer (C8H6O2). You could make a 'paper" material using lignin, and a ‘phenolic resin’ material using phenol formaldehyde polymer. Then you could make a ‘phenolic paper’ material by combining the previous two materials with the appropriate mass fractions and the appropriate density (~1.35g/cc?). However, I do not know the mass ratio of the two materials in phenolic paper or even if there is a single ratio.

The exact ratio and compositions may not be critical for either material, depending on your application. What exactly is it?

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Thanks a lot for the detailed input! I’ll look more into detail and verify it but it sounds good enough, so far.

The application is to determine the transmission through this material. Well, actually it is more like how much radiation will be detected behind it but this is like the same question, one could say.

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The latest version of PNNL’s “Compendium of Material Composition Data for Radiation Transport Modeling”, PNNL-15870 Rev2, has data for PUR and phenolic resin paper under the tradename Bakelite. Whether these are exactly the materials you are using is debatable, but it’s a start and it may not be critical. Get the compendium at https://www.osti.gov/biblio/1782721 .

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