Mixture G4Material, optical properties?

I try to create a mixture G4Material consisting of 2 components with defined optical properties (I used SetMaterialPropertiesTable method). But the resulting material hasn’t any optical property. Is it possible to inherit the optical properties of the resulting material from its components using methods of Geant4?

No. Each material (G4Material*) has its own G4MaterialPropertiesTable. For your mixture, you will need to define the appropriate optical properties and attach the properties table to the new G4Material* you have created.

Thanks for your help! But the problem is that the optical properties of the new material are unknown, I have only the properties of the components. Maybe is there a way to simulate the mechanical mixture of the micrograines with no chemical bonding? Maybe is it possible to do it using a special geometry build?

I think you’re going to need to find some other kind of software for that (I wonder if Comsol has modules to compute optical properties?). Geant4 can’t simulate either the chemistry or the material processing to compute optical properties from first principles.

Geant4 specifically simulations the transport of radiation (high energy particles) through matter; the matter is treated entirely as a continuum with uniform properties. For high energy interactions (like ionization energy loss), the average behaviour is just a well-defined composition of the material’s components (Zeff, Aeff, density, etc.), but not for optical properties: those depend on the detailed microstructure of the material.

If I give you a bag full of sand and borax, it’s not going to be a transparent crystal with index of refraction 1.3. But to Geant4, it’ll have essentially the same dE/dx, neutron scattering, and activation properties as borosilicate glass. Heck, if I give you a bag full of crushed glass frit, it won’t have the same optical properties as a block of glass!

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