Low energy Photon Simulation in MCNP

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Simulating low energy photons in the wavelength range of 300 nm to 1000 nm is challenging in MCNP, as it primarily focuses on high-energy particle transport. However, since version 6.1, MCNP can simulate photons down to 1 eV, which corresponds to a wavelength of approximately 1.25 µm, by using the EPRDATA14 cross-section library. For tasks involving reflection and refraction, raytracing software like POVRay is recommended. Users seeking to analyze photon transport to a region of interest can specify material properties, including refractive indices, in MCNP. Overall, while MCNP has limitations, it can accommodate certain low-energy photon simulations with the right configurations.
Salman Khan
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Hi everyone.
is it possible to simulate low energy photon in wavelength range (300 nm to 1000 nm) in MCNP. If not possible in mcnp please suggest any other code to simulate it.
thanks
 
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MCNP goes down to 1keV, which is around 0.1 nm and in the soft X-ray region. This is a Monte Carlo simulation, so it runs scattering by using probabilities ruled by the physics, and random numbers. There is not a lot of overlap between these methods and visible light. There's no simulation of refraction or dispersion so I suspect it can't do what you want. - Edit, my information is out of date. Thanks to @DamienA for correcting this below.

300nm is in the UV through the visible to the NIR range at 1000nm. If by simulate you want to produce an image with reflection and refraction etc, then a raytracer like POVRay is a good choice. Actual physics simulation beyond these processes may be limited.
 
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Thanks Alex, I just want to see that this low energy photon will either reach or not to a region of interest I just want to see their transport
 
Hi, it's true that MCNP is a high energy particles transport code. However, since the release 6.1, it 's possible to simulate photon/electron of energy down to 1 eV (lambda ~1.25 µm) and specify a refractive index for materials (see page 307 on the mcnp6.3.0 user manual) . To be able to transport photons down to 1 eV, You should also specify the EPRDATA14 cross section library (which is not a default xsdir library). Calling such cross section is performed with the extension ".14p" . For instance, you can define water material as " m1 1001.14p 2 8016.14p 1 refi = 1.32 " to compute cerenkov light spreading.
 
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