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Simulation software for modeling a dusty fission reactor variant.

  1. Mar 21, 2014 #1
    Hi, all. Could anyone recommend some good software for modeling nuclear physics? I have concept nuclear rocket that I wanted to attempt to model the engine for to see how practical it would be.

    In case it's relevant:

    The design is a subcritical fast dusty fission fragment reactor driven by a spallation neutron source. The core is based around the current dusty fission fragment rocket proposals:


    That is, to say, electrostatically-suspended nanoscale fissile dust particles in a magnetic field which has little effect on the dust but focuses the emitted fission fragments either into a MHD grid for non-Carnot power generation or out a magnetic nozzle for high-Isp thrust, with heat managed via IR radiation due to the dust's huge surface area to volume ratio. However, said proposal is a slow reactor with a very heavy moderator around the reactor to increase the neutron flux; a fast reactor would dramatically reduce weight and make dealing with the high IR flux much easier.

    In addition to the weight advantage, without the need to be surrounded by a moderator, two new design options open up:

    1) having the reactor core open to space, allowing most of the IR to radiate out uninterrupted, greatly simplifying cooling; or

    2) having the reactor in a transparent sealed fused silica tube (fused silica blackens less under neutron bombardment than fused quartz, and neither lose much transparency in the IR spectrum) in the center of a mirrored nacelle. In this option, hydrogen or another gas could be injected (or, for atmospheric flight, air ducted in) into the nacelle and a small amount of it turned to plasma via microwave bombardment. The sheet of plasma would absorb the radiated IR from the core, heating the bulk gas moving through the engine and out a conventional nozzle on the far end. At low propellant flow rates, a magnetic nozzle could be used instead of a physical one, allowing for higher peak temperatures and a VASIMR-ish mode of operation.

    #2 is basically a "nuclear lightbulb" concept but without the need for a gas or plasma core and thus no need for impossibly-heat-resistant materials. And of course, it could still operate in a fission fragment rocket mode by opening up the core to space. Both variants could even potentially function as a photonic rocket. There's many potential modes of operation, running the full range from very high thrust to very high ISP.

    The #2 variant is more of a CFD simulation problem, but I think it's important to model the core first before working on any of the above. And if the goal is to get rid of the moderator, that means a fast reactor, and that means an external source of fast neutrons, and that means (until fusion becomes a realistic option) a spallation neutron source input. And that's the core I'd like to try to model. I'm especially curious whether the spallation could simply be from high energy (a few hundred MeV to a few GeV) ions accelerated straight into the core rather than against a target near the core.

    Anyway... any suggestions on software?
    Last edited: Mar 21, 2014
  2. jcsd
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