Recent content by vengeance123

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    Deriving the critical radius of Uranium using diffusion equation

    Help Please!
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    How Is the Critical Radius Determined in Nuclear Chain Reactions?

    Thanks but i have already figured that out. When i set the density at the surface to 0, i get kr=m*pi, i know this is heading towards the correct answer because the answer is of the from r=pi*sqrt(D).
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    How Is the Critical Radius Determined in Nuclear Chain Reactions?

    Homework Statement I am trying to solve the diffusion equation for a sphere of fissile material. I then have to derive an expression for the radius above which a chain reaction will occur (the critical radius). . My trouble then, is finding a boundary condition other than at the surface of...
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    Deriving the critical radius of Uranium using diffusion equation

    maybe i should add a little more to this. The time dependence part of the neutron density is found to be exp(B-K)t where K=k*k (k is the separation constant). now at the critical radius i know that the neutron density cannot be increasing or decreasing with time (it must be stable). So i...
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    How Many Molecules from Julius Ceasar's Last Breath Are in Your Latest Breath?

    I had a similar question about king arthurs cup and the water in it and the molecules of it going around in my body etc etc. what you have to do is estimate the volume of air in the Earth - forget about the fact that air thins with altitude, just improvise. then just use the fact that most air...
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    Deriving the critical radius of Uranium using diffusion equation

    Homework Statement I have solved the equation for the neutron density as a function of position and time. I need the boundary conditions to change my infinite number of solutions (the varying separation constant) into one value so that my answer for the critical radius does not contain a...