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    Neutron absorption cross section

    This place works for me:
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    Photon buildup in shielding

    Who do you believe? I'm doing some shielding calcs for Cs-137 (662 KeV gamma) in stainless steel (Fe seems close enough) with ux (mfp) in the range of 5 to 15. Shultis and Faw in Radiation Shielding (2000) treat Photon buildup pretty well. Their coefficients for the Berger...
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    NERVA radiation emissions

    Besides exhaust, when operated in an atmosphere, there's the problem of backscattered radiation (both gammas and neutrons) from the reactor reaching the payload/crew compartment. It's not just line of sight - radiation that escapes the reactor will scatter in any surrounding structure and...
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    Fourth Generation Nuclear Weapons

    Hadn't heard of these. All mine sort of fade out once they've been comptonized a bit and then photoelectronized. A particular spectrum of gamma rays? Photoneutron production maybe? Gamma rays produced by thermal sources? (not just really high energy x-rays) I've not thought of gamma...
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    Ba-133 neutron capture

    Raw material is barium carbonate, BaCO3, 196g/mole hence the 1.2E20 atoms of Ba-132, which makes it even longer. 1.77E18 of Ba-133 is what I had. Cross section for Ba-132 is 9 barns which would give the 5 weeks (they run 6.5 days a week from what I understand), not counting the conversion of...
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    Will there ever be nuclear powered cars?

    I don't think you need all that much energy for a car, and even a semi is only an order of magnitude greater. Safe bet that storage will always be easier than generation, though the lines tend to blur, (e.g., fuel cells, with fusion being a deuterium fuel cell). Isomer energy storage would...
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    Ba-133 neutron capture

    That's the thing I love about this stuff - scientific notation. The equilibrium ratio 9 to 4, is way more to us, but when we're talking 1.2 10E20 atoms of Ba-132 (in 100 mg Barium carbonate enriched to 40%, natural Barium has only .1% atoms of Ba-132) that gets us to 2.7 10E20 which just...
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    Ba-133 neutron capture

    Thanks! Good table. Cross sections for all the energies is a plus. Was looking at making some 100 mCi Ba-133 sources from enriched Ba-132 in reactor. But with Ba-132 at about 9 barns you don't make much, and with Ba-133 not much smaller at 4 barns, you lose a lot of the Ba-133 you do make...
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    Ba-133 neutron capture

    Anybody have good values and a source for thermal neutron capture cross section for Ba-133, both ground and excited states? CRC Handbook gives 4 barns, but wanted to verify it. Thanks.
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    Nuclear waste to Electricity?

    I recall several studies on accelerator driven transmutation of nuclear waste with net excess of power being generated. Here's one I could find from LANL in 1993. ABSTRACT: "A medium energy, high current proton beam strikes a heavy metal target, producing a high flux of spallation neutrons...