Adding a reflector to keep neutrons bouncing around longer, which I don't think was done in the original Little Boy weapon (the gun-barrel one), is a simple method of raising efficiency. The gun-type nuclear weapon is extremely simple to begin with; Manhattan Project researchers were so sure it would work they didn't test it, whereas they did feel compelled to try the implosion design, in the Trinity test. But for reasons I don't recall (which I think relate to neutron flux and neutron speed), the gun design works only with uranium, or at least is never used with plutonium.
By the way, the boosting method you referred to brings a spot of fusion into the picture, by way of deuterium and/or tritium. A mixed fission-fusion reaction isn't something you can get with a quantity of enriched uranium alone, which is what we began by talking about.
You may have hit on something there, as 100 pounds of highly enriched uranium would constitute less than went into the Little Boy weapon that exploded over Hiroshima, Japan, in 1945; judging from various online sources, that weapon contained about 64 kilograms of HEU, and 100 pounds amounts to only 45 kg. On the other hand, the design of the Little Boy weapon was (again, judging from online sources) highly inefficient. My rough guess is that 100 pounds of HEU would be enough for two or three weapons that employed an efficient design.
Networks don't drive social change; people do. This is akin to saying "guns don't kill--people do," a position that some find objectionable. But in both cases, it can make a difference what instruments are available. Social change, protest movements, and other forms of rebellion may be facilitated by one's network, whether it's the telephone network or Twitter; similarly (though this analogy is getting strained), a murderous rage can be facilitated by a handgun in the desk drawer.
Though I haven't read it yet, Malcolm Gladwell's article demands to be read--all of his articles do, in my experience--because he's probably saying something different, or at least more subtle, than that social media don't promote or drive change: that seems too obvious for him.
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Adding a reflector to keep neutrons bouncing around longer, which I don't think was done in the original Little Boy weapon (the gun-barrel one), is a simple method of raising efficiency. The gun-type nuclear weapon is extremely simple to begin with; Manhattan Project researchers were so sure it would work they didn't test it, whereas they did feel compelled to try the implosion design, in the Trinity test. But for reasons I don't recall (which I think relate to neutron flux and neutron speed), the gun design works only with uranium, or at least is never used with plutonium. By the way, the boosting method you referred to brings a spot of fusion into the picture, by way of deuterium and/or tritium. A mixed fission-fusion reaction isn't something you can get with a quantity of enriched uranium alone, which is what we began by talking about.
You may have hit on something there, as 100 pounds of highly enriched uranium would constitute less than went into the Little Boy weapon that exploded over Hiroshima, Japan, in 1945; judging from various online sources, that weapon contained about 64 kilograms of HEU, and 100 pounds amounts to only 45 kg. On the other hand, the design of the Little Boy weapon was (again, judging from online sources) highly inefficient. My rough guess is that 100 pounds of HEU would be enough for two or three weapons that employed an efficient design.
Networks don't drive social change; people do. This is akin to saying "guns don't kill--people do," a position that some find objectionable. But in both cases, it can make a difference what instruments are available. Social change, protest movements, and other forms of rebellion may be facilitated by one's network, whether it's the telephone network or Twitter; similarly (though this analogy is getting strained), a murderous rage can be facilitated by a handgun in the desk drawer. Though I haven't read it yet, Malcolm Gladwell's article demands to be read--all of his articles do, in my experience--because he's probably saying something different, or at least more subtle, than that social media don't promote or drive change: that seems too obvious for him.