Sunday, July 6, 2025

U-Bomb: A Technical Prologue to Postblogging Technology, March 1955, II

 Yeah, well, I was tired yesterday and I needed to do some bike training (mainly wearing calluses into my tender tootsie) ahead of my summer bike trip, which is in July this year. That's why I'm talking about something that came up while I was half-finishing the March II postblogging.

The Special Report in the 7 March issue of Newsweek  covered the then-ongoing movie industry revival, and the 28 March issue has some letters about it, including a self-promoting but still valid explanation from Lester Rand of the Youth Research Institute (kids like going to the movies), and a letter from Zira Siegel of Culver City, California, pointing out how extraordinary this self-portrait with the Junior MGM Players, shot by Newsweek staff photographer Dale Healy is. Siegel asks whether it is a composite, and the Editor replies that it is not. Leslie Caron is 20ft behind the lens; Debbie Reynold is three feet away leaning in, and Pier Angeli is sitting on a pillow. 

Dean Schary doesn't even appear to have an online biography. He was just one of the anonymous staffers who made Newsweek, in spite of itself, a great magazine. And speaking of "in spite of itself," I first encountered the "U-bomb" in The Periscope, which feature, as was its way, got the whole thing so hilariously wrong that I was sent down the very productive rabbit hole that makes up most of this post. The U-bomb, it explains, means that the American atomic stockpile has been suddenly increased ten-fold, that there are enough bombs to "knock out the USSR with radioactivity," and that since the U-bomb "does not, (contrary to some reports) necessarily require a hydrogen bomb to set it off, the Soviets are in a position rapidly to overtake our lead." 

Don't get me wrong. I love The Periscope's serial incompetence. Made-up "should be true" news illustrates the era in ways that the a mere list of what actually happened, and ever since I learned that the writer was the publisher's son it has been my go-to example of nepotism ruining the American Republic. (For Britain I can just quote "Lord Salisbury" and ask which century this particular cabinet minister is from.) But you can see why I assumed that this had to be a description of the uranium hydride bomb until I hit  Science and learned that the story was some unnamed scientists outside of atomic secrecy pointing out that the well-publicised discovery of U-237 particles contaminating the deck of Lucky Dragon meant that the CASTLE BRAVO bomb had had a casing of depleted uranium to enhance its yield, and, incidentally, greatly increase its fallout production, although not as much as the "C-bomb." The story hit the press in connection with a weather system that stalled the eastward movement of the radioactive plume from the  TEAPOT test series over the Eastern United States, keeping radioactivity levels 40 times above background levels for a full week in early March. 

You'll see this picture in Postblogging. It is the test stand from
one of the 1953 uranium hydride tests in which the fizzle
was so small that it failed to "self-classify" by blowing up
the stand with its 200 ton explosion.  
Periscope is at least vaguely in the same room as "right" in saying that the implication is that the world's atomic arsenal is much bigger than previously calculated, if by this we mean yield. The U-Bomb really did seem to have the potential to hit 200 MT, and of course that whole line of research took us to the "Tsar Bomba" of 50MT yield, which can wait on its own post in the Technological Appendix series. Everything else is nonsense, as the whole point of the U-bomb as discussed this week is that it was a way of mopping up the surplus fast neutrons from the fusion component of a Teller-Ulam thermonuclear bomb. 

The uranium hydride bomb is another matter. First suggested by Oppenheimer in 1939 and championed by Edward Teller, it consisted of a core of uranium deuteuride (UD3, or in chemical terms, U2H3). The deuterium would act as a neutron moderator, slowing the neutrons and lowering the capture cross section, allowing a smaller amount of U238 to reach militarily-useful criticality and a smaller bomb with "radial compression" rather than the more complex spherical used in the Nagasaki bomb and all subsequent fission devices. In reality it turns out that damp fireworks fizzle. Who could have known? (Apart from James Conant, who worked it out in 1944.) 

The role of James Conant, by this time closer to the prime  minister of American science than a research worker is interesting, but as much so as that of Edward Teller at this point. For he, and Ernest Lawrence, now seized upon the uranium hydride device as the first avenue of development at the Lawrence Berkeley National Laboratory, the United States' other atomic arsenal. The failure of the RAY and RUTH devices therefore ought to have been a fatal blow for the institute's ambitions. They were particularly significant in that they were designed to be the cores of hydrogen bombs, Teller's other big thing. 

Of course, the failure of a decade of wasted  research didn't matter in the least. The whole matter was swept under the rug, perhaps because Teller and, as is too often forgotten, Lawrence, were willing to go along with Lewis Strauss' red-baiting campaign against Robert Oppenheimer. In defence of all that wasted effort, the Wikipedia article says that (these) "U-bombs" led to the SWAN device, the first two-point ignition hollow-pit air-lens implosion device. SWAN became the XW45, and then presumably the W45, which was widely used as a tactical atomic warhead and also caused some embarrassment when its unexpected deterioration in service required a  test series. 

Look, I'm sure Teller did something useful at some point besides flacking for Lewis Strauss. For example, the Livermore lab built the W27, the warhead used in the Regulus cruise missile. Er, wait, that's not a good example. Okay, they developed the W38, which went into the Titan, and yielded less than 4 MT, practically a love nip by Cold War standards. Maybe they put uranium hydride in modern bombs, like the only Livermore bombs still in service, the W87 and B83. Maybe modern bombs have all kinds of weird ingredients like transuraniums (besides plutonium) and U-233. I don't know! But this sure has been a Technical Prologue (Appendix) about nepotism and favouritism! 


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