I'm out of the desert now, just returned from the SIMNUKE event commemorating 60 years since the first detonation of a nuclear bomb on July 6, 1945. Here is a hastily gathered set of snapshots. More to come. Stay tuned for an NPR "Xeni Tech" report airing on "Day to Day" Monday morning, and for more pics and video.
Image: At around 3:15am Saturday July 16, Dave Bayer of the Simnuke production team is hurriedly scraping ice off a large nitrogen tank. As nitrogen leaves this tank, and travels by hose to propel fuel in the fuel tanks, a condensation effect occurs, and ice forms. This is bad, because it slows down the nitrogen flow, making it harder to fill all the fuel tanks on time for the scheduled 5:29AM blast.
Previously: Xeni headed to Simnuke
Update: photographs from SIMNUKE participant William Francis, including the image below, are here.
Boing Boing reader Allen Knutson says:
You didn't mention the condensation on the hose itself, which is much more impressive. First the hose looks wet, then looks dry, then looks wet again. Why?
First water condenses on it. Then water freezes on it. Then *oxygen* condenses on it. After a while the oxygen can even pool enough to drip off. Drip, drip.
(It's not cold enough to freeze oxygen, or, of course, condense nitrogen.)
Reader "Foxy Hedgehog" adds,
Maybe you've seen these. Robert Longo's exquisite and indelible drawings of the early detonations. The first chapter in this history. Link 1, Link 2, Link 3.
Tom Arey says,
A group of amateur radio operators commemorated the Trinity tests at the original test site by way of a special events station. Link. Also, a lot more information on the Trinity event can be found at the White Sands Missile Range Site: Link.
(Ed Note: link also has details on an "open house" event which took place at the range site on July 16 to commemorate the 60-year anniversary.)
UPDATE: Dave Bayer, the SIMNUKEr shown in the photo at the top of this post, says:
Slight correction (as I was probably not the easiest person to get to talk to in the desert): The large tank has liquid nitrogen in it. We stored pressurized gaseous nitrogen in the fuel tanks to later propel the fuel (doing so with liquid nitrogen would be very dangerous with the tanks and fittings in use due to the extreme cold and its effects on rubber and steel). Liquid nitrogen sits at about -193C in that tank. To evaporate the liquid nitrogen and warm the resulting vapor, the dewar (the nifty stainless steel tank covered in snow in the photo) has coils close to the surface to pull in heat from the surrounding environment. The layer of frost slows heat transfer into those coils which reduces the rate at which we can pull warmed vapor out of the dewar. Not enough heat and too high a flow rate results in very cold vapor or even liquid being drawn from the vapor port on the dewar.
Once the ice was scraped, there was a cascade of fog around the dewar like opening a refrigerator /freezer door on a humid day.
Ok, probably too much information (but I am a little anal about information seeing as one part of this wass an educational project) which can/should be distilled and condensed to something like: As gaseous nitrogen leaves this tank to be stored to propel the fuel later, the boiling of liquid nitrogen chills the outside of the tank causing a condensation effect. This is bad because it slows the flow rate at which the nitrogen can safely be pulled from the tank, making it harder to fill all the ...