4 ms·

A fizzle of the (relatively small, fission) primary would be some percentage of a number much lower than 4 megatons. Most of that "oomph" comes from the fusion

by jlgreco 13y ago

A fizzle of the (relatively small, fission) primary would be some percentage of a number much lower than 4 megatons. Most of that "oomph" comes from the fusion secondary which is set off by the primary detonating as designed. I don't know how big the primary on that bomb was, and can't find anything about that, but did find this (http://en.wikipedia.org/wiki/Castle_Koon http://en.wikipedia.org/wiki/Castle_Koon) test of a fusion bomb where the primary didn't fizzle but the secondary nevertheless did not ignite. The primary there was 110 kilotons. So the primary on that bomb, not fizzling, is around 5 or 6 Nagasaki blasts.

ballard 13y ago
How much energy is yielded by "fusion" secondaries ([1st]fission - [2nd]fusion-fission) varies by design, but secondary's fusion is used for more efficient (eg more complete) fission. Only huge bombs have tertiary fusion stages that contribute much more yield than fission stages. http://en.wikipedia.org/wiki/Teller-Ulam_design http://en.wikipedia.org/wiki/Teller-Ulam_design
- jlgreco 13y ago
  I'm not sure what you mean, the W39 was a Teller-Ulam design bomb. It wasn't a boosted fission bomb (though maybe the primary was? I don't know). I believe the Castle bombs were as well.
  - ballard 13y ago
    Edited to make sense with correct terms. Thanks.
  - tanzam75 13y ago
    The W39 is a revision of the Mark 15. According to Wikipedia, the Mark 15 had a real thermonuclear second stage that generated significant yield. However, its second stage was also packed with enriched uranium, and it obtained most of its energy from fission. Essentially, it was a two-stage thermonuclear weapon that had a lower fusion fraction than most two-stage weaopns. Summary of atomic weapons: 1. Pure fission. Fusion contributes 0% of yield. 2. Boosted fission: Fusion is used solely to improve the explosive yield of the fission. Fusion contributes 1% of yield. 3. Dirty two-stage thermonuclear: Fusion contributes between 1 and 50% of yield. Most of the yield comes from fissioning of the U-238 tamper by fast neutrons. 4. Clean two-stage thermonuclear: Fusion contributes 90-99% of yield. The U-238 tamper is replaced with beryllium or lead, which does not undergo fission when hit with fast neutrons. 5. Three-stage thermonuclear: Same as two-stage. Thermonuclear bombs are considered to be an "unlimited" design, because you can keep stacking stages on top of each other, until you've got enough to blow up the planet.

by jlgreco 13y ago

ballard 13y ago

How much energy is yielded by "fusion" secondaries ([1st]fission - [2nd]fusion-fission) varies by design, but secondary's fusion is used for more efficient (eg more complete) fission. Only huge bombs have tertiary fusion stages that contribute much more yield than fission stages. http://en.wikipedia.org/wiki/Teller-Ulam_design http://en.wikipedia.org/wiki/Teller-Ulam_design

jlgreco 13y ago
I'm not sure what you mean, the W39 was a Teller-Ulam design bomb. It wasn't a boosted fission bomb (though maybe the primary was? I don't know). I believe the Castle bombs were as well.
- ballard 13y ago
  Edited to make sense with correct terms. Thanks.
- tanzam75 13y ago
  The W39 is a revision of the Mark 15. According to Wikipedia, the Mark 15 had a real thermonuclear second stage that generated significant yield. However, its second stage was also packed with enriched uranium, and it obtained most of its energy from fission. Essentially, it was a two-stage thermonuclear weapon that had a lower fusion fraction than most two-stage weaopns. Summary of atomic weapons: 1. Pure fission. Fusion contributes 0% of yield. 2. Boosted fission: Fusion is used solely to improve the explosive yield of the fission. Fusion contributes 1% of yield. 3. Dirty two-stage thermonuclear: Fusion contributes between 1 and 50% of yield. Most of the yield comes from fissioning of the U-238 tamper by fast neutrons. 4. Clean two-stage thermonuclear: Fusion contributes 90-99% of yield. The U-238 tamper is replaced with beryllium or lead, which does not undergo fission when hit with fast neutrons. 5. Three-stage thermonuclear: Same as two-stage. Thermonuclear bombs are considered to be an "unlimited" design, because you can keep stacking stages on top of each other, until you've got enough to blow up the planet.