3 ms·

> Producing even a little heat with fusion produces a lot of nasty radiation. As in kill everyone in the unsheilded room within a few seconds. This is greatly

> Producing even a little heat with fusion produces a lot of nasty radiation. As in kill everyone in the unsheilded room within a few seconds. This is greatly exaggerated. The amount of excess heat they claimed to observe was really quite small, and D-D fusion produces a relatively weak neutron flux [0]. I'm not saying some shielding wouldn't have been a good idea, but instant death? No. [0] https://en.wikipedia.org/wiki/Fusion_power#Deuterium https://en.wikipedia.org/wiki/Fusion_power#Deuterium

Retric 11y ago
100Mev+ X-Ray / Gamma radiation is not fun. There is some play in the numbers based on type of fusion, but ~1w is on the order of 10^12th reactions per second and flat out lethal. Sure, if a device is weak out 1 millionth of that then it's not a big deal, but nobody cares about 0.000001 watts / second.
- ScottBurson 11y ago
  You didn't even click the link. Neutrons from D-D fusion are at 2.45 MeV.
  - Retric 11y ago
    Yea, I was off by a factor of 10. https://en.wikipedia.org/wiki/Equivalent_dose https://en.wikipedia.org/wiki/Equivalent_dose 1W of 2.5Mev neutrons ~= 10W worth of Gamma Rays in terms of equivalent dose. (http://ocw.mit.edu/courses/nuclear-engineering/22-01-introduction-to-ionizing-radiation-fall-2006/lecture-notes/absorbed_dose.pdf http://ocw.mit.edu/courses/nuclear-engineering/22-01-introdu...) There are several 14.1+Mev fusion products see chart: https://en.wikipedia.org/wiki/Nuclear_fusion https://en.wikipedia.org/wiki/Nuclear_fusion (Which is probably where I was thinking 100Mev), but it’s already normalized so we are talking 10W equivalent. Granted that 10W dose equivalent is not focused so a person standing next to it might get 8% of that which is .8W, or ~0.01W/kg equivalent (for a 80kg person) which just happens to be ~1 Rads per second. (1 rad = 0.01 Gy = 0.01 J/kg. 250 to 500 rads is the LD/50. So, Standing next to an unshielded 1W neutron source has a 50/50 shot giving you a lethal dose within ~4 to 9 minutes. PS: 2.5Mev Neutron radiation @ 1J per kg is ~10 Gy which is ~LD100 and probably where I was thinking 1W = death. (Please double check my math.)

Retric 11y ago

100Mev+ X-Ray / Gamma radiation is not fun. There is some play in the numbers based on type of fusion, but ~1w is on the order of 10^12th reactions per second and flat out lethal. Sure, if a device is weak out 1 millionth of that then it's not a big deal, but nobody cares about 0.000001 watts / second.

ScottBurson 11y ago
You didn't even click the link. Neutrons from D-D fusion are at 2.45 MeV.
- Retric 11y ago
  Yea, I was off by a factor of 10. https://en.wikipedia.org/wiki/Equivalent_dose https://en.wikipedia.org/wiki/Equivalent_dose 1W of 2.5Mev neutrons ~= 10W worth of Gamma Rays in terms of equivalent dose. (http://ocw.mit.edu/courses/nuclear-engineering/22-01-introduction-to-ionizing-radiation-fall-2006/lecture-notes/absorbed_dose.pdf http://ocw.mit.edu/courses/nuclear-engineering/22-01-introdu...) There are several 14.1+Mev fusion products see chart: https://en.wikipedia.org/wiki/Nuclear_fusion https://en.wikipedia.org/wiki/Nuclear_fusion (Which is probably where I was thinking 100Mev), but it’s already normalized so we are talking 10W equivalent. Granted that 10W dose equivalent is not focused so a person standing next to it might get 8% of that which is .8W, or ~0.01W/kg equivalent (for a 80kg person) which just happens to be ~1 Rads per second. (1 rad = 0.01 Gy = 0.01 J/kg. 250 to 500 rads is the LD/50. So, Standing next to an unshielded 1W neutron source has a 50/50 shot giving you a lethal dose within ~4 to 9 minutes. PS: 2.5Mev Neutron radiation @ 1J per kg is ~10 Gy which is ~LD100 and probably where I was thinking 1W = death. (Please double check my math.)