[Vehicles] How big should a self-destruct be?

[DataPacRat]

Originally Posted by DataPacRat

After some further reading myself, the simple equation for explosive force is 4 kg per gram of TNT; so it looks like I can simply multiply the total radiation by the mass of the isomer.

Temporarily sticking with $1 worth of isomers, 1/500 lb, sticking to inverse square, if we have 3M rads at 10cm, that'd be 30k rads at 1 metre, 300 rads at 10 metres, and 3 rads at 100 metres. Or, if we go up to 1 lb, worth $500, it's 1,500 rads at 100 metres, and 15 rads at 1 km.

... Anyone know offhand how much air absorbs hard x-rays of around 30.77 keV / 7.44 EHz / 40.3 picometres? I know that the overall atmosphere absorbs pretty much all cosmic x-rays before they reach the ground, and I've been able to dig up the occasional reference such as https://www.exul.ru/education/1/30.pdf that seems to imply the process takes on the order of a few 10s of metres of air. (I've also found tables such as https://physics.nist.gov/PhysRefData...omTab/air.html , but I don't yet understand what things like "μ/ρ" or "μen/ρ" mean.) On the other hand, if x-rays of this energy level are reasonably penetrating, then I don't see too many governments allowing the production, storage, or use of such isomers anywhere near a biosphere.

After eyeballing some more charts, I finally got an estimate that about 15 metres of air absorbs half of the X-rays of this wavelength. Based on that, I was able to throw together a quick spreadsheet to estimate concussion damage and whole-body rads received, in vacuum and in air, at https://docs.google.com/spreadsheets...n-8/edit#gid=0 . (The one thing I haven't figured out how to turn into an equation is 3e's rules on explosive damage range, which doubles for every so many dice of damage.)
For 1 lb of isomers and carrier goop, I end up with in-atmosphere numbers of:
0-12 metres: >50,000 rads, death in 0-1 hours
14-30 metres, >3,000 rads, death in 1-2 days
35-40 metres, >1,000 rads, death in 1-2 weeks
45-50 metres, >400 rads, 50% chance of death
55-70 metres, >100 rads, acute radiation sickness
75-135 metres, >1 rad, little immediate effect
150+ metres, <1 rad, no immediate effect.
... all of which compare to average concussion damage, which in 3e terms is around 200 (blown to smithereens) at 9 metres, 10 (50% death for unprotected person) at about 17 metres, and around 0 at 30 metres. In vacuum, there's at least 400 rads out to 150 metres, and 100 rads out to 350 metres.

... All of which adds up to some fairly strong reasons that this stuff isn't used as an everyday explosive, and is likely LC1. And the only reason I'm not dropping it to LC0 is that it's a fairly self-contained zone of death without much risk of spreading uncontrollably, the way fallout or bioweapons (the standard examples for LC0) can. But I might change my mind; maybe I'll peg it around an average of LC0.5, depending on jurisdiction.