I think that you need not to move the bomb to stratospere. Smith in Doomsday men gave estimate that doomsday cobalt bomb should weight near the weight of lincor Missuri that is 70 000 tonn. So you could detonate it on spot—and the enegry of explosion will bring isotopes to upper atmosphere.
Also, if we go in technical details about global radiological contamonation, I think it would be better to use not only cobalt but other isotopes. Gold was discussed as another one. But the best could be some kind of heavy gas like radon because it is does not (as I think) solve in the see but tend to stay in lower atmosphere. It is not a fact but just my opinion about making nuclear doomsday divice more efective, and while I think this partilur opinion is wrong, some one who really wants to make such device could find the ways to make it much more effective , taking different isotopes as blanket of the bomb.
Thank you for clarification of your position.
I think that you need not to move the bomb to stratospere. Smith in Doomsday men gave estimate that doomsday cobalt bomb should weight near the weight of lincor Missuri that is 70 000 tonn. So you could detonate it on spot—and the enegry of explosion will bring isotopes to upper atmosphere.
Also, if we go in technical details about global radiological contamonation, I think it would be better to use not only cobalt but other isotopes. Gold was discussed as another one. But the best could be some kind of heavy gas like radon because it is does not (as I think) solve in the see but tend to stay in lower atmosphere. It is not a fact but just my opinion about making nuclear doomsday divice more efective, and while I think this partilur opinion is wrong, some one who really wants to make such device could find the ways to make it much more effective , taking different isotopes as blanket of the bomb.