Didn’t the Russians test at least one 200+ megaton bomb?
The 50 MT bomb was a “detuned” version of a 100 MT. Although you could make a 200 MT bomb, it would be useless in any real sense.
October 1961, Tsar Bomba, 50 MT.
#2, Castle Bravo, 15 MT, US, lithium-deuteride fuelled and on the Bikini Atoll.
The Soviets had plans for a 100 MT weapon, but near as I can tell never tested it.
Have fun.
The Tsar Bomb was designed for a yeild of 100MT. They reduced it before the test to 50MT.
"The initial three stage design was capable of approximately 100 Mt (Megatons), but at a cost of too much radioactive fallout.
To limit fallout, the third stage, and possibly the second stage, had a lead tamper instead of a uranium-238 fusion tamper (which greatly amplifies the reaction by fissioning uranium atoms with fast neutrons from the fusion reaction).
This eliminated fast fission by the fusion-stage neutrons, so that approximately 97% of the total energy resulted from fusion alone (as such, it was one of the "cleanest" nuclear bombs ever created, generating a very low amount of fallout relative to its yield).
There was a strong incentive for this modification since most of the fallout from a test of the bomb would fall on populated Soviet territory."
The big Russian test was over 50 megatons. The atmospheric shockwave from that test was recorded in NYC. Also the shockwave after going around the planet again. Also the shockwave after going around the planet yet again. And once more.