How deep/wide is the crater from an H-bomb?
And what is a nutron bomb.
About a mile across, if you detonate it close enough to the ground to make a crater. An air burst would leave a proportionately smaller crater, with a larger irradiated area. Neutron bombs are ones which have a much higher radiation-to-explosion ratio so it’s possible to kill everybody in town without blowing the town up as much.
The biggest above-ground H-bomb test that the U.S. ever performed, “Castle Bravo”, had a strength of approximately 20 megatons. It left a crater (a new lagoon, actually) on the test island about 1.2 miles across. After we switched to underground testing, the bombs got a lot bigger (we’re certainly capable of building over-100 megaton bombs nowadays), but that’s probably not the kind of crater you’re talking about. For good info and lots of test footage, rent Trinity And Beyond: The Atomic Bomb Movie.
Someone else can do neutron bombs, I don’t know much about 'em myself.
Neutron bombs were designed during the Cold War era. At that time, the Soviets had a lots more tanks than NATO did. If the Soviets decided to launch a massive tank led attack on Europe, NATO could not stop them.
Neutrom bombs were developed to stop the advance of the tanks. No one planned to use them to nuke cities. If the tanks want to stay in a city, the tanks would be safe. Of course, to capture territory, the tanks have to leave the cities.
Tanks are very tough. It would take a huge explosion for the shock wave [concusion] to be big enough to wipe out a lot of tanks; especially when the tanks are spread out. Europe is fairly densely populated. A huge nuclear blast would destroy lots of nearly towns.
Instead of using a blast to destroy the tanks, the neutron bomb puts out a lot of radiation that can penetrate the steel on the tank and kill the tanks’ crews. Note that this is increased radiation, not increased radioactive fallout. You still get some radioactive contamination, but not much more than “normal”. The blast is small enough that nearby towns are not destroyed.
The Soviets had no defense against the neutron bomb. They countered with propaganda. You will hear that the neutron bomb is for use against cities; to kill the people but safe the buildings. Why would NATO bomb one of their own cities? Killing your own people is not a good way to win a war.
Whoops, my mistake, Castle Bravo was “only” 15 megatons, not 20. The fireball was around 4 miles across, though the crater was a mere 6000-6500 feet across.
I’d also like to say that the footage of the Castle Bravo test (which you can view in the previously mentioned movie) is one of the scariest things I’ve ever seen on film. That bomb literally melted the sky.