How does the Tamper in a nuclear bomb survive?

[gvlr96]

I can't really explain my query fully in the space of a title but after hearing an explanation about how nuclear bombs work there is one thing I don't understand - the fissile material is in the centre, around that is the neutron deflector and around that the conventional explosives (this is probably a simplification). The shock waves from the conventional explosives must squeeze the fissile material to critical mass to trigger the chain reaction, but the shock wave must travel through the tamper first. Why is the tamper not destroyed? If the blast is powerful enough to cause critical mass surely any material used for the tamper would not survive?

 

[mathman]

It all gets compressed. The time involved is very short.

 

[mfb]

The tamper gets destroyed mechanically - it doesn't matter, as long as it moves inwards it serves its purpose.

 

[gvlr96]

The tamper gets destroyed mechanically - it doesn't matter, as long as it moves inwards it serves its purpose.

So it gets destroyed but still can do its job - thank you.

 

[mheslep]

So it gets destroyed but still can do its job - thank you.

The momentum of the tamper does the job. A structure can be destroyed; momentum can not be.