|MadSci Network: Physics|
I am not sure what you mean by your question. If I assume that your word "collapse" means "compress" I can answer from personal experience. In the summer of 1964 I worked at Los Alamos in a group doing explosive compression of magnetic fields. The idea was to make ultra high magnetic fields. A typical experiment involved a tungsten cylinder about 5 inches in diameter and a foot long. The cylinder was placed in a Helmholtz coil powered by a room size capacitor bank. Around the tungsten cylinder was placed a large doughnut of very high energy explosive which weighed perhaps 100 pounds! It had about 100 detonators arranged on the outside of the doughnut. At the end of the countdown the capacitor bank discharged pushing a very high current into the Helmholtz coil. This made a field of about 20,000 Oe. The rise time of the field was slow enough that it could diffuse through the tungsten cylinder. At the peak field the explosive was detonated which compressed the cylinder so quickly that the field lines could not diffuse out. The hole in the cylinder got smaller until the pressure of the field equaled the pressure from the explosive. The result was a field of over 15,000,000 Oe which was a record that stood for over 20 years! The experimentors (including me) were in a concrete and steel bunker only 25 feet or so from the explosion. It was quite an experience. I have a lot of sympathy for the folks in Iraq who have to worry about similar explosions without the bunker.
Try the links in the MadSci Library for more information on Physics.