Applying the more detailed form of those calculations to the Ivy Mike device yields vaporized pusher gas expansion velocity of 290 kilometers per second and an implosion velocity of perhaps 400 kilometers per second if 3/4 of the total tamper/pusher mass is ablated off , the most energy efficient proportion . For the W-80 the gas expansion velocity is roughly 410 kilometers per second and the implosion velocity 570 kilometers per second . The pressure due to the ablating material is calculated to be 5.3 billion bar ( 530 T Pa ) in the Ivy Mike device and 64 billion bar ( 6.4 P Pa ) in the W-80 device
Ivy Mike
Ivy Mike
Thermonuclear weapon