Crossroads Able, airdrop over Bikini atoll in summer 1946. This was an airburst effects test of a "stockpile" bomb. It was almost certainly a MK-4 (improved composite core implosion device in a much lighter and easier to assemble casing than the MK-3 Fatman).
electrical battery chemistryconventional explosive detonation chemistry
detonation of an atomic bomb? I believe it is gamma radiation.Fallout emits large amounts of gamma.It is neutrons.
from roughly 30,000 feet to detonation at roughly 1500 feet.
In excess of 50,000 meters/second, but the exact velocity depends on yield.
There was no 4th atomic bomb.
The use of the atomic bombs in 1945 did not 'cause the Cold War'.
The first detonation of a nuclear device was the Trinity Detonation on July 16, 1945 35 miles southeast of Socorro, New Mexico
The detonation of the bomb seemed fast approaching and inevitable.
Smoke rockets launched just before the detonation of a test device to help measure the blast wave.
1945
1945
Detonating a fission bomb.