Atmospheric Nuclear Detonation - Joe 4, the Sloika

Name:Joe 4, the Sloika;
Date:August 12, 1953;
Site:Semipalatinsk, Kazakhstan;
Detonation:Tower; Yield:400kt;
Type:Fission/Fusion, U²³⁵/Li⁶/Tritium;

   Although it was Soviet's fifth nuclear detonation, for some reasonon the west it was dubbed as Joe 4. I doubt US intelligence would miss an atomic explosion in USSR, so I guess it was something else. Anyway, the device codenamed RDS-6 was built upon Sakharov's Sloika design. It was not a true H-Bomb, as most of its yield came from fission. Nevertheless, it demonstrated fusion reaction in a deliverable weapon sized device. Obviously that bolstered up US determination to create a deliverable thermonuclear weapon and took nuclear arms race one step further.
    RDS-6 employed both, fision and fusion rections. Fissile material - U²³⁵, which was layered with fusion fuel - Li⁶, and that in turn was mixed with Tritium. The practical yield limit for this type of device was below 1mgt. It was not widely deployed, as more successfull Teller-Ulam design appeared soon.