| Joe-4 RDS-6s | |
|---|---|
| Information | |
| Country | Soviet Union |
| Test site | Semipalatinsk Test Site, Kazakh SSR |
| Period | August 1953 |
| Number of tests | 1 |
| Test type | Atmospheric test |
| Device type | Boosted fission |
| Max. yield | Total yield 400 kilotons of TNT (1,700 TJ) |
| Test chronology | |
RDS-6s (Russian: РДС-6с, from the Soviet codename for their atomic bombs Russian: Реактивный Двигатель Специальный, lit. 'special jet engine'; American codename: Joe 4) was the first Soviet attempted test of a thermonuclear weapon that occurred on August 12, 1953, that detonated with a force equivalent to 400 kilotons of TNT.
RDS-6 utilized a scheme in which fission and fusion fuel (lithium-6 deuteride) were "layered", a design known as the Sloika (Russian: Слойка, named after a type of layered puff pastry) or the so-called layer cake design, model in the Soviet Union. A ten-fold increase in explosive power was achieved by a combination of fusion and fission, yet it was still 26 times less powerful than the Ivy Mike device tested by the US in 1952. A similar design was earlier theorized by Edward Teller, but never tested by the US, as the "Alarm Clock".[1]