Editing Soviet atomic bomb project (section)

=== RDS-6s ===
[[RDS-6|RDS-6s]], the first Soviet test of a [[hydrogen bomb]], took place on August 12, 1953, and was nicknamed ''Joe 4'' by the Americans. It used a layer-cake design of fission and fusion fuels (uranium-235, lithium-6 deuteride, and lithium-6 deuteride tritide) and produced a yield of 400 kilotons. This yield was about ten times more powerful than any previous Soviet test.<ref name=":0" /> When developing higher level bombs, the Soviets proceeded with the RDS-6 concept as their main effort instead of the analog RDS-7 advanced fission bomb. This led to the third idea bomb which is the [[RDS-37]].<ref name=":0" />