Gary C
Senior Member.
The authors frequently use the word "atomic" in the paper, even when clearly referring to what would normally be described as "nuclear" or "thermonuclear" items/ topics. It is as if they're unfamiliar with the subject matter. Only fission weapons are normally described as "atomic bombs", and that use is sometimes questioned:
From memory, lay people, at least in the US, routinely referred to nuclear weapons as A-Bombs or H-Bombs or generally as "the atomic bomb" from the 1940s to as late as the `60s and `70s . "Atomic power plants" was also fairly normal and creation of the Atomic Energy Commission reflected that usage. The references survive in fiction of the period including Frank Herbert's Dune, in which characters refer to the nuclear stockpiles of the nobility as 'the family atomics.'
Nuclear became more generally used during the debate of the Nuclear Test Ban Treaty(s) which was covered publicly and at length. The AEC's roles were split up in 1974 with the Nuclear Regulatory Commission assuming oversight of the US civilian nuclear industry. Daily reporting on nuclear weapons reduction treaty negotiations between the US and Soviet Union further standardized the usage of nuclear for younger generations. Strategic Arms Limitation Talks began in 1969.
The authors would have encountered the use of 'atomic' in researching 1950s era UFO sighting reports but should have at least noted the changes in terminology over time to provide clarity for modern readers. This suggests they stuck with the dated use of 'atomic' for esthetic reasons not explained in their work.