RUSSIAN A-TESTS

Press, Volume C, Issue 29634, 3 October 1961, Page 20

RUSSIAN A-TESTS

Analysis By U.S.

. IN .ZJ>. A.-Reuter— Copvrtont) WASHINCTON. Oct. 1. United States scientists who have completed preliminary analysis of about half the 15 Soviet nuclear explosions detected have found no indication of a major Soviet scientific advance. This was indicated in informed United States Government kources yesterday, the Associated Press said. So far, the studies suggest that Soviet weapon experts might be trying out such things as an improved trigger for multi. - megaton bombs, and atomic warheads for anti - aircraft weapons, anti-missile missiles, and tactical size battlefield weapons. However, not all of the detected explosions have been analysed.

The system for detecting nuclear explosions had improved since the United States and the Soviet Unidh proclaimed moratoriums on nuclear tests in late 1938. The details were closelv guarded secrets, A.P. said. Some of the improvements resulted from new equipment, others from refinement of old devices. Various detection methods were used, some useful for only certain types of tests, some used in combination.

The occurrence of a nuclear blast might, in many cases, become known almost instantly, but estimating the precise force and composition of the explosion often required time.

Explosions within th* atmosphere and well above the surface apparently could be detected quickly, „ even though no shock wave might be transmitted through the earth, to be recorded as were earthquakes, the news agency said.

There were several possible methods. One was electromagnetic detection the registering of radio frequency waves generated at the point of nuclear explosion and which radiated to a considerable distance. There also had been suggestions that super-sensitive barographs <the instrument used to register atmospheric pressure) might be used to detect sudden variations in pressure. „ I^ eae microbarographs, sited near Communist territory, might sense th* feint but detectable variations in air pressure as th* blast’s sound wave ratgated outward.