148. Report of Foreign Weapons Evaluation Group Meeting, October 41
REPORT OF THE FOREIGN WEAPONS EVALUATION GROUP MEETING OF 2–3 OCTOBER 1962
1. Up to date, the Soviets have detonated about 30 nuclear devices in the current series. Almost half of these are thermonuclear devices which range from sub-megaton to 30 megatons in yield. Of these thermonuclear tests, approximately one half are in the 3–6 MT range in contrast with the Soviet 1961 series when half of the thermonuclear tests were in the 1½–3 MT range. The cumulative yield of the Soviet 1962 tests amounts to 130 MT which compares to [text not declassified] the US DOMINIC series. The rate at which Soviet tests have been conducted is comparable to the high rate in the Soviet 1961 series. Debris has been collected and at least partially analyzed on approximately two-thirds of the 1962 tests permitting a preliminary assessment of the Soviet series.
2. For the first time, electromagnetic pulses were observed at relatively close distances from the test site (600–1200 km). The internal evidence from these observations, and especially comparison with calibration observations at 600 to 900 km give interpretable data [text not declassified] (observations at 1200 km and more are difficult to interpret). These observations give a very important new tool for the establishment of the design of the Russian devices. We are [Facsimile Page 2] only at the beginning of exploiting this new tool in our interpretation.
The interpretation depends also on the height of burst. Tests at an altitude of 10,000 ft and higher give clear records, tests at altitudes much below 10,000 usually contain spurious signals arising from the reflection of the KM signal from the ground.
[text not declassified]
[Facsimile Page 3][text not declassified] The fact that a relatively simple and straightforward interpretation of this device appears to explain the observed data does not preclude the possibility that the device was indeed much more complex.
[Facsimile Page 4] [Typeset Page 390]4. [text not declassified]
It appears from preliminary analysis that these may represent older, i.e., pre-1961 Soviet designs.
6. Two of the thermonuclear tests were sub-megaton, namely 400 KT and 160 KT in yield. [text not declassified]
[Facsimile Page 5]7. The analysis of the Soviet 1961 fission devices was not completed until after the last meeting of this panel, it is therefore appropriate to include a summary of them in this report. In the Soviet 1961 series there were 16 tests of fission devices for which debris was collected and analyzed. [text not declassified] Of the unboosted fission devices tested in 1961, the majority bear strong resemblance to devices previously tested in 1957 and 1958. One test was of an oralloy device which may have been either a gun assembly or a large spherical implosion device.
[Facsimile Page 6]8. Of the approximately 15 fission devices tested by the Soviets in the 1962 series, debris has been collected and analyzed on approximately 10. Only two of those show presence of a boost and all have tuballoy tampers. This appears to be a marked distinction to the 1961 series in which considerable effort was given to boosting and to the elimination of the tuballoy tampers.
- Discussion of current series of Soviet detonations. Top Secret. 5 pp. Kennedy Library, National Security Files, Bromley Smith Safe, Drawer 1, Bethe Report, 10/4/62.↩