Order number 940406-165953-13 -001-001 page 11 set 5 with 341 of 341 items reflection phenomena. Following shot Teak, echoes were obtained from the rising fission products suggesting that fission fragments may be tracked long after the shot using radars in the hf and vif band. Echoes on 1l, 32, 140, and 370 Mc were obtained from the shot-produced aurora, lasting about one hour after shot Teak and about one-half hour following shot Orange on 140 Mc. The echoes following shot Teak were stronger than those following shot Orange. Within several orders of magnitude, shot-produced auroral echoes appear to be comparable in intensity to a moderate aurora in the arctic. Ionospheric absorption measurements were obtained on 30, 60, and 120 Mc at Johnston Island, French Frigate Shoals (825 km from the burst) and at Wheeler Air Force Base, Oahu (1325 km from the burst), using an instrument which measures integrated absorption over wide angles in the zenith. Absorption was observed at all sites, in some cases lasting several hours. Agreement with theory was adequate. Several secondary experiments were conducted. For example, by monitoring the telemetry from 1958 Epsilon (Explorer IV), shot-produced effects were observable at Johnston Island, 801. KEYWORD(S) Singapore, and Lima for several days after shot Teak. TEAK BURST; ORANGE BURST;RADAR INTERFERENCE; REFLECTION; RADAR SIGNALS;RADAR REFLECTIONS; AURORAE; IONOSPHERIC EFFECTS;ABSORPTION; TIME DEPENDENCE Item 19 150. 110. REPORT NUMBER PRIMARY TITLE (M) RM--3750-PR Geomagnetic disturbances produced by high-altitude nuclear bursts PERSONAL AUTHOR/AFFIL Field, E.C. CORPORATE SOURCE Rand Corp., PUB. DATE (YYMMDD) 630700 CLASSIF. LEVEL TEXT secret 72. 710. 371. 34. 950. ABSTRACT Santa Monica, CA (United States) The possibility that neutron-decay beta particles can cause geomagnetic fluctuations in regions remote from high-altitude nuclear bursts is examined. Particular attention is paid to certain rapid-onset, small amplitude, geomagnetic micropulsations which were detected at great distances from the Orange detonation, August 12, 1958. It appears that micropulsations observed in Southern California and the Arctic after Orange were due to this mechanism. The size and time behavior of these signals are shown to be compatible with theoretical estimates based on the neutron-decay model, and correlation with a nearby VLF anomaly is demonstrated. The analysis indicates that winds at an altitude of about 75 km were dominant in causing the 9003208