Rats spent more time in the halves of shuttle boxes that were shielded from
illumination by 12 GHz microwave energy than in the unshielded. In Experiment 1, rats aYoided the energy when it was presented as 30-µsec pulses
with a pulse repetition rate of 100 pulses per second (pps). The average
power density was about .6 m ‘\V /cm”, and the peak power density was
about 200 m “\V /cm’. In Experiment 2, the energy was presented both continuously and in pulse-modulated form, i.e., .5-msec exponentially decaying pulses at a rate of 1,000 pps. The average power density of the con–
tinuous energy was 2.4 m,1V /cm 2, and the average power density of the·
pulse-modulated energy was 2 m vV /cm2
• The peak power density of the
modulated energy was 2.1 mW