PERIODIC SIGNATURES FOR THE DETECTION OF COSMIC AXIONS

In a Sikivie-type cosmic-axion detector, both the width and position of the microwave signal due to axion-photon conversion depend upon the motions of the Earth. Because of the orbital and rotational motions of the Earth they will be modulated with periods of 1 sidereal day and 1 sidereal year, with amplitudes of about 0.1% and 5%, respectively. Because of the intrinsically high-energy resolution of Sikivie-type detectors such periodic variations should be detectable. These modulations would not only aid in confirming the detection of cosmic axions, but, if found, would also provide important information about the distribution of axions in the halo. © 1990 The American Physical Society.