Probing the structure of the cold dark matter halo using ancient mica

Mica can store (for {gt}1thinspGyr) etchable tracks caused by atoms recoiling from WIMPs. Ancient mica is a directional detector despite the complex motions it makes with respect to the WIMP {open_quotes}wind.{close_quotes} We can exploit the properties of directionality and long integration time to probe for structure in the dark matter halo of our galaxy. We compute a sample of possible signals in mica for a plausible model of halo structure. {copyright} {ital 1998} {ital The American Physical Society}