Joshua Spitz’s research explores a new method of measuring the cosmic ray rate imprinted on rocks over the past billion years. Making this measurement has the potential to increase the sensitivity to historic cosmic ray rates on the earth by two orders of magnitude and to enable us to examine the rate evolution across up to 5 galactic orbits of the earth.
His team searches for rare-event-induced signature damage (from atmospheric neutrinos) to the crystalline structure of natural minerals excavated from deep underground. The advantage of his technique is that the minerals in question have been collecting data deep beneath the Earth’s surface for 100s of million or even billions of years. His team aims to establish the detailed imaging and pattern recognition strategy for characterizing micrometer-scale rare events in these minerals using X-ray and electron microscopy techniques.
Understanding the cosmic ray rate evolution complements techniques used by multiple scientific disciplines to probe the history of the Earth including ones used in astrophysics, geology, atmospheric science, and biology. Dr. Spitz’s research represents a “jumping-off” point for considering other ancient-mineral-based searches that might include dark matter, supernova neutrino interactions, and other exotic astrophysical phenomena.
Experimental Physics Investigators Initiative
University of Michigan, Department of Physics