The COHERENT collaboration made the first measurement of coherent elastic neutrino nucleus scattering (CEvNS) in 2017 using a low-background, 14.6-kg CsI[Na] detector at the SNS. Since initial detection, this detector has opened a new era of precision CEvNS measurements by doubling the detector exposure and improving understanding of the detector response. We these improvements, we now use CsI[Na] data to make competitive constraints of beyond-the-standard-model physics. 

The CEvNS process is highly sensitive to extensions beyond the standard model, and, as the cross section is precisely predicted by the standard model, it is ideal for these searches. We will outline the breadth of the new physics accessible to CEvNS detectors at the SNS with a focus on detection of accelerator-produced dark matter. With our experience measuring CEvNS, we are sensitive to analogous coherent dark matter induced recoils in our detector. This is a novel approach for accelerator-based dark matter experiments. Searching in this channel is also very powerful, allowing relatively small detectors to explore new parameter space inaccessible to much larger detectors. We will discuss current data constraints from our CsI[Na] detector which placed the most stringent constraint on dark matter with a mass in the 10s of MeV and future sensitivity of the next generation of COHERENT detectors to discover dark matter.