Exploring backgrounds of low-mass axion searches with ABRACADABRA-10cm

Originally proposed as a solution to the strong CP problem, the axion is also well motivated as a candidate for dark matter. In the less-explored axion mass range below a ueV, axions behave as long-wavelength dark matter, the search for which requires novel approaches and techniques. With ABRACADABRA-10cm we demonstrated the ability to search for GUT-scale axions in the range of 0.3 to 8 neV, reaching below the CAST limit, using a superconducting toroidal magnet, quantum electronics, and a broadband, lumped-element circuit. While ABRACADABRA-10cm does not reach the QCD axion limits, future upgrades aim to hit this limit. We have characterized sources of noise in ABRACADABRA-10cm that will allow for better informed upgrades and designs for the DMRadio program. In this talk, I will discuss ABRACADABRRA-10cm and the noise sources associated with a broadband lumped-element search.