Limits on thermally-distributed halo dark-matter axions from ADMX

The Axion Dark Matter eXperiment (ADMX) at Lawrence Livermore National Laboratory searches for dark-matter axions through their Primakoff conversion to microwave photons in a strong magnetic field, resonantly enhanced by a high-Q cavity. The ADMX medium resolution analysis assumes that halo axions are thermalized with the local virial velocity of the Milky Way, about $270 \frac{km}{sec}$, which implies a spectral line-broadening of one part per million. ADMX has set limits on halo axions for the KSVZ model from $1.6 eV$ to $3.6 eV$. The experiment is the most sensitive spectral receiver in the world, able to detect signals from $400MHz$ to $900MHz$ well below a yoctowatt. This talk will outline the experimental technique, data analysis and results for the medium-resolution search.