ADMX-Extended Frequency Range: 2-4 GHz Search

The Axion Dark Matter eXperiment (ADMX) is a microwave cavity search for axions in the galactic halo. At present, ADMX has scanned the 600 MHz to 1 GHz frequency range. There are plans to extend the search and scan higher frequency regions. One design in particular consists of an array of cavities that will be tuned over the 2-4 GHz frequency range. The current baseline design is to use 18 identical cavities in a 9.4 T 800 mm diameter magnet. In this talk, we will discuss the concept, design, and preliminary results from experiments on prototype cavities to be used in this search.

This work was supported by the U.S. Department of Energy through Grants No DE-SC0009800, No. DE-SC0009723, No. DE-SC0010296, No. DE-SC0010280, No. DE-SC0011665, No. DEFG02-97ER41029, No. DE-FG02-96ER40956, No. DEAC52-07NA27344, No. DE-C03-76SF00098 and No. DE-SC0017987. Fermilab is a U.S. Department of Energy, Office of Science, HEP User Facility. Fermilab is managed by Fermi Research Alliance, LLC (FRA), acting under Contract No. DE-AC02-07CH11359. Additional support was provided by the Heising-Simons Foundation and by the Lawrence Livermore National Laboratory and Pacific Northwest National Laboratory LDRD office