  We present a proposal for a new experiment, the FINUDA magnet for Light Axion
SearcH (FLASH), a large resonant-cavity haloscope in a high static magnetic
field which is planned to probe new physics in the form of dark matter (DM)
axions, scalar fields, chameleons, hidden photons, as well as high frequency
gravitational waves (GWs). Concerning the QCD axion, FLASH will search for
these particles as the DM in the mass range (0.49-1.49) ueV, thus filling the
mass gap between the ranges covered by other planned searches. A dedicated
Microstrip SQUID operating at ultra-cryogenic temperatures will amplify the
signal. The frequency range accessible overlaps with the Very High Frequency
(VHF) range of the radio wave spectrum and allows for a search in GWs in the
frequency range (100-300) MHz. The experiment will make use of the cryogenic
plant and magnet of the FINUDA experiment at INFN Frascati National
Laboratories near Rome (Italy); the operations needed to restore the
functionalities of the apparatus are currently underway. We present the setup
of the experiment and the sensitivity forecasts for the detection of axions,
scalar fields, chameleons, hidden photons, and GWs.
