Towards Next Generation Radio Imaging Spectroscopy: a Path Forward to FASR

A long term goal of the solar physics community, one that has been endorsed by several NRC decadal surveys, is the Frequency Agile Solar Radiotelescope (FASR). FASR is designed to address a broad program of fundamental solar physics, including coronal magnetic fields, magnetic energy release, particle acceleration and transport, coronal and chromospheric heating, and drivers of space weather such as coronal mass ejections. Fundamental to the FASR concept is observing the chromosphere and corona as a system using innovative measurements — ultra-broadband imaging spectropolarimetry — that will yield unique science data products that are complementary to those produced in, e.g., the O/IR and EUV/X-ray wavelength regimes. The potential of the instrument is already being demonstrated by pathfinder observations made by the Expanded Owens Valley Solar Array (EOVSA) and by the Jansky Very Large Array (JVLA). This talk discusses a step-by-step Implementation of FASR to spread out the cost (the full FASR concept would be in excess of $75M) and achieve some of the most compelling science in time for the upcoming solar maximum. This "stepping stone" approach would first build out the high frequency subsystem at Owens Valley (~1-20 GHz) and rely on other initiatives such as the OVRO Long Wavelength Array to cover the metric wavelength range, deferring the mid-frequency subsystem (~0.2-2 GHz) for the following decade. Such an approach allows a timely deployment of critical science infrastructure that can meet the demands of the wider community while training students and researchers to exploit this new asset. The talk will emphasize the great gain in image quality and science capability of the larger array relative to EOVSA and JVLA.