This project proposes to reuse the DAΦNE accelerator complex for producing a high intensity (up to 1010), high-quality beam of high-energy (up to 500 MeV) positrons for HEP experiments, mainly – but not only – motivated by light dark particles searches. Such a facility would provide a unique source of ultra-relativistic, narrow-band and low-emittance positrons, with a high duty factor, without employing a cold technology, that would be an ideal facility for exploring the existence of light dark matter particles, produced in positronon-target annihilations into a photon+missing mass, and using the bump-hunt technique. The PADME experiment, that will use the extracted beam from the DAΦNE BTF, is indeed limited by the low duty-factor (10-5 =200 ns/20 ms). The idea is to use a variant of the third of integer resonant extraction, with the aim of getting a <10-6 m⋅rad emittance and, at the same time, tailoring the scheme to the peculiar optics of the DAΦNE machine. In alternative, the possibility of kicking the positrons by means of channelling effects in crystals can be evaluated. This would not only increase the extraction efficiency but also improve the beam quality, thanks to the high collimation of channelled particles. This is challenging for < GeV leptons, and in particular this would be the first positron beam obtained with crystal-assisted extraction (generally limited to protons and ions). The availability of an intense extracted positron beam with a tuneable pulse length will also enable other applications, ranging from radiation production from crystal undulators to irradiation for aerospace industry. The second ring can be used for storing positrons accelerated by the LINAC, both for producing synchrotron radiation (reversing the polarity of the ring currently used for electrons) and for machine studies with positively charged particles, like for instance instabilities driven by the electron cloud effect
