Title: POSEYDON - Converting the DAFNE Collider into a double Positron Facility: a High Duty-Cycle pulse stretcher and a storage ring,
Abstract: This project proposes to reuse the DAFNE accelerator complex for producing a
high intensity (up to 10^10), 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
positron-on-target annihilations into a photon+missing mass, and using the
bump-hunt technique. The PADME experiment, that will use the extracted beam
from the DAFNE 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 DAFNE 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.