Speaker
Description
The FINESSE beamline is a proposed particle-physics instrument at the European Spallation Source (ESS) in Lund. It is designed to utilise the high cold-neutron brightness, pulsed time structure and long flight path available at ESS to address open questions in particle physics, including baryon number violation, new sources of CP violation and the nature of dark matter.
The primary strength of FINESSE is its ability to accommodate two complementary classes of particle-physics experiments within a single facility. In its high-flux configuration, an intense neutron beam is transported through a long, magnetically controlled region for neutron oscillation searches. A dedicated annihilation detector, combining charged-particle tracking, calorimetry and cosmic-ray rejection, is designed to identify the multipion signature produced if an antineutron annihilates in a target foil. Detector prototypes, readout systems and reconstruction methods are actively being developed within the collaboration. By exchanging a short section of neutron guide inside the ESS bunker, FINESSE can also operate in a low-background configuration ideal for precision measurements of neutron decay, hadronic parity violation and the neutron electric dipole moment.
The beamline would establish a major new programme at the interface of Swedish particle, nuclear and neutron physics. In this presentation, I will describe its scientific use cases and the current status of the beamline and detector development.