Event Details

Speaker: Paolo Beltrame

Abstract:

The axion is a compelling dark matter candidate — a pseudoscalar particle originally proposed to solve the strong CP problem — with a predicted mass spanning a wide range, from peV to a few meV. Axions gravitationally bound within our galaxy could be detected using haloscopes: resonant cavities placed in a static magnetic field, where axion-to-photon conversion produces a detectable microwave signal. Haloscopes are also being explored as tools to search for high-frequency gravitational waves.

Following a brief overview of the underlying physics, this talk presents the status and prospects of dark matter and gravitational wave searches at INFN (https://www.sciencedirect.com/science/article/pii/S2212686423002042), with a particular focus on contributions from the University of Liverpool. At the heart of this programme is FLASH — a large-scale haloscope under construction, built around a repurposed superconducting solenoid of 1.4 m radius, 2.2 m length, and 1.1 T field strength. FLASH will probe axions in the ~1 μeV mass range, with sensitivity extending to dark photons and high-frequency gravitational waves. Signal readout will employ quantum sensing technologies — including SQUIDs and quantum amplifiers — to approach the quantum noise limit and maximise experimental sensitivity. Following a recent refurbishment of its cryogenic lines and control system, the magnet was successfully energised at approximately 2700 A, restoring a 1.1 T field for the first time in nearly two decades.

The talk will also highlight complementary projects currently under study and development in Liverpool, within the framework of the Northwest Quantum Network.