The International Axion Observatory: towards a new generation axion helioscope

by Dr Igor Irastorza (Zaragoza University)

Tuesday 25 Mar 2014, 17:00 → 18:30 Europe/Berlin

Auditorium (MPI fuer Physik)

The International Axion Observatory (IAXO) will be a fourth generation axion helioscope. As its primary physics goal, IAXO will look for axions or axion-like particles (ALPs) originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal to background ratio, IAXO will be about 4-5 orders of magnitude more sensitive than CAST, the most sensitive axion helioscope to-date. IAXO has the potential for the discovery of axions and other ALPs, since it will deeply enter into unexplored parameter space. In particular it will probe a large fraction of the high mass part (1 meV to 1 eV) of the QCD axion allowed window. IAXO could also detect solar axions produced by mechanisms mediated by the axion-electron coupling $g_{ae}$ with sensitivity $-$for the first time$-$ to values of $g_{ae}$ not previously excluded by astrophysics. IAXO follows the layout of an enhanced axion helioscope, with a purpose-built 20-m-long 8-coils toroidal superconducting magnet. All the eight 60-cm diameter magnet bores are equipped with focusing x-ray optics, able to focus the signal photons into $\sim 0.2$~cm$^2$ spots that are imaged by ultra-low-background Micromegas x-ray detectors. The magnet is built into a structure with elevation and azimuth drives the will allow for solar tracking for $\sim$12 h each day. All the enabling technologies exists, there is no need for development. Potential additional physics cases for IAXO are the search of axionic dark radiation, the realization of microwave light-shining-through wall setups or the search of more specific models of weakly interacting sub-eV particles (WISPs) at the low energy frontier of particle physics. But most interestingly, IAXO may also host relic axion detectors based on resonant cavities or dish antennas, following recently proposed ideas. IAXO has the potential to serve as a multi-purpose facility for generic axion and ALP research in the next decade.