Exploring 0.1-10$\,$eV axions with a new helioscope concept

TL;DR

This paper proposes a novel axion helioscope using a large volume TPC in a magnetic field, capable of detecting higher mass axions without tracking the Sun, and demonstrates its potential sensitivity to probe certain axion models.

Contribution

It introduces a new helioscope concept utilizing a TPC with variable gas mixtures and pressures, enabling detection of axions in the 0.1 eV to several eV mass range, which is a significant advancement over traditional methods.

Findings

Potential sensitivity of a few × 10^{-11} GeV^{-1} for axion-photon coupling.

Can probe the KSVZ axion model for masses above 100 meV.

Flexible operation with different gases and pressures enhances detection capabilities.

Abstract

We explore the possibility to develop a new axion helioscope type, sensitive to the higher axion mass region favored by axion models. We propose to use a low background large volume TPC immersed in an intense magnetic field. Contrary to traditional tracking helioscopes, this detection technique takes advantage of the capability to directly detect the photons converted on the buffer gas which defines the axion mass sensitivity region, and does not require pointing the magnet to the Sun. The operation flexibility of a TPC to be used with different gas mixtures (He, Ne, Xe, etc) and pressures (from 10 mbar to 10 bar) will allow to enhance sensitivity for axion masses from few meV to several eV. We present different helioscope data taking scenarios, considering detection efficiency and axion absorption probability, and show the sensitivities reachable with this technique to be few $\times$ 10$^{-11}\,$GeV$^{-1}$ for a 5$\,$T$\,$m$^3$ scale TPC. We show that a few years program taking data with such setup would allow to probe the KSVZ axion model for axion masses above 100 meV.