Minerals as Time-Integrating Luminescence Detectors for setting bounds on dark matter particle characteristics

Terrestrial material, since its formation, is supposed to receive additional radiation dose from its exposure to fluxes of dark matter particles. The present work investigates the possibility for bound estimation of interaction parameters of dark matter particles with ordinary matter, by measuring the accumulated doses of certain geological materials. It is proposed that Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) could enable the differentiation between the individual dose components, attributing a possible excessive dose, beyond the anticipated from cosmic rays and environmental radioactivity, to interactions with dark matter particles. Dosimetric properties of natural calcium fluoride, such as low detectable dose limit and low energy threshold (well below 1 keV), indicate it as a promising Thermoluminescent Dosimeter (TLD) for the proposed method. The limitations imposed by the “background” of cosmic rays and environmental radioactivity are discussed, and initial limits for the interaction strengths with ordinary matter, and/or the mass of WIMPs and axions are derived. The use of sedimentary quartz, sited in a free-from background-radiation environment, would yield a value of 4×10−8 GeV−1 as an upper limit for the axion-to-photon interaction constant gaγγ and a value of 3×10−8 GeV as a lower limit for the neutralino mass. The best limits, gaγγ=1.1×10-10GeV-1 for solar axions and m=3000GeV for neutralinos, could be derived for natural calcium fluoride as a dosimeter.