PT Journal AU Ahyoune, Sea Gimeno, B Reina-Valero, J TI A Proposal for a Low-Frequency Axion Search in the 1-2 μeV Range and Below with the BabyIAXO Magnet SO Annalen der Physik JI Ann. Phys. PY 2023 BP 2300326 EP 23pp VL 535 IS 12 DI 10.1002/andp.202300326 LA English DE axions; dark matter; dark photons; haloscopes; IAXO AB In the near future BabyIAXO will be the most powerful axion helioscope, relying on a custom-made magnet of two bores of 70 cm diameter and 10 m long, with a total available magnetic volume of more than 7 m(3). In this document, it proposes and describe the implementation of low-frequency axion haloscope setups suitable for operation inside the BabyIAXO magnet. The RADES proposal has a potential sensitivity to the axion-photon coupling g(alpha gamma) down to values corresponding to the KSVZ model, in the (currently unexplored) mass range between 1 and 2 μeV, after a total effective exposure of 440 days. This mass range is covered by the use of four differently dimensioned 5-meter-long cavities, equipped with a tuning mechanism based on inner turning plates. A setup like the one proposed will also allow an exploration of the same mass range for hidden photons coupled to photons. An additional complementary apparatus is proposed using LC circuits and exploring the low energy range (approximate to 10(-4)-10(-1)mu eV). The setup includes a cryostat and cooling system to cool down the BabyIAXO bore down to about 5 K, as well as an appropriate low-noise signal amplification and detection chain. ER