The CAST-RADES project progress: electrical tuning ideas and a new 30 sub-cavities axion detector design

Resumen

Progress on the possibilities for implementing frequency tuning and increasing the volume of RADES (*Relic Axion Detector Exploratory Setup*) axion search cavities are described. The cavities works at X-Band and consist of inter-coupled sub-cavities. A first 5 cavity prototype split into two halves has been manufactured and provides a tuning range of 700 MHz by varying the distance of the two halves. Alternatively, tuning with ferroelectric materials varying the dielectric permittivity is being investigated and simulated. In order to increase cavity volume, and thus sensitivity, a new 30 sub-cavities detector design provides a higher volume keeping the previous RADES frequency range, of ~8.4 GHz. The 30 cell cavity considerably increases the sensitivity of the sensor as compared to the previous experiment. A description of the theoretical framework and the simulations of the electromagnetic properties of the system will be presented.