Radiation studies on several resistive bulk-Micromegas chambers produced at CERN will be viewed in this document. Two resistive bulk-Micromegas chambers have been installed at the CERN Gamma Irradiation Facility (GIF++) exposed to an intense gamma irradiation with the aim of evaluating the detector behaviour under high irradiation and carrying out a long-term ageing study.
The chambers under study have an active area of 10 x 10 cm$^2$, a strip pitch of 400 $\mu m$, an amplification gap of 128 $\mu m$, and a drift gap of 5 mm.
The results on the detector performance as a function of the photon flux up to 44 MHz/cm$^2$ will be shown as well as the ageing properties as function of the integrated charge and the current intensity and its stability with time. In addition, the results of the efficiency measurements before, during, and after the irradiation will also be presented as a function of the amplification voltage at which the chambers are operated.