The Co-60 irradiation facility at Ruđer Bošković Institute in Zagreb allows for gamma irradiation in a large range of doses from a maximum of 30kGy/h down to 30Gy/h. Recently, a setup for the radiation tolerance study of readout electronics has been built inside the irradiation chamber. This setup allows for performing tests in conditions similar to ones that will be experienced at HL-LHC experiments. The irradiation dose rate is close to the dose rate at 3cm from the p-p interaction point, the temperature inside cold boxes is controlled by using chilled water and Peltier elements, and the relative humidity is defined by dry air flushed through the cold boxes.

The setup is used for irradiation of ATLAS and CMS pixel detector prototype readout chips, called RD53A. This chip is built in 65 nm CMOS technology that demonstrates a radiation damage dependence on the irradiation dose rate. In this paper the setup itself and a few preliminary results of the radiation damage received at the low dose rate will be presented.