Irradiation induced effects in the FE-I4 front-end chip of the ATLAS IBL detector

The ATLAS Insertable B-Layer (IBL) detector was installed into the ATLAS experiment in 2014 and has been in operation since 2015. During the first year of IBL data taking an increase of the low voltage currents associated with the FE-I4 During the first year of the IBL operation in 2015 a significant increase of the LV current of the front-end chip and the detuning of its parameters (threshold and time-over- threshold) have been observed in relation to the received TID. In this talk , the TID effects in the FE-I4 chip are reported based on studies performed in the laboratory using X-ray and proton irradiation sources for various temperature and irradiation intensity conditions. Based on these results, an operation guideline of the IBL detector is presented.