Testing integrated COTS DC/DC converters in hostile environment

We have irradiated three integrated COTS DC/DC converters with a 60Co gamma-source at different dose rates, 5, 10 and 22 Gy/h, up to about 4 kGy. During the tests they were biased and loaded, and remotely monitored. After the irradiation, we performed a room-temperature annealing for two weeks, followed by another short-period irradiation. Two of such converters were also tested in a static B field up to 1 T. We have also built a DC/DC converter with GaN devices in the final stage, testing it under gamma-rays together with all other converters, and in a static B field. Results shown here, combined with the ones obtained by the Michigan team led by Dante Amidei, with which we are collaborating, demonstrate that most of the tested DC/DC converters could work in a highly hostile environment, like the one in which the ATLAS New Small Wheel (NSW) detector will operate after the phase 1 upgrade. COTS and custom DC/DC converters are now under test in a fast neutron facility. Irradiation with protons and heavy ions will follow in the next months.