The Livescience article NASA's Tiny New Atomic Clock Could Let Spacecraft Drive Themselves in Deep Space says:
But the radiation still changes the way the electronics operate. And those changes impact the sensitive equipment atomic clocks use to measure time slipping by, threatening to introduce inaccuracies. Multiple times a day, Seubert pointed out, the Air Force uploads corrections to the GPS satellites' clocks to keep them from drifting out of sync with clocks on the ground.
The goal of the DSAC, she said, is to establish a system that's not only portable and simple enough to be installed on any spacecraft but also hardy enough to operate in space over the long term without requiring constant adjustments from Earth-based teams.
Question: At what altitude was the first Deep Space Atomic Clock placed in Earth orbit? Does it experience a sufficiently high radiation environment there to demonstrate it's ability to withstand radiation in deep space?