As hypothesized by Unruh, an accelerating  observer will observe black-body radiation with temperature T=a \hbar/(2 \pi c k_B). The Josephson junction radiates with very low power. Does this radiation follow the Unruh radiation?

When a Cooper pair is accelerated through the junction with width L by a voltage V, its acceleration is a=qV/mL and its temperature of the order of some few K, that is  a typical temperature of the Junction. This can be expressed as T=(hbar/2 pi m c) qV/k_B .