I think I've read about using a swarm of these probes "at the focal region of the solar gravitational lens" (i.e. in spherical shell starting 548 AU from the

I think I've read about using a swarm of these probes "at the focal region of the solar gravitational lens" (i.e. in spherical shell starting 548 AU from the Sun) in A Sci-Fi novel. I think this one: https://www.goodreads.com/book/show/13039884-existence https://www.goodreads.com/book/show/13039884-existence