Successful test of retro-reflectors on rotating ESS target

The retroreflectors developed at ZEA-1. A small component with a big effect. Copyright: FZJ

Retroreflectors are mirrors that reflect incident light in parallel, regardless of position, movement, offset or rotation. At the ESS, these special radiation-resistant retroreflectors developed at ZEA-1 are used in the moderator & reflector system, the rotating target, the proton beam window and partly in the shielding.

The concept is based on the so-called retroreflection, i.e. the fact that the small surface with retroreflectors reflects the light coming from the optical system, almost independently of the orientation of the surface. The result is that the surface is imaged when it is in the object plane of the imaging system.

They serve as reference surfaces to precisely align the components relative to the proton beam. Furthermore, as can be seen in the following video, also to capture the dynamic position of the rotating target.

ZEA-1 reflectors as fiducials on the rotating ESS target
Cyrille Thomas, ESS
Last Modified: 23.03.2023