Helmholtz Zentrum Berlin


hzbEMIL • Watching the Secret Lives of Atoms

The Mirror Zoo

authored 4 years ago:

Seven years of unlucky love

Yesterday I met with our mirror manufacturer Alexander Pilz who came all the way from Oberkochen to find out what might be salvageable from the broken mirror. It was a short visit. After we cleaned off the dust with acetone, we didn't even bother to continue with any measurements. We had been aware of the deep scratches on the one side, but hoped to be able to use parts of the other side. No such luck. ()

While the scratch on the other side was tiny, it was also quite deep and - worst of all - in the middle of the optical aperture. ()

But even if the surface quality would have been within acceptable margins, Alexander would still have insisted on taking the mirror back. After such a blow – whatever it was that happened to the package during transport – there is no telling what happened to the inner structure of the mirror. It’s a silicon mono-crystal, they are very fragile. And later on, once it’s mounted in the beamline – you don’t even want to imagine what would happen if the mirror shattered there.


So it’s back to square one. Which not only sets us back at least three or four weeks, but this was also one of the finest mirrors ever delivered by Alexander, with super low roughness and high brilliance. Thank you, transport company that shall not be named, and remember: breaking a mirror means seven years of unlucky love!