Neutron Guides for Ultracold Neutrons
Replica tube. Pure Nickel. A polished glass plate was coated with a nickel layer, reinforced with a galvanised nickel layer and removed from the glass. Then rolled to a tube and welded.
A two meter long replica tube. The roughness of the nickel layer inside is the same as for polished glass: Around 0.5 nm Ra. The lowest roughness of metal worldwide.
The replica ucn tubes are positioned in a round vacuum housing.
Glass tubes or electroplated steel tubes are coated with NiMo inside.