Photos
The wire electrode system is one of the central components of the KATRIN main spectrometer. For many years the high-precision electrode modules have been designed and manufactured under clean room conditions. The last of the 248 modules has been installed in the main spectrometer in January 2012.
The inner surface of the main spectrometer amounts to roughly 650m². Covering this surface the wire electrode reduces the background rate in the spectrometer.
The wire electrode consists of 248 wire electrode modules. Most of them feature two layers of wires with a diameter of 0.2mm or 0.3mm.
Overall more than 23000 wires have been installed and checked. A system consisting of thousands of ceramics and electric connectors makes sure the electrode can stand the out baking at 350°C.
The electrode modules are aligned with a precision of tenth of a mm.
Each module is thoroughly controlled after installation.
The so called intervention system, a nearly 9m tall scaffolding, is used to install the modules.
This pictures gives an idea of the dimensions of the main spectrometer. It is over 24m long and has a diameter of 9m.
The installation takes place under clean room conditions, to make sure the vacuum conditions are not affected.
The electrode system also covers the pumping ports. Pumps will produce a ultra high vacuum with a pressure of 0.00000000000001 bar.
The view into the spectrometer from the central of the three pumping ports.
At this vacant position the last of the 248 wire electrode modules had to be installed.
The electrode installation team during the installation of the last module.
Finished! The last module has been installed in January 2012.
Download of pictures in full resolution (ZIP file, 72MB).
Images: Michael Zacher m.zacher@uni-muenster.de
More information on the KATRIN experiment can be found here:
(http://www.uni-muenster.de/Physik.KP/AGWeinheimer/en/forschung/index.html).