Preparing the Tubes

A clean but raw tube mounted in the jig ready for us to string the wire through.

The wire is carefully pulled through the tube, threaded through an endplug and then the endplug is mounted with suction to the otherside of the foreground part.

The swager, which uses a sudden and large magnetic field to compress the aluminum tube onto the endplug.

This end is ready to be swaged. The plastic cap is offers some protection if the magnet "explodes." Below it is the mechanism that crimps the wire in place.

The first stage of contruction is cutting and cleaning the tubes. Mike did this work while I was in Paris. So, when I arrived we had a nice pile of nearly 120 clean tubes to work with. Next we need to run a tiny gold coated tungsten wire through the tubes and attach endplugs with a magnetic swaging process. The endplugs keep the wire lined up in the exact center of the tube (very imporant for precision), insulate the wire from the wall (there will be 3000 volt difference), and allow gas to flow through. The wire is given a fixed amount of tension before being crimped in place at both ends. Next we check the endplugs for leaks by filling the tubes with helium and sucking on the ends with a leak detector that uses mass spetroscopy to pick out He molecules. We then take the tubes to another room where we connect them together in groups and flow the working gas through, which is a mixture of 93% Ar and 7% CO2. We pressurize to 3 bar and watch for a pressure drop that may indicate a leak. With the tubes pressurized we apply 3400 V to the wires and check the current flow (it should be a very small stable amount).