Pictures from the SuperHilac
.
The Drift tubes down the center of prestripper tank number 2
A the right of the picture there are 3 loops. These loops were used to put RF power into the accelerator tank. RF power was generated by means of three RF Amplifier carts. These amplifier carts relied on very large vacuum tubes and very high voltages. The 3 loops on the left are for tuning the radio frequency of the RF tank. The frequency of the SHilac was 70.285mhz.Down the center are the drift tubes. Drift tubes are magnets that have a hole in the center. They are used to accelerate and keep the particle beam going in a straight line. These particular drift tubes operated with about 100amps of current. Pulsed RF field was used to accelerate the electron beam.
The picture above is the Crockroff Walton powered EVE injector house. This is where the elements of the periodic table were vaporized and then accelerated through the SHilac. This acceleration was done by means of an ion source. The Ion source had several elements. The arc, the sputter the extractor and the filament. Each of these was powered by a separate high voltage high current power supply. After the accelerated element left the injector house it would pass through an accelerator column that would further accelerate the element. The element would then be steered by several magnets and accelerated through the 8 RF tanks of the SHilac.On the output side the accelerated element would reach 8.5mEv per nucleon. It would then be steered by several different types of magnets down to the experimenter-where they carried out their research.
Above is a picture of the 750MeV Able Injector Crockroff Walton Stack. Mechanical engineer Gerd Bershing stands at its base. Gerd was about 5'10" so you can imagine just how massive this thing was. The brown cylindrical shaft at Gerd's back is the drive shaft for the injector AC power. This shaft was driven by a 200HP motor which in turn drove a 60hz and a 400hz alternator that provided injector house power. This on board power distribution system was necessary because when the injector was running for experimenters the outside of the injector house would float at about 675Kv above ground. The humidity in the building was kept intentionally low because when the humidity would get to high lightening bolts could be seen between the outside of the injector house and the aluminum wall of the building. It was very impressive when the lights were turned out.
Above are the drift tubes inside of one of the SHilac's accelerator tanks. From the size of them I would guess that they are at the exit end of the machine. These drift tubes are on while the ones at the front end of the accelerator were very small. This was because the entrance of the Hilac the accelerated beam was moving very slow. At the exit the beam was moving faster so the drift tubes were longer. There ware also fewer at the exit of the machine. The SHilac prestripper-tanks 1&2- had about 140 drift tubes while the postripper-tanks 3-8- had 79 drift tubes.
All pictures on this page are courtesy of the Lawrence Berkeley National Laboratory Photo Archives.
