Chorus Picture Book

Picture Book

Collaboration and Detector in 1993
End-of-run party 1994
Aircore Magnet
Best Shift's Bottle 1995
Aircore small-scale prototype
Chorus-Cern group Dec 4th 1995
Chorus-Cern group Dec 31th 1995
"Nagoya Traditions" (Ubaldo, Roberta, Tonino, Giancarlo, ??)
"Before the Bath, 1" (K.Niwa, Juergen and Mehmet)
"Before the Bath, 2" (K.Niwa, Juergen, Mehmet and Gustaaf)
Map of CERN/Chorus

Excursion to the West Area Neutrino Facility (T9 area):

Some 10^13 protons, accelerated to 450 GeV/c during one cycle of the Super Proton Synchrotron (CERN-SPS) arrive at the BCT (Beam-Current Transformer), where the beam current is measured. (Watch the heavy corrosion, caused by radiation-induced Ozone) The proton beam is transported through bending magnets and quadrupoles, to the Target area (inside Yellow and Green shielding), containing the Beryllium target and Copper and Aluminium collimators. Secondary Pions and Kaons travel through air towards the Horn, a paraboloid magnet, pulsed during 6 milliseconds, with 100 kiloAmperes at 5.4 kiloVolts twice in every SPS spill (This means 0.5 GigaWatt of power, assuming an electricity price of 10 centimes Suisses per kWh, every pulse costs CERN another 10 centimes...).

The Pions and Kaons travel through the first Helium-pipe(#1) towards another poraboloid magnet, the Reflector, that refocusses lower-energy particles that were too much deflected in the Horn. This one operates at 120 kA and 5.2 kV, adding another 12 centimes to the cost per pulse.

A second Helium-pipe(#2) follows, transporting the beam to the entrance of the Vacuum decay tunnel with a length of 290 meters and a volume of 412 cubic meters. The decay tunnel is closed by a 2 mm thick Titanium foil. For safety reasons (implosion risk) the tunnel is also closed with a thick circular steel plate, that is interlocked with the access system. It is automatically removed when run-conditions have been established.

Be aware: this excursion has added about 120 microSieverts to your accumulated virtual radiation dose! (yearly dose from natural sources is about 5 milliSieverts, so it is about one extra weekly dose, or half a transatlantic fligth)


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JV / 29 Feb 1996