What are these yellow pipes?
http://cdsweb.cern.ch/record/1436155/fi ... 2_3108.jpg
Yellow Pipes
Re: Yellow Pipes
They're beam loss monitors (tip: there's a label just behind them!).
Specifically, they are ionisation chambers. They work on the same principle as a Geiger counter: a tube of gas is subject to a high voltage (thus the warning signs). When any particles from the beam hit the beam pipe, they create a shower of other particles, which in turn pass through the ionisation chamber, knocking off some electrons from some of the gas atoms inside. The electrons and ions are then pulled apart by the high voltage, creating a current which is measured, and which ends up as a little green or blue line on the LHC dashboard.
Specifically, they are ionisation chambers. They work on the same principle as a Geiger counter: a tube of gas is subject to a high voltage (thus the warning signs). When any particles from the beam hit the beam pipe, they create a shower of other particles, which in turn pass through the ionisation chamber, knocking off some electrons from some of the gas atoms inside. The electrons and ions are then pulled apart by the high voltage, creating a current which is measured, and which ends up as a little green or blue line on the LHC dashboard.