096 – Controlling the LHC Beam
In this fourth (and for the time being, last) episode in the series on physics at CERN we look at the LHC from the perspective of the beam producers, and more specifically, from the perspective of the control system for the LHC. To this end, we first talk to Vito Baggiolini, a software engineer in the controls group, and then we talk to Felix Ehm, a technical engineer for the beam control system. In the episode we recap what the LHC does and how it does it (you may want to re-listen to Episode 30 on the LHC), discuss the hardware elements used for beam control, some of the safety and security systems, as well as about the software aspects of the system.
I would like to thank Chris Mann from Mannmade Productions for letting me use the soundtrack of his LHC video in this episode.
After recording the episode, Vito noticed a couple of errata in the conversation:
- 03:35 LEP was shutdown at the end of 2000, not in 2003
- 04:45 CLIC study: the CLIC study facility at CERN is small (150m), only a real linear collider will be 30 km or longer
- 07:30 There are not 5 but 6 LHC experiments (Atlas, CMS, Alice, LHCb, TOTEM, LHCf)
- 28:53 Beam dump material is graphite framed in concrete, there is no copper.
- 30:00 Loosing the beam in an uncontrolled manner would not “destroy all our precious magnets”, but it could destroy a few magnets and other precious equipment.
- 53:12 Real-time feedback is given only to corrector magnets, not all. The beam is instable (like a helicopter) only during the ramp.
- 56:00 In 2011 we have had magnet quenches, but only at low energy levels, not at high energy.
- 56:50 UFOs = Unidentified Falling (not Flying) Objects
- 59:30 You have to take a key to show if your inside or outside the tunnel (not the inside or outside the beam)
And, as usual, here are some links:
- Controls Group
- lhc-facts.ch – very good German website on the LHC
- LEP (Large Electron-Positron Collider)
- CLIC (Compact Linear Collider)
- Mass in Special Relativity
- Right-Hand Rule
- C (programming language)
- C++ (programming language)
- Linux OS
- CORBA (Common Object Request Broker Architecture)
- Java Remote Method Invocation (RMI)
- Java Message Service (JMS)
- Synchrotron radiation
- Quadrupole Magnet
- Dipole Magnet
- ATLAS Experiment
- SM-18 Pictures