Dipole Visible Synchrotron Radiation Monitors

General description :

The visible part of the synchrotron radiation produced in a total of 9 dipoles of the ESRF injector is now extracted to obtain simultaneous images of the electron beam profile at these locations. This is done at each injection and in a non-destructive way to the electron beam.

The first transferline (180MeV) contains three monitors on the 2 dipoles (0.38T) and the injection septum magnet.

The Booster accelerator has one monitor that allows the profile measurement at any moment in its 50ms acceleration cycle by timing the internal camera shutter.

In order to equip each of the 5 dipoles (0.9T) in the 2nd transferline (6GeV) with such a monitor, a compact and low-cost light extraction system was added at the end of the (non-modified) dipole vacuum chamber.

All systems use low-cost commercial CCD cameras, sufficient light is produced at beam-currents a factor ~100 below nominal values.

The video images are displayed in the Control Room operator at each injection, giving a quick & complete view of injection conditions all along the injector path. 

References & links of relevant papers and presentations :