Within the Accelerator division, the operations section is responsible for the  accelerator complex. The accelerator complex consists of:

  • a linear accelerator which accelerates electrons up to 100 MeV; 
  • a booster synchrotron where the electrons are further accelerated up to 3.0 GeV; 
  • and the storage ring, where electrons are stored and emit synchrotron radiation, which is used at the beamlines.

During operation of the beamlines, the accelerators run 24 hours a day, 7 seven days a week. About 75% of the time that the accelerators are powered up is dedicated to providing beam to the beamlines. The rest is dedicated to improving the quality of the beam as well as the further development of the accelerators.

The main objective of the operations section is to deliver a high quality and stable beam to the scientists that come to perform experiments at ALBA.

The storage ring has an orbit feedback system, which is able to keep the orbit stable to within less than 1 µm in both planes. The figure below shows the movement of the beam as measured on the BPMs (Beam Position Monitor) during a 24 hours period. The RMS (Root Mean Square) values of the beam distortion are 0.5 µm in the horizontal plane and 0.2 µm in the vertical plane.

Figure of the orbit feedback system used at the ALBA storage ring.

At present the storage ring is operated in the so called top-up mode. In this mode, continuous injections of less than 1 mA maintain the current in the storage ring at a near-constant level. The advantage of top-up operation is that the heat load down the beamlines is constant and no thermal drifts cause disturbances to the measurements.

Figure of the Top-up Mode of the Accelerators operation.  Decay mode of the Accelerators operation.  
                                              Top-up operation                                                       Decay mode operation (up to 2014)