Industrial Liaison Office

Reduce text Increases text RSS Elettra Print this page Send by email Linkedin YouTube

Bunch Length Magnetic Compressor

Accelerator Building Blocks

Relatively long bunches are typically produced by photo-injectors, with peak current in the range of 10 - 80A. Thus, the bunch is compressed in one or more Bunch Length Magnetic Compressors (BC) to increase the peak current, by a total factor which is normally greater than 10.


In a multi-stage compression scheme (i.e. two chicanes or more are included in the accelerator layout), the location and compression factor of the individual chicanes must be tuned in order to minimize the electron beam 6-dimensional emittance dilution in the presence of space charge forces and wake fields. In FERMI, the nominal electron energy at BC1 is 300 MeV, and 600 MeV at BC2.


The magnetic field quality and control of the dipole and quadrupole magnets ensures no degradation to the electron beam transverse emittance for the entire bending angle range.






Main mechanical specifications
Bending angle range 0-7 deg
Central drift displacement range 0-367 mm


  BC 1 BC 2
Nominal Energy 300 MeV 600 MeV
Number of Dipoles 4 4
Number of Quadrupoles 2 2
Curvature angle 0.120 rad 0.120 rad
Curvature radius 7.113 m 5.914 m
Magnetic field at center (nominal energy) 0.117 T 0.333 T



  • The Bunch Length Compressor is delivered as a turnkey system.
  • Optional: The control system may be integrated on request.


Developed for the FERMI@Elettra Project