In the beam plot of the Main Separator shown, the end focus at FHF1 is chosen as 7.5 m beyond the end of the last quadrupole in the HEB. This large distance is needed to transport the RIB through the thick shielding wall of the R3B cave up to the next quadrupole triplet within.
The High Energy Branch continues on to the R3B experiment. The R3B experiment, in general, needs high energy RIBs. So the magnets in this branch of the Super-FRS must be capable of focusing beams up to almost the maximum magnetic rigidity of 20Tm.
The table below gives the 1st-order transfer matrix elements at the focal planes in the High-Energy Branch of the Main-Separator. The linear dimensions x and y are in meters, the angles a and b in radians, and the momentum deviation d as a fraction of the nominal (reference) value. The “path length” is from the Super-FRS target. FHF1 is 7.5 m from the end of the last quadrupole, FHF1QT32.
Path length (m)