Technical Design Report Super Fragment Separator

DRAFT
Figure 2.4.16: Ion-optical layout of the energy buncher, its main characteristics are: Bρmax�= 7 Tm, εx = 300
mm mrad, εy = 200 mm mrad, Φx = �Φy = 20 mrad, ∆p/p = ±2.5 %, (transverse and longitudinal acceptance).
Under these conditions a momentum resolving power of R = 600 can be achieved. The quadrupole magnets
are indicated with yellow yokes, the hexapole magnets in red.
Figure 2.4.16 illustrates the ion-optical layout of the energy buncher. The spectrometer consists of
a dispersive ion-optical stage with a large split dipole magnet system, quadrupole and hexapole
magnets. The magnetic quadrupole triplet in front of the dipole magnet is needed to properly illuminate
the field volume of the dipole magnet to reach the required resolving power and to focus
the secondary beam onto a monoenergetic degrader. The quadrupole triplet behind the
monoenergetic degrader guides the exotic nuclei into the gas cell or any other detector array.
It is a valuable and attractive experimental opportunity to use the energy buncher also as a
high-acceptance spectrometer for particle identification after secondary reactions via magnetic
rigidity analysis and tracking. The identified secondary reaction products can be measured in
coincidence with gamma spectroscopy at the secondary target at MF10. For this purpose the four
units of the large 90-degree dipole magnet are separated in two stages. The first unit alone has a
higher momentum acceptance than the full buncher system. The ion-optical mode of this spectrometer
is presented in Figure 2.4.17. In addition, an experimental scenario has been simulated to
study knock-out reactions of 132 Sn fragments in coincidence with gamma-ray spectroscopy at
MF10. The simulated mass distribution of the secondary fragments demonstrates the achieved
resolving power obtained via particle tracking.
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