Technical Design Report Super Fragment Separator

DRAFT
Figure 2.4.14: Ion optical layout of the Main-Separator of the Low-Energy-Branch. Shown are the envelopes
of a 40 mm mrad beam in x direction (upper half), y direction (lower half) and the dispersion in case of
a ±2.5 % momentum deviation (dashed line). The ion-optical configuration beyond MF3 has been modified.
One focal plane has been removed and as a consequence the bending direction of the last dipole stage has
been changed.
Table 2.4.6: First-order matrix elements for the Low Energy Branch of the Main-Separator. The linear
dimensions for x and y are in [m], for the angles a and b in [rad], and for the momentum deviation δ in parts
of the nominal value.
Matrix
Element
MF1 MF2 MF3 MF9
(x, x) -4.23 1.93 -4.23 -2.00
(x, a) 0 0 0 0
(x, δ) 6.50 -5.93 6.50 0
(a, a) -0.24 0.52 -0.24 -0.50
(a, δ) 0.09 0 0.10 0
(y, y) -1.96 2.00 -1.96 -1.89
(y, b) 0 0 0 0
(b, b) -0.51 0.50 -0.51 -0.53
drift length 4.0 6.0 4.0 6.0
The momentum spread of the fragment beam can be reduced if the resolving power guarantees that
the spot size at the degrader is dominated by the dispersion and not by object magnification and
aberrations. Since the emittances of the fragment beams are inevitably large, a large-aperture
spectrometer with the necessary high resolving power is needed to compensate for the energy
spread.
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