Technical Design Report Super Fragment Separator

DRAFT
Table 2.4.4: First-order matrix elements for the Ring-Branch (RB) 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 MF6 MF7
(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 -0.5
(a, δ) 0.09 0 0.06 0
(y, y) -1.96 2.00 2.00 -1.54
(y, b) 0 0 0 0
(b, b) -0.51 0.50 0.50 -0.65
drift length 4.0 6.0 4.0 6.0
The Ring-Branch has been coupled in ion-optical calculations and simulations via a transport line
to the Collector Ring, as illustrated in Figure 2.4.12. From the experience of the present FRS-ESR
facility, such coupling is an essential part for reaction experiments with stored exotic nuclei.
Figure 2.4.12: Layout of the Ring-Branch of the Main-Separator connected with the Collector Ring CR.
The transmission of separated fragments from the Super-FRS into the storage rings, like the CR, is
an important issue. For characteristic examples the fragment production, separation and transport
into the collector ring have been simulated with the MOCADI code [6]. The transmission (T) was
calculated in two parts: up to the exit of the Super-FRS (MF7) and stored into the CR. Realistic
target and degrader thicknesses optimized for higher rates were used for separation and slowing-down
to 740 MeV/u. After this separation the beam still is not completely monoisotopic but
will be with the additional m/q-separation of the CR. Four cases were selected to give a representative
overview. Table 2.4.5 shows the emittance of the fragment beams after separation at MF7.
The values are defined by two sigma values of the position and angular distribution. The transverse
emittance is much increased due to the slowing-down and straggling in the degraders whereas the
momentum spread stays about the same. The fragment beam was matched to the foreseen acceptance
of the CR (∆p/p = ±1.75 %, εx = εy = 200 mm mrad).
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