Pre-Separator

 

The Pre-Separator must be capable of focusing beams up to the magnetic rigidity of 20Tm.

In the figure 1, the beam plot with 3rd-order ion-optics of the Pre-Separator is shown.

 

/fileadmin/Kernreaktionen/Preseparator.jpg

The table below gives the calculated 1st-order transfer matrix elements at the focal planes in the Pre-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.

1st-order transfer matrix elements at the focal planes in the Pre-Separator

Matrix element

FPF1

FPF2

FPF3

FPF4

(x,x)

-2.94

1.72

-2.75

2.00

(x,a)

   

0.03

 

(x,d)

4.39

-2.58

4.07

 

(a,a)

-0.34

0.58

-0.37

0.50

(a,d)

0.52

 

0.53

 

(y,y)

-5.65

-2.07

4.23

1.52

(y,b)

2.65

-0.05

-2.60

0.06

(b,b)

0.01

-0.46

0.03

0.57

Path length (m)

22.00

35.60

49.34

71.50

In the figure below in the upper panel is shown calculated phase space in the dispersive middle focal plane of the Pre-Separator, FPF2, for a beam of three different momenta of ∆p/p = ±2.5 % without (red distributions) and with (blue distributions) correction of image aberrations by sextupole magnets. In the lower panel is presented corresponding angle-position phase space at the achromatic focal plane FPF4.

/fileadmin/Kernreaktionen/sextupole-correctn.jpg