The WEDGE program was produced for helping the MOCADI program. For separating a seconday beam from a large mount of contaminant beams produced with the projectile fragmentation method, the magnetic rigidity analysis and energy-loss analysis are used, usually. In the method, a wedge-type degrader is inserted at a dispersive focus in an achromatic ion optical system. This program calculates wedge angles of the degrader for the achromatic and monochromatic modes. The achromatic mode gives the smallest beam size, therefore it was used for secondary reaction experiments. The monochromatic mode gives a broader beam size but smallest beam energy deviation, therefore it was used for the ion implantation experiment.

How To use WEDGE program

The WEDGE program was installed in the GSI alpha-cluster. Since the program uses the energy loss spline data calculated by ATIMA, it is necessary for executing the command procedure kp2$root:[iwasa.mocadi] (as ``@kp2\$root:[iwasa.mocadi]setup'') before using WEDGE. The command procedure sets the following logical names and creates the command WEDGE as well as the command MOCADI.

$ def/nolog mocadi_data kp2$root:[], kp2$root:[iwasa.mocadi.spline]
$ def/nolog mocadi_exe kp2$root:[iwasa.mocadi.exe]
$ wedge :==$mocadi_exe:wedge.exe
$ mocadi :==$mocadi_exe:mocadi-34-20.exe

$ wedge
***                                          ***
***  Wedge angle calculation                 ***
***                                          ***

***** input following parameters *****

6:FRS(S1 deg),7:FRS-ESR(S1 deg),8:FRS-CAVB(S1 deg),
9:FRS-CAVC(S1 deg),10:other(S1 deg)
[1] ? 
Choose optical system. When you type 1, the FRS standard optics is chosen.

[1] ? 1

matrix elements
dispersion of    TA-S2  [cm/%]=-6.821279e+00
dispersion of    S2-S4  [cm/%]=6.026345e+00
magnification of S2-S4        =8.834627e-01

Please input parameters. If you don't type parameters, the default values are selected.

mass of fragment [amu]       [8.024606] ?
charge of fragment           [5.000000] ?
energy of fragment [MeV/u]   [308.500000] ?
charge of degrader           [13] ?
degrader thickness [mg/cm2]  [5000.000000] ?
momentum acceptance [%]     [1.000000] ?
  sirera:  energy loss table MOCADI_DATA:*-Al.dat was read

      Energy    momentum   range
      [MeV/u]   [MeV/u/c]  [mg/cm2]
TA-S2  308.50     818.48 2.210920E+04
S2-S4  264.14     749.57 1.710920E+04

Al degrader   :  thickness        wedge angle
achromatic    :     5000.22 mg/cm2     -18.8120 mg/cm3    6.96741 mrad
monochromatic :     5001.59 mg/cm2     -93.0316 mg/cm3   34.45616 mrad

                                             ^               ^
                                    OUTPUT FOR MOCADI  OUTPUT FOR degrader_cal

PLOT(Yes/No) ?
When you type YES, the WEDGE program make a topdrawer file for ploting degrader thickness as a function of horizontal position at the dispersive focus.

continue(Yes/No) ?


I would like to thank H.Irnich and H.Geissel to provide thier programs to calculate wedge-angles Many thank are due to P.Malzacher and C.Scheidenberger to provide splines calculated by ATIMA-1.0 25th Oct. 1996