1.  Properties of SIS-100/200 beams  Target design for slow extraction  Target design for fast extraction  Handling concepts Klaus Suemmerer, GSI Darmstadt Targets for the proposed Super-FRS at GSI

2. Collaborators: F. Landre-Pellemoine, W. Mittig, P. Roussel-ChomazGANIL: GSI: K.H. Behr, V. Chiskine, H. Geissel, B. Kindler, J. Kohuharova, B. Lommel, H. Weick, Uni Frankfurt: N.A. Tahir M. Winkler Uni Giessen: RAS St.Petersburg: M. Yavor

3. Properties of SIS-100 beams Ion beam: 1 GeV/nucleon 238 U, 10 12 ions Beam spot: circular, Gaussian distribution,  = 1-2 mm Target material: C (graphite), T subl = 3900 K Target thickness: 1 – 6 g/cm 2 ( 18% - 67% interaction probability) Target thickness  1 g/cm 2 2 g/cm 2 4 g/cm 2 6 g/cm 2 Dissipated energy  (kJ) 2.95.811.617.4 Extraction modes: slow (seconds) or fast (50 ns) Worst case!

4. Target concept for slow extraction Insulating core up to r=10 cm to prevent damage to bearings  10 12 U ions/s, “fast” rotation

5. Temperature profiles for different target thickness All temperatures can be handled easily!  10 12 U ions/s, “fast” rotation Worst case!

6. 2 g/cm 2 C, 60 rpm, after 100 s  t = 60 K T/K 1810 Equilibrium temperature distribution 1750

7. R ext = 105 mm R int = 17mm Thickness = 19mm C target (6mm central part) Tmin = 590 C Tmax = 1376 C Weight = 650 g Technical solution for a C target wheel

8. Requirements for fast extraction target explodes after ca. 50 ns! 10 12 U ions/50 ns on: 3.4 g/cm 2 Li target P = 166 GW 5.5 g/cm 2 Pb target P = 200 GW

9. Possible solutions for fast extraction  increase beam spot size: + lower specific power - worse resolution  x = 1 mm  y = 12 mm R=0.65*R opt  thermal expansion? target destruction?  continuous target replacement? e.g. liquid Li?

10. Handling of activated components in a high-radiation area  FRS-solution: industrial robot  no electronic components  installed at S1-focus of FRS  involves tool development (holders, media connection)  planned for present FRS-target  suitable also for Super-FRS?