Targets for the proposed SuperFRS at GSI Klaus
- Slides: 10
Targets for the proposed Super-FRS at GSI Klaus Suemmerer, GSI Darmstadt Properties of SIS-100/200 beams Target design for slow extraction Target design for fast extraction Handling concepts
Collaborators: GANIL: F. Landre-Pellemoine, W. Mittig, P. Roussel-Chomaz GSI: K. H. Behr, V. Chiskine, H. Geissel, B. Kindler, J. Kohuharova, B. Lommel, H. Weick, Uni Frankfurt: N. A. Tahir Uni Giessen: M. Winkler RAS St. Petersburg: M. Yavor
Properties of SIS-100 beams Ion beam: 1 Ge. V/nucleon 238 U, 1012 ions Beam spot: circular, Gaussian distribution, = 1 -2 mm Extraction modes: slow (seconds) or fast (50 ns) Target material: C (graphite), Tsubl= 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 (k. J) 2. 9 5. 8 11. 6 17. 4 Worst case!
Target concept for slow extraction 1012 U ions/s, “fast” rotation Insulating core up to r=10 cm to prevent damage to bearings
Temperature profiles for different target thickness 1012 U ions/s, “fast” rotation Worst case! All temperatures can be handled easily!
Equilibrium temperature distribution 2 g/cm 2 C, 60 rpm, after 100 s T/K 1810 t = 60 K 1750
Technical solution for a C target wheel C target (6 mm central part) Tmin = 590 C Tmax = 1376 C Weight = 650 g Rext = 105 mm Rint = 17 mm Thickness = 19 mm
Requirements for fast extraction 1012 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 target explodes after ca. 50 ns!
Possible solutions for fast extraction increase beam spot size: + lower specific power - worse resolution x = 1 mm y = 12 mm R=0. 65*Ropt thermal expansion? target destruction? continuous target replacement? e. g. liquid Li?
Handling of activated components in a high-radiation area FRS-solution: industrial robot no electronic components installed at S 1 -focus of FRS involves tool development (holders, media connection) planned for present FRS-target suitable also for Super-FRS?
