1. An Overview on Fragment Separators at Relativistic Energies Helmut Weick, GSI CERN secondary beams meeting CERN, 23 rd April 2009  In-Flight Fragmentation  B  -  E-B  Separation  Calculation of Resolving Power  Identification in Flight  Next Generation, Super-FRS  Energy-Loss of Relativistic Heavy Ions  H2 as fragment separator for SPS lead beam

2. rp-Process, Novae and X-ray Bursts r-Process and Supernovae Test of the Standard Model CKM-Matrix Parity Violation and Time Reversal in Atoms Superheavy Elements Fundamental Symmetries and Interactions Nuclear Astrophysics Structure & Dynamics of Exotic Nuclei Sp=0Sp=0 S n =0 Halo, Skin Nuclei New Shell Structure New Decay Mode 2 p-Emission Physics with Exotic Nuclei Applications

3. Production of Exotic Nuclei (Reactions, Cross Sections)

4. Scheme of RIB Production Methods

5. Fusion Fragmentation Fission Production of Exotic Nuclei

6. Dubna Acculinna COMBAS (Acculinna++) GSI FRS Super-FRS GANIL LISE3 SISSI+ALPHA VAMOS NSCL/MSU A1900, MSU FRIB ANL RIKEN RIPS BigRIPS Notre Dame Texas A&M MARS CNS CRIB RCNP Lanzhou RIBLL RIBLL2 Delhi KVI TRI  P World map of in-flight RI beam facilities JAEA HIMAC LNL Catania Sao Paulo Low-energy facilities LBNL Since 1984 @ LBNL by I. Tanihata et al. Florida State Univ.

7. Fragmentation Processes for 136 Xe beam predicted by ABRABLA thesis Antoine Bacquias, U. Strasbourg

8. Mass Distribution thesis Antoine Bacquias, U. Strasbourg ABRABLA Experiment

9. Longitudinal Momentum Distribution thesis Antoine Bacquias, U. Strasbourg exp. data V. Henzl, thesis, U. Prague Fermi momentum of bound nucleons Mom. transfer by evaporated nucleons Coulomb expansion in multi fragment. Bacquias’ model Experiment FRS@GSI Morrissey

10. Layout of In-Flight Fragmentation Facility NSCL at MSU more SISSI@GANIL, FRS@GSI, Big-RIPS@RIKEN, RIBLL@IMP Lanzhou, … K1200

11. Experimental Facility at GSI Production target Storage ring with detectors Separation Synchrotron Accelerator U ions up to 1 GeV/u detector setup implantation  -spectroscopy reaction target

12. B  -  E-B  Separation Method

13. Effect of degrader at different velocity MOCADI simulation

14. Effect of degrader at different velocity (2) MOCADI simulation fragment 190 W in achromatic separator, from 208 Pb beam, degrader d/R=0.1 B  slits = ± 0.36%, final slit = ± 3 mm small initial spot size (  x = 1 mm)

15. Requirements High Resolution Spectrometer Production Target low Z material for large hadronic cross section (  ~ A 2/3, Be, C) and low electronic energy loss (fewer electrons per atom). Imaging device with high momentum resolving power: R = D / (M  x 0 ), for given emittance R is proportional to area covered by beam in dipoles.  large dipole magnets, large acceptance beamline, good focusing, maybe higher order correctors target dipole degrader Thick degrader for large energy loss higher Z for lower nuclear absorption (Al, Cu) Shaped to preserve achromatism of overall system. High mechanical precision and surface treatment (  m)

16. Input for Simulation MOCADI LISE ++ codes:

17. Transfer Matrix Description Separator stage, D Degrader wedge, W ion-optical coordinates Full system = D2. W. D1 0

18. Analytical Description Resolution in mass, charge Degrader wedge coefficients Energy-Loss Straggling for achromatic separator (x|  v ) tot = 0 Resolving Power of one half

19. Phase Space Consideration Already achromatic system is kept achromatic with shaped degrader. condition:  p/p = const. This means absolute longitudinal momentum spread is reduced. Beam+Degrader not a closed system non-Liouvillean element. But we cannot really cheat Liouville. Shaped degrader couples to transverse emittance, this is increased by a factor, larger final spot size. In addition some multiple Coulomb scattering. target +  p/p degrader  x =  x 0 (x  x) (  ) -  p/p

20. Identification In-Flight B  = m/q  c 0 B  from magnet setting and position detectors at focal planes velocity from ToF between two scintillators or from Cerenkov Z from  E in ionization chamber, q=Z with strippers Total kinetic energy, in thick Si or scintillator, need to stop ions thesis V. Henzl, CTU Prague 2005. 238 U on H target at FRS

21. Separators for Projectile Fragmentation In-Flight NameE max (MeV/u)FacilityCountry A1900 90-160NSCL, MSUUSA FRS 1000-1900GSIGermany LISE-3, ALPHA 90GANILFrance BigRIPS 350 RIBF, RIKENJapan CRIB, RIPS 4-10CNS, RIKENJapan RIBLL I+II 1000IMS LanzhouChina Tri  p 10-70KVI GroningenThe Netherlands EN 70RCNP OsakaJapan COMBAS 50JINR DubnaRussia ACCULINA 40JINR DubnaRussia Super-FRS 1500FAIRGermany (planned) underlined = superconducting magnets, two degrader stages magnetic rigidity range B  = 1-18 Tm (20 Tm)

22. FAIR - Facility for Antiproton and Ion Research GSI today Future facility From synchrotron to storage rings. Pulsed beams to couple rings. 29 GeV protons for pbar production 34 GeV/u U 92+ for heavy ion collisions up to 1.75 GeV/u U 28+ for RIB production FAIR base line technical report, www.gsi.de/nustar for Super-FRS

23. Choice of Energy

24. The Super-FRS and its Branches target Pre-separator Main-separator B  = 20 Tm, superconducting magnets Mom. acceptance:  p/p = ± 2.5% Angular acceptance (h/v) = ± 40 mrad / ± 20 mrad Emittance after degraders up to  300  mm mrad

25. High Beam Power for Next Generation of RIB Facilities T_max ~ 1000 K d_max ~ 1 mm FAIR beam power 40 kW 6x10 11 U/pulse (50ns) FRIB up to 200 kW, deposited in small volume Target wheel, graphite for pulsed beams 30 nm x 30 nm Radiation damage, STM image T_max = 750 K Ø = 450 mm Beam catcher

26. Dose Rate by Activation 238 U beam at 1.5 GeV/u passing C-target and hitting BC1 FLUKA, E. Kozlova Near unshielded iron part of beam catcher 5 Sv/h with shielding bottle (30cm Fe) ~10  Sv/h concreteiron target

27. Fragments from Degrader BigRIPS Comissioning at RIKEN

28. BigRIPS commissioning 76 Ni Experimental Results Without degrader 76 Ni region not visible, with degrader still lots of lighter fragments.

29. BigRIPS commissioning 76 Ni Simulation with LISE++ Ratio: total rate / 76 Ni rate (S/N).

30. Energy-Loss of Relativistic Heavy Ions in Matter Large deviations from Bethe formula for heavy relativistic ions. C. Scheidenberger at al., PRL 73 (1994) 50. But well described by improved theory J. Lindhard, A.H. Sørensen, Phys Rev A53 (1996) 2443. included into ATIMA code http://www-linux.gsi.de/~weick/atima physics described in differential values + integration routines with spline files Important to tune Separator.

31. ATIMA code: Includes nuclear size effect, good description of very relativistic heavy ions up to E = 450 GeV/u. For even faster ions we would need electron-positron pairs (theory exists, A.H. Sørensen), and finally Bremsstrahlung. Energy Loss of very Relativistic Heavy Ions from H. Geissel et al., NIMB 195 (2002) 3.

32. Even larger deviations from Bohr/Bethe formula for heavy relativistic ions. C. Scheidenberger et al., Phys.Rev.Lett. 77 (1996) 3987.  2 = variance of  E Energy-Loss Straggling of Heavy Ions in Matter Again well described by theory J. Lindhard, A.H. Sørensen, Phys Rev A53 (1996) 2443. also included into ATIMA code. Also strong influence by nuclear size effect expected. No experimental prove yet, but H2 beamline with good focusing as required for separation, will show it.

33. The Program ATIMA Includes Theory for: Relativistic Heavy Ions, exact solution of Dirac Equation for collisions with electrons, J. Lindhard, A.H. Sørensen, Phys. Rev. A53, 2443. Nuclear-size effect (de Broglie wave length as short as nuclear radius). Fermi-density effect, R.M. Sternheimer, R.F. Peierls, Phys. Rev. B3, 3681. other corrections for lower energy Shell corrections, Polarisation (Barkas), Mean charge state below 10 MeV/u empirical formula (J. Ziegler). Code: FORTRAN subroutines also for integration, and Java-Shell, or implemented in other programs: MOCADI, LISE ++, Heavy Ion transport code PHITS, plans for Geant 4, not yet in FLUKA Developed at GSI by: Thomas Schwab, Hans Geissel, Christoph Scheidenberger, Peter Malzacher, Jörg Kunzendorf, Helmut Weick http://www-linux.gsi.de/~weick/atima

34. H2 as Separator Basic properties: Dispersion in one stage: (Y|  ) = 2.9 cm/%, (Y|Y) = 0.96 overall achromatic system with two dispersive stages degrader 500 m target

35. Resolution of H2 separator 208 Pb beam 45.7 GeV/u on C target B  cut, fragment beam has  p /p = 1.6% after target.

36. Resolution of H2 separator 208 Pb beam at 45.7 GeV/u, Cu degrader d/R=0.1 (450 g/cm 2 ) Position at achromatic image plane. But this degrader is too thick! survival probability ~ 3x10 -6, (Pb 2x10 -4 ?) no apertures real apertures

37. Summary  Fragmentation in flight is a rich source for rare isotopes.  To have useful beams we need to separate, at higher energy at best with B  -  E-B  method.  Resolution depends on separator resolution and degrader properties, relative energy loss.  New separators for high intensity beam target, beam dump issues, activation Super-FRS at FAIR with two degrader stages.  Improved theory for energy-loss of relativistic heavy ions.  H2 as Fragment Separator is in principle possible.

38. Charge Identification at SPS Scheidenberger et al. PRL 88, 042301 (2002). Detection by ~50 cm long IC with 4 anodes (100 mg/cm 2 Ar). Pb beam at 158 AGeV after passing a target.

39. Separation B  Cut only 10 9 208 Pb -> ~ 10 8 fragments calculated at 2.5 GeV/u but with thick target

40. Separation with Degrader 10 9 208 Pb -> ~ 10 6 fragments Reactions in degrader not considered (calculated at 2.5 GeV/u but with thick matter)

41. Separation with Degrader 10 9 208 Pb -> ~ 10 6 fragments With reactions in degrader (calculated at 2.5 GeV/u but with thick matter)

42. Hans Geissel, Super-FRS Evaluation 08 Comparison of Projectile Fragment Separators Worldwide Separator  p/p Angular Acceptance (  x,  y ) Solid- Angle B  max Resolving Power R16/R11 Intensity Primary Beam 238 U per sec %mrmsrTm(2x 0 =1 mm) Super- FRS 580, 403.22030762xE11 FRS230, 30.918 3131 (2x 0 =2,7mm) 1xE9 Big-RIPS680, 1008.09 1 st stage 1290 2 nd stage 3300 (2x0=1mm) 6xE12 A190058.0629001xE9 RIPS680, 805.05,815006xE12