1. K.U. Leuven Future Physics with EURISOL Piet Van Duppen Instituut voor Kern- en Stralingsfysica K.U. Leuven, Belgium EURISOL town meeting CERN, Geneva, November 2006 Experimentalists look to the (recent) past to learn about future: evolution of the physics questions/cases driving the RIB research examples of recent RIB experiments as a basis of what can be expected An observation: chart of nuclide 1966, one of the “mothers” of the chart of nuclide

2. K.U. Leuven I. Bergström: “Introduction to the Lysekill Symposium”, 1966 B. Rudstam, Nucl. Instr. and Meth. 38 (1965) 282 1966 Neutron number Proton number ~2000 Increase in the understanding of the atomic nucleus or nucleosynthesis since 1966 is far more compared to the increase of the number of discovered isotopes Progress in producing RIB is substantial but a wide region remains unexplored will certainly intrude in this “terra incognita” increase in intensity by one to three orders of magnitude is expected this corresponds to one to three isotopes further out of stability theoreticalexperimental Intertwined theoretical and experimental activities better quality beams (purity, intensity, ion optical properties, time properties) production and study of “critical” nuclei novel instrumentation (detection systems, separators, spectrometers,...) due to The physics outcome of will be far more than what might be concluded from the number of new isotopes that will be discovered.

3. K.U. Leuven under revision The physics questions for nuclear-physics research The physics questions for RIB research

4. K.U. Leuven What are the limits for the existence of nuclei? How does the nuclear force depend on the proton-to-neutron ratio? How can collective phenomena be explained from individual motion? Is it possible to explain complex nuclei on the basis of simple building blocks? What is the origin of the elements? …. Production, study and use of atomic nuclei with extreme proton-to-neutron ratio: EXOTIC NUCLEI European Separator On-Line Radioactive Nuclear Beam Facility

5. K.U. Leuven The HIE – ISOLDE Physics Report to be published 2007 “the physics cases”

6. K.U. Leuven More Specific Physics Questions Evolution of shells: single-particle properties, specific components of the residual interaction, correlations,... Shapes: individual versus collective nucleon behavior, shape coexistence, shape- phase transitions/critical point symmetries, giant resonances,... Isospin symmetry Limits of existence of nuclei: halo’s and skins, neutron- and proton drip line, the heaviest elements exotic decay modes (e.g. two-proton decay, neutron radioactivity) Nuclei at very high spins, extreme density and temperatures study of the nuclear equation of state by varying the N/Z ratio: isospin degree of freedom Fundamental symmetries and interactions  -decay probes Nuclear Astrophysics - Nucleosynthesis rp-process, r-process,... Physics questions and cases are well established, but probably the physics cases will evolve. Physics questions and cases are well established, but probably the physics cases will evolve. Experience learns that surprises will show up and experiments will be performed beyond our imagination. Experience learns that surprises will show up and experiments will be performed beyond our imagination.

7. K.U. Leuven “Physics with radioactive beams” W. Nazarewicz,- Nuclear Physics News, 6 (1996) 17 Mother of the Nuclear Chart with Physics Bullets Future Physics  A subjective choice of examples of what has been achieved over the last 5 years at ISOL facilities as a glimpse of what the“Future Physics” at might look like (overlap with the talk of Rauno Julin and others yesterday) 1996

8. K.U. Leuven  D. Lunney,- Rev. Mod. Phys. 75, 1021 (2003) half life (seconds)  Time-of-Flight TOF Schottky RF-Spectrometer Penning Trap TOF Isochronous LEBIT Mass measurements at ISOL facilities and In-Flight facilities mass measurements with higher precision (for “critical” nuclei) and of isotopes with shorter half-lives (test of mass models for a more reliable extrapolation towards the drip lines, highlight correlation in the ground state,...). Ion manipulation technologies: purification and improving ion optical properties (use beyond original expectations) E: 50 keV  ~ eV complementary between ISOL and In-Flight

9. K.U. Leuven Fundamental Interactions Testing the unitarity of the Cabibbo Kobayashi Maskawa matrix Precision half-life measurement of 38 Ca super allowed 0 + -0 +  decay B. Blank,- ISOLDE experiment Accumulation CoolingEjection – TOF selection Penning trap assisted spectroscopy Penning trap assisted spectroscopy (ISOLDE, JYFL) T 1/2 = (450.0  1.6) ms separation of molecules: 38 CaF+ (ion source chemistry) accumulation in REX-trap TOF selection of A = 55  pure source combined with up-to-date instrumentation  a new generation of decay spectroscopy and in- trap spectroscopy experiments new and high-precision data far off stability. accuracy < 0.4% E: 50 keV  ~ eV

10. K.U. Leuven Shape Coexistence In-Source Laser Spectroscopy on light Pb (Z=82) Nuclei (ISOLDE) 186 Pb Triple Shape Coexistence at Low Energy:  -decay studies: A. Andreyev et al., Nature 405 (2000) 430 in-beam studies (bands and life times): T. Grahn,- PRL97 (2006) 062501 H. De Witte,- PRL98 (2007) 112502 In-source laser spectroscopy: E ~ 50 keV

11. K.U. Leuven In-Source Laser Spectroscopy on light Pb Nuclei (ISOLDE) Pb isotopes stay essentially spherical, deviation from liquid drop is due to strong sensitivity to correlations in the ground state wavefunction. H. De Witte,- PRL98 (2007) 112502 182 Pb T 1/2 =55 ms ~1 pps laser instrumentation: new beams, ground and isomeric state properties, polarization, isomeric beams (use beyond original expectation)

12. K.U. Leuven Halo nuclei β-decay of 11 Li: implantation-decay correlations (TRIUMF, LLN)  -delayed ion emission using post-accelerated RIB ( 11 Li) beams implanted in highly segmented Si detectors Information on the overlap between wave functions of mother and daughter states Experiment: efficient, precise normalization, suppression of beta signals (small pixels) ( D. Smirnov et al., NIMA547 (2005) 480, Louvain-la-Neuve RIB ) Determine: branching ratios, energy of the emitted ions 11 Li beam (1.5 MeV/u) mother decay daughter decay Si pixel: 75x300x300  m E ~ 1 MeV/u 11 Li (cfr. talk by O. Tengblad yesterday)

13. K.U. Leuven Branching ratio 9 Li+d: 1.23(12) x 10 -4 V a : resonance in 9 Li + d V b : bound state in 9 Li + d V C : only (Coulomb-distorted) plane wave [Baye et al, PRC 74, 064302 (2006); Zhukov et al., PRC 52, 2461 (1995)] Deuteron emission in the β-decay of 11 Li (TRIUMF) R. Raabe et al. to be published : high purity, post-accelerated, precise beam energy 11 Li 3/2 - T 1/2 =8.2 ms

14. K.U. Leuven Nucleosynthesis Strength of the 18 F(p,  ) 15 O reaction at E c.m. = 330 keV (HRIBF) Strength of the 26g Al(p,  ) 27 Si reaction at E c.m. =184 keV (TRIUMF) E ~ 0.2-1.5 MeV/u C. Ruiz,- PRL 96 (2006) 252501 18 F: 2 10 5 pps “The results of the present work indicate that the 18 F(p,  ) 15 O reaction rate is lower than previous estimates by a factor of 2.” D.W. Bardayan,- PRL89 (2002) 2625 01 18 F(p,  ) 15 O 26g Al: 2.5 10 9 pps  35 +- 7  eV 26g Al(p,  ) 27 Si “It confirms that classical novae are likely sites for the synthesis of a fraction of the Galactic 26g Al....” (see also LLN-RIB, SPIRAL-GANIL, REX-ISOLDE)

15. K.U. Leuven N=50 Z=28 N=40 p 1/2 g 9/2 f 5/2 Stability of Z=28 and N=50 towards 78 Ni Onset of collectivity for Z>28 Shapes and Shells Coulomb excitation (REX-ISOLDE) I. Stefanescu,- PRL 98 (2007) 122701 J. Van de Walle,- PRL (2007) to be published E ~ 3-5 MeV/u (see also SPIRAL-GANIL, HRIBF)

16. K.U. Leuven counts energy (keV) 78 Zn 108 Pd 730 keV: 2 + -0 + 1492 keV: 2 + -0 + 0 500 1000 1500 2000 800 600 400 200 0 80 60 40 20 0 0 500 1000 1500 2000 80 Ga 78 Ga 108 Pd x 50 laser on laser off 80 Zn (T 1/2 =0.5 s, 2.79 MeV/u) @ 108 Pd (2.0 mg/cm 2 ) Intensity = 3000 pps Purity = 43 (5) % used beyond original expectations Coulomb excitation of neutron-rich Zn isotopes 80 Zn (N=50)

17. K.U. Leuven Proton Number Neutron Number Zn N=50 isotones B(E2,2 + 1  0 + 1 ) [W.u.] E(2 + 1 ) [keV] B(E2,2 + 1  0 + 1 ) [W.u.] E(2 + 1 ) [keV] Zn isotopes Shell Model (1) 56 Ni core : M. H. Jensen + monopole adjusted by Nowacki (e ,e  =(1.9e,0.9e) - (N. Smirnova et al, 2006) Coulomb excitation of neutron-rich Zn isotopes

18. K.U. Leuven  68,m Cu (2.83 MeV/u) @ 120 Sn (2.3 mg/cm 2 ) No Doppler Corr. 85 1+1+ (2 + ) 6 - 4-4- (3 - ) 722 (5 - ) 0 956 178 (M1) 693 84 778 E2 Coulomb excitation of odd-odd 68,70 Cu isomers Coulomb excitation of neutron-rich Cu isotopes and isomers e  = 1.5, e = 0.5 Note: detection of low-energy gamma rays Isomeric beams (transfer, Coulex) “Safe” multiple Coulomb excitation Extension to heavier masses Higher precision transition matrix elements I. Stefanescu,- PRL 98 (2007) 122701 J. Van de Walle,- PRL (2007) to be published

19. K.U. Leuven 1-Enhancement of fusion? Trotta et al., PRL 84 (2000), 2342 Fusion-fission experiment at Louvain-la-Neuve: mostly transfer! R. Raabe et al., Nature 431 (2004), 823 General problem:reaction mechanism of weakly bound nuclei at energies around the potential barrier Other measurements in LLN, Ganil, RIKEN, Notre Dame… with different methods and targets Importance of direct channels Reactions with Halo Nuclei Fusion reactions with unstable nuclei (LLN-RIB) E ~ 2-5 MeV/u More precise measurements Exclusive measurements (see also SPIRAL, HRIBF, ISOLDE)

20. K.U. Leuven p 3/2 p 1/2 f 7/2 f 5/2 47 Ar d p pp 28 f 7/2 p 3/2 p 1/2 f 5/2 (2J+1)C 2 S=1.7 (2J+1)C 2 S=2.44 (2J+1)C 2 S=1.36 C 2 S f =0.64 C 2 Sg=0.34 p f f p L. Gaudefroy,- PRL97 (2006) 092501 Evolution of Shells (d,p) transfer reactions using 46 Ar (SPIRAL-GANIL) 46 Ar: 2 10 4 pps, 10.2 MeV/u E ~ 5-10 MeV/u (see also HRIBF, ISOLDE)

21. K.U. Leuven d 3/2  s 1/2 1.33 0.66 f 5/2 f 7/2 Tensor interaction (T. Otsuka,- PRL95 (2005) 232502 )  d 3/2 – ( f 7/2 -f 5/2 ) +280keV per proton added in d 3/2 -210keV - 10 - 6 - 2 0 - 8 - 4 f 7/2 p 3/2 p 1/2 f 5/2 28 49 Ca 47 Ar SPE(MeV) 20 18 Variation of single particle energies (SPE) Influence of the occupancy of the  d /32 on the f 5/2 and f 7/2 orbitals Reduction of the Spin-Orbit Splittings at the N=28 Shell Closure

22. K.U. Leuven 48 Ca (>10 12 pps)  44 S (100-150 pps)  42 Si* (8/day)  42 Si +  40 Si OUT 42 Si EE M/Q SPEG (  ~100%) 44 S  42 Si E~45A.MeV 185 mg/cm² Be target BaF2 array Secondary beams SISSI 44 S IN EE TOF 48 Ca  44 S Shapes and Shells In-beam spectroscopy of fragments: 42 Si (In-Flight GANIL) B. Bastin,- PRL99 (2007) 022503 2 +  0 + : 770 ± 19 keV E ~ 50-150 MeV/u (see also GSI, MSU)

23. K.U. Leuven Future Physics with Future Physics with physics questions The physics questions are well defined interdisciplinary field wide spectrum of opportunities ISOL based RIB physics is a very broad interdisciplinary field with a wide spectrum of opportunities (has not one physics goal) physics cases beyond the original “expectations”The interesting physics cases defined at present will evolve and the instrumentation will be used beyond the original “expectations” Complementary Complementary to In-Flight RIB research conclusive answers new questionssurprise! Experience with present day RIB experiments  conclusive answers will be given and new questions will appear – surprise! A final observation target-ion sourcegroupsphysicists A strong link between target-ion source groups and the physicists is absolutely essential as the strength of the current ISOL systems is to a certain extend based on a strong involvement in the beam developments of the physicists that are using the beams. theory A strong link with and support for theory is essential

24. K.U. Leuven EMIS XIV 130 participants courtesy Mark Huyse

25. K.U. Leuven EMIS XV 195 participants: change of the guards!

26. K.U. Leuven