Overview of Recent Highlights from ISOL Facilities Juha Äystö Department of Physics, University of Jyväskylä & Helsinki Institute of Physics Finland Introduction to ISOL and Physics Low-energy and stopped beam experiments Masses, charge radii, exotic decays Post-accelerated ISOL beams Coulex and fusion Conclusions I am thankful to many colleagues, in particular to C. Gross, P. Butler, G. Bollen, J.-M- Poutissou and P. Van Duppen

driver accelerator thin targethigh-temperature thick target fragment separator experiment ion source mass separator storage ring cooling In FlightISOL heavy ions light ions, neutrons post accelerator GeV/u (  s) meV to 100 MeV/u (ms to several s) gas catcher (ms) IGISOL (ms) Cooling & trapping Charge breeding experiment RILIS NEW !!!

SHIPTRAP GSI ISOLDE CERN SPIRAL GANIL ISOL-JAERI ISAC TRIUMF HRIBF Oak Ridge ANL LEBIT-MSU SLOWRI RIKEN IGISOL Jyväskylä + IGISOLs at Sendai and Warsaw EXCYT Catania LISOL Leuven Thick target ISOL IGISOL / gas catcher

ISOL RIB Physics Reach

A major question: SHELL STRUCTURE FAR FROM STABILITY ? IMPACT ON R-PROCESS ? Spin-orbit ? Pairing ? Effective force ? -tensor force Continuum-coupling?…… Spin-orbit ? Pairing ? Effective force ? -tensor force Continuum-coupling?…… B. Pfeiffer et al. Acta Phys. Polon. B27(1996) ?

J.Dobaczewski and W.Nazarewicz Phil. Trans. R. Soc. Lond. A356, 2007 (1998) J.Dobaczewski and W.Nazarewicz Phil. Trans. R. Soc. Lond. A356, 2007 (1998) Shell gap energy and magicity ? – HFB + SkP calculation 100 Sn 78 Ni 132 Sn 48 Ca 208 Pb NEW ISOL-DATA !!!

SPEG TOFI HALF-LIFE RANGE [s] A C C U R A C Y  m / m Direct Mass Measurement Techniques Penning traps ESR-TOF ESR Schottky D. Lunney, et al., Rev. Mod. Ph. 75(2003)1021

 M/M <  M/M < B Penning trap STEPS of measurement: * cooling and bunching in buffer gas filled RFQ (ms) * mass selective cooling & purification in preparation Penning trap (> 10 ms); R=10 5 * mass measurement or isomer separation in precision Penning trap (100 ms); R=10 6 For details: See A. Jokinen (A1-4), S. George (F9-4), P. Schury (H2-6), J. Dilling (J2-1), A. Herlert (QW-071), A. Jokinen (QT227)

PERFORMANCE: R = 10 7 → δm/m ≥ 8  PERFORMANCE: R = 10 7 → δm/m ≥ 8  m Bunches, 3keV energy 60keV ISOLDE- ion beam 1 c m 5 c m V B = 4.7 T B = 6 T Linear RFQ trap ISOLTRAP 1 cm  100 MeV/u  1 eV Penning trap mass measurements Laser spectroscopy soon Gas stopping Beam preparation LEBIT JYFLTRAP [18] G. Bollen, D. Davies, M. Facina, et al., Phys. Rev. Lett. 96, (2006). A. Herlert, et al., Int. J. Mass Spectrom. 251, (2006) 131 T. Eronen, et al., Phys. Rev. Lett. 97, (2006)  M/M <  M/M < B Penning trap CERN Jyväskylä NSCL-MSU

Highlights of nuclear mass measurements at ISOL facilities MSU: 38 Ca, 70m Br, 68 Se 44 S, n-rich 65 Fe and 66 Co MSU: 38 Ca, 70m Br, 68 Se 44 S, n-rich 65 Fe and 66 Co Argonne: 46 V, 64 Ge heavy fission products Argonne: 46 V, 64 Ge heavy fission products CERN: ~300 isotopes measured 22 Mg, 32 Ar, 72 Kr 74 Rb, 81 Zn, 133 Sn CERN: ~300 isotopes measured 22 Mg, 32 Ar, 72 Kr 74 Rb, 81 Zn, 133 Sn GSI: masses of rp nuclei drip-line nuclei GSI: masses of rp nuclei drip-line nuclei Jyväskylä: ~200 isotopes measured 26 Si, 62 Ga, 92 Rh fission products; 83 Ga, 110 Mo Jyväskylä: ~200 isotopes measured 26 Si, 62 Ga, 92 Rh fission products; 83 Ga, 110 Mo

92 Br: S n =3.2 MeV JYFLTRAP ISOLTRAP at CERN STABLE 100 Sn 132 Sn 78 Ni 189 NEW MASSES Niobium ? New mass measurements of fission products T 1/2 ≈ 100 ms

Zr 78 Ni EVOLUTION OF N=50 SHELL GAP Next critical mass: 82 Zn !! ISOLTRAP ???

Isotopes measured by laser spectroscopy -H.-J. Kluge and W. NörtershäuserSpectrochim. Acta B 58,(2003) 1031 Measured at IGISOL - cooled and bunched ion beams - refractory element 11 Li (8.5 ms); ISAC *, 6 He; ANL n-rich yttrium isotopes; IGISOL * multi-qp isomers; IGISOL 130m Ba (10 ms), 178m1 Hf… n-rich Be; RIKEN 31 Mg HFS+  NMR; ISOLDE Highlights of laser spectroscopy at ISOL facilities Next 8 He at GANIL ?

2s 2 S 1/2 3s 2 S 1/2 2p 2 P 1/2,3/2 3d 2 D 3/2,5/2  = 30 ns 735 nm 610 nm 5.4 eV Lithium atomic levels Resonance Ionization of 11 Li 735 nm Atoms/s Technique developed at GSI Atoms/s Technique developed at GSI.

R. Sánchez et al., PRL 96, (2006) Nature Physics 2, 145 (2006) M. Puchalski et al., PRL 97, (2006) R. Sánchez et al., PRL 96, (2006) Nature Physics 2, 145 (2006) M. Puchalski et al., PRL 97, (2006) Results: Nuclear Charge Radii I. Tanihata et. al. PRL 55, 2676 (1985) I. Tanihata et. al. PL B 206, 592 (1988) This surprising result indicates that the Li-core is indeed strongly perturbed or polarized by interactions between halo neutrons and core nucleons.

+40 kV Ion beam cooler Light collection region (Laser resonance fluorescence) Traps and accumulates ions – typically ms Reduces energy spread of ion beam (< 1eV) Improves emittance of ion beam Releases ions in a 10 µs bunch Beam cooling and bunching with RFQ A. Nieminen, et al., Nucl. Instr. Meth. B 204 (2003) 563 Beam cooling and bunching with RFQ A. Nieminen, et al., Nucl. Instr. Meth. B 204 (2003) 563 2∙10 4 improvement of SNR ! Allows to work with 100 ions/s rates 174 Hf

Yttrium charge radii Yttrium charge radii B. Cheal et al., Phys. Lett. B 645, (2007). Increased binding due to large prolate deformation! Result very similar to neighboring Sr and Zr chains Shape coexistence!

Highlights of decay studies at ISOL facilities ISOLDE & IGISOL: Triple-  structure of 12 C 12 N & 12 B  3  decay ISOLDE & IGISOL: Triple-  structure of 12 C 12 N & 12 B  3  decay ISOL at GSI: * 2 He decay of 94m Ag ISOL at GSI: * 2 He decay of 94m Ag Jyväskylä: Trap-assisted spectroscopy 104 Zr, 113 Tc,… Jyväskylä: Trap-assisted spectroscopy 104 Zr, 113 Tc,… HRIBF at Oak Ridge: Ranging out spectroscopy 79 Cu, 85 Ga,… HRIBF at Oak Ridge: Ranging out spectroscopy 79 Cu, 85 Ga,… Several facilities: * Superallowed  -decays 22 Mg, 26 Al,… 62 Ga, 74 Rb Several facilities: * Superallowed  -decays 22 Mg, 26 Al,… 62 Ga, 74 Rb LISOL at Leuven: RILIS in decay studies 67m Co,… LISOL at Leuven: RILIS in decay studies 67m Co,… JAERI: Heavy fission products JAERI: Heavy fission products ISOLDE: 132 Sn-region spectroscopy ISOLDE: 132 Sn-region spectroscopy

10 C 14 O 26m Al 38m K 42 Sc 46 V 50 Mn 54 Co 34 Cl Ft = ± 0.8 s V ud = (4) From Ft and G A of muon decay J.C Hardy and I.S. Towner, Phys. Rev. C 71(2005) )1(2 ) )(1( 2V RV C R G K ftFt      ’ 1+  NS New Q-value determinations with Penning Traps 22 MgM. Mukherjee et al., Phys. Rev. Lett. 93 (2004) Al m, 42 Sc, 46 VT. Eronen et al., Phys. Rev. Lett. 97 (2006) Ar F. Herfurth et al., Eur. Phys. J. A 15 (2002) CaG. Bollen et al., Phys. Rev. Lett. 96 (2006) VG. Savard et al,, Phys. Rev. Lett. 95 (2005) GaT. Eronen et al., Phys. Lett. B 636 (2006) RbA. Kellerbauer et al., Phys. Rev. Lett. 93 (2004) Alarming new result of Q EC of 46 V from CPT and JYLFTRAP:  (Q EC )=2.2 (9) keV ? --> Need to check all Q EC values ! Unitarity of CKM matrix?  = (14) !! Unitarity of CKM matrix?  = (14) !! CVC and the unitarity of the CKM matrix !

New data (ISOLDE, ISAC, IGISOL, CPT) New yet unpublished measurements 26 Al, 26 Si, 42 Ti, 50 Mn, 54 C0

Current Status – CKM Matrix Unitarity check via the matrix elements of the first row: V us and V ub from particle physics data (K and B meson decays) Most precise V ud From nuclear β decay ! 4th Int. Workshop on the CKM Unitarity Triangle, Nagoya, 12/2006 M. Moulson, ArXiV:hep-ph/ J. C. Hardy, ArXiV:hep-ph/ v1 V ud = (27) Confirms the unitarity, but more work needed on theoretical corrections as well as new data!

Post-accelerated ISOL FACILITYDRIVERPOWERUSER BEAMS ACCELERATED ENERGYPHYSICS REACH LOUVAINE- LA-NEUVE (BELGIUM) MeV protons 6 kW 6 He, 7 Be, 10,11 C, 13 N, 15 O, 18 F, 18,19 Ne, 35 Ar 10 MeV/u cyclotron Astrophysics, Nuclear structure HRIBF Oak Ridge (USA) MeV p, d,  (-ve ion source) 1 kW 7 Be, 17,18 F, 69 As, 67,83 Ga, Cu, Ge, 84 Se, 92 Sr, 118,120,122,124 Ag, 129 Sb, Sn, 132,134,136 Te MeV/u tandem Nuclear Structure, Astrophysics ISAC TRIUMF (CANADA) MeV protons 50 kW 8,9,11 Li, 11 C, 20,21 Na, 18 Ne, 26 Al, 34 Ar 4.5 MeV/u linac Astrophysics, Condensed matter, Nuclear Structure SPIRAL GANIL (FRANCE) MeV/u heavy ions 6 kW 6,8 He, 15,19-21 O, 18 F, 17-19,23-26 Ne, 33-35, 44,46 Ar, Kr MeV/u cyclotron Nuclear structure, Astrophysics REX ISOLDE (CERN) GeV protons 3 kW 8,9 Li, 10,11 Be, Na, Mg, 68 Ni, Cu, 74,76,78,80 Zn, 70 Se, 88,92 Kr, 108 In, 108,110 Sn, 122,124,126 Cd, 138,140,142,144 Xe, 148 Pm, 153 Sm, 156 Eu MeV/u linac Nuclear structure, Condensed matter, Astrophysics

counts energy (keV) 78 Zn 80 Zn 108 Pd 730 keV: keV: Ga 78 Ga 108 Pd x Zn (T 1/2 = Pd (2.0 mg/cm 2 ) Energy = 2.79 MeV/u Intensity = 3000 pps Purity = 43 (5) % 78 Zn (T 1/2 = Pd (2.0 mg/cm 2 ) Energy = 2.87 MeV/u Intensity = 4300 pps Purity = 64 (13) %  Coulomb excitation of even- even Zn isotopes up to N=50 * laser on laser off * J. Van de Walle et al., to be published

Proton Number Neutron Number Ni Zn Ge N=50 isotones B(E2,2 + 1  ) [W.u.] E(2 + 1 ) [keV] B(E2,2 + 1  ) [W.u.] E(2 + 1 ) [keV] Ni,Zn,Ge isotopes this work Ge up to N=50: HRIBF exp: Phys. Rev. Lett. 94(2005) Result in conformity with the new mass data !

Enhancement of 9 Li sub-barrier fusion W. Loveland et al, Physical Review C 74(2006) ISAC I at TRIUMF

Shapira et al., Eur. Phys. J. A 25, s01, 241 (2005) Liang et al., PRL 91, (2003); PRC 75, (2007) Fusion with heavy n-rich radioactive beams Large sub-barrier fusion enhancement Inelastic excitation and neutron transfer play an important role in the observed fusion enhancement Important for superheavy element synthesis ERs made with 132,134 Sn cannot be made with stable Sn!

Fusion with n-deficient radioactive beams 76 Kr + 58 Ni 130 Nd (4p) 131 Pm (3p) 129 Pr (5p) SPIRAL(GANIL)

Conclusions Traditional ISOL method is succesfully complemented by IGISOL and gas catcher techniques –gaining universality in RIB production Novel ion manipulation techniques (RFQ, charge breeding, ion traps,…) have made significant impact towards high-sensitivity and precision experiments Penning trap technique coupled with an ISOL method opens new opportunities for mass and spectroscopy measurements –About 500 atomic masses measured with precision better than 10 keV –Mass derivatives can probe nuclear structure (deformation, shell gaps) –Evidence observed for the persistence of the neutron shell gap towards 78 Ni Post-accelerated RIBs start producing physics on n-rich nuclei –Coulex and transfer reaction experiments shown feasible –Isomeric beam production demonstrated –Role of ”magic” numbers far from stability Results on N=20, 50 and 82 n-rich nuclei ISOL & future: Intensity and precision frontier !

Shell Gap Energies from Theory M. Stoitsov, et al, Phys. Rev. Lett. 98, (2007) HFB-THO + density functional theory J. Pearson, S. Goriely Nuclear Physics A 777(2006)623 P. Möller et al. ADNDT 59(1995)185 Fit to 2149 measured masses (AME03)