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The DESIR facility at SPIRAL2

The DESIR facility at SPIRAL2. DESIR: Désintégration, excitation et stockage d’ions radioactifs (Decay, excitation and storage of radioactive ions) Result of a SPIRAL2 workshop in July 2005 on ISOL beams at SPIRAL2: - Decay spectroscopy: Maria José Garcià Borge (Madrid)

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The DESIR facility at SPIRAL2

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  1. The DESIR facility at SPIRAL2 • DESIR: Désintégration, excitation et stockage d’ions radioactifs • (Decay, excitation and storage of radioactive ions) • Result of a SPIRAL2 workshop in July 2005 on ISOL beams at SPIRAL2: • - Decay spectroscopy: Maria José Garcià Borge (Madrid) • - LASER spectroscopy: François Le Blanc (IPN Orsay) • Gerda Neyens (KU Leuven) • Paul Campbell (Manchester) • - Atom and ion traps:Dave Lunney (CSNSM) • Oscar Naviliat-Cuncic (LPC Caen • Frank Herfurth (GSI) • Spokes-person: Bertram Blank • GANIL liaison: Jean-Charles Thomas Bertram Blank, SAC SPIRAL2, 19-20 October 2006

  2. pps pps A pps A Why another ISOL facility? • close to stable beam intensities for exotic nuclei • much higher intensities than at ISOLDE or Oak Ridge • not too far from EURISOL intensities • key nuclei like 78Ni, 100Sn, 132Sn with high intensities • fusion-evaporation to access high-spin states

  3. Conclusions of the SPIRAL2 Workshop (july 2005): Low energy RIB 1.A new experimental area of about 1500m2 located at the ground floor, dedicated to the experiments with low-energy beams from SPIRAL2 is strongly requested. The new building includes areas for the experimental equipments, acquisition and control rooms. 2. A High Resolution mass Separator (HRS) with a resolution of M/M>5000with a dedicated identification stationis absolutely necessary. A separation scheme Low Resolution mass separator → RFQ cooler → HRS is proposed. 3. The low energy radioactive beams should be available for experiments already at the beginning of the operation of SPIRAL 2. The physics program requires both neutron-rich and neutron-deficient beams. 4.More than one production target – ion source station is required to ensure flexible schedule and a possibility for fast change of the mass of radioactive beams. 5.An extension of the current LIRAT beam line in order to takefull advantage of the SPIRAL 1 beams is proposed.

  4. DESIRphysics program • Decay spectroscopy - decay properties and nuclear structure studies - particle-particle correlations, cluster emission, GT strength - exotic shapes, halo nuclei • Laser spectroscopy - static properties of nuclei in their ground and isomeric states - deformation • Fundamental interactions - CVC hypothesis, CKM matrix unitarity via 0+ 0+ transitions - exotic interactions (scalar and tensor currents) - CP (or T) violation with e.g. Radium • Solid state physics and other applications

  5. SPIRAL 2 LAYOUT Production building DESIR LINAG GANIL facility LIRAT

  6. Underground J.C. Thomas, GANIL

  7. DESIR: Ground-floor LUMIERE general purpose spec Paul trap laser MOT trap BESTIOL neutrons buncher Ion sources x

  8. Beam handling: methods Magnetic separation (HRS) PENNING TRAP A. Jokinen, JYFL

  9. RF Beam handling: RFQ cooler and buncher RFQ-cooler: 3 p mm mrad, 0.5 eV, 10 ms, 60 % D. Lunney et al., CSNSM

  10. Beam handling: Implementation F. Varenne, GANIL

  11. Summary of decay spectroscopy experiments: The BESTIOL facility (BEta decay STudies at the SPIRAL2 IsOL facility) • Decay studies with halo nuclei • Clustering studies in light nuclei • Super-allowed b decays and the standard model of electro-weak interaction • Angular correlation measurements and standard model of electro-weak interaction • Cases of astrophysical interest • New magic numbers • Transition from Order to Chaos • Shape coexistence, deformation and Gamow-Teller distribution • High-spin isomers • Test of isospin symmetry combined with charge exchange reactions • Beta-delayed charged-particle emission: e.g. proton-proton correlation

  12. Short half-lives (10ms) • High Qb values • Low Sp/n values • Selection rules: • Fermi: DT=0 ;DJ=0 ; pf = pi • Gamow-Teller: DT=0±1; DJ=0±1; pf = pi • Reduced transition probability: Decay properties of exotic nuclei • 1916 Rutherford & Wood [Philos. Mag. 31 (1916) 379] • 1963Barton & Bell identified 25Si as p emitter • Global properties -delayedparticle emission • Very Selective probe E,  Level density Spin, Isospin -decay properties

  13. Search for exotic interactions e+ nucleus q ne • b-n angular correlation requires to measure the recoil ion + b particle • within the SM x : Fermi fraction; r : GT/F mixing ratio • beyond the SM a contains quadratic S and T contributions O. Naviliat-Cuncic et al., LPC Caen

  14. Search for exotic interactions: Production and preparation of 6He candidate: (pure GT transition) deduce bn angular correlation from measurement of b-recoil (recoil with very low energies < 1 keV) 6He+ production at SPIRAL cooling in H2 gas / bunching trapping/measuring LIRAT low energy beam line O. Naviliat-Cuncic et al., LPC Caen

  15. beta telescope PM plastic scintillator DSSSD beam monitor mCP 6He+ 10cm mCP recoil ion detector Search for exotic interactions: Setup and first results • TOF of ions extracted from trap • first time difference for b-decay RF ON/OFF (V-A theory) O. Naviliat-Cuncic et al., LPC Caen

  16. CVC, CKM, exotic currents: 0+  0+ b decays = 3073.5 (12) s(1) 3074.4 (12) s (1,2) Measurements: - Q value - T1/2 - branching ratios  Vud0+0+ = 0.9738(4)(1) 0.9736(3)(1,2,3) VusK= 0.2200(23)(PDG) 0.2254(21)(4) VubB = 0.00367(47)(PDG)  0.9987(11) (~ 2 shift) (1) Towner and Hardy, PRL 94 (2003) 092501, PRC 71 (2005) 055501 (2)Savard et al., PRL 95 (2005) 102501 (3)Marciano & Sirlin, PRL 96 (2006) 032002 (4) E865, KTeV, NA48, KLOE (PDG) Particle Data Group, S. Eidelman et al., PLB 592 (2004) 1

  17. 0+  0+ b decays: Physics output • 1. Vudmatrix element ( test of unitarity) • 2. test of CVC (constancy of Ft0+ 0+ values) • 3. right-handed currents: • -0.0005 <  < 0.0015(90% C.L.) • 4. scalar currents: Ad 3: Left Right Symm.-models W1 = WL cos - WR sin W2 = WL sin + WR cos  = m12 / m22 0.011 Ad 4: scalar currents N. Severijns et al.

  18. 0+  0+ b decays: Future studies • further improve results for “classical” isotopes • determine Ft-values for new isotopes of interest: • Tz= -1 isotopes: 18Ne, 22Mg, 26Si, 30S, 34Ar, 38Ca,42Ti • Tz=0 isotopes: 62Ga, 66As, 70Br, 74Rb, 78Y, 82Nb, 86Tc, 90Rh, 94Ag,98In • stronger limits for new physics • test and improve reliability of isospin corrections • extend CVC test to higher mass region •  needs: • -relatively pure beams ( 103 at/s) of ‘classical’ and new 0+ 0+ isotopes • - precision spectroscopy techniques (for t1/2 and BR) • - Penning traps (mainly for QEC/mass)

  19. Experiment Theory Counts Energy (keV) Study of GT strength via b-delayed proton decay: 21Mg 21Mg J.C. Thomas

  20. b+ : p→n + e+ +  d = 4.8 (4) % b- : n→p + e- +  E.C. : p + e-→n +  ft- ft+ n p n p Mirror symmetry studies  = nuc + SCC • Allowed Gamow-Teller transitions (log(ft)<6) • 17 couples of nuclei • 46 mirror transitions Average asymmetry d : 11 (1) % in the 1p shell (A<17) 0 (1) % in the (2s,1d) shell (17<A<40) J.C. Thomas, J. Giovinazzo et al. (GANIL/CENBG)

  21. Search for p-p correlation in b2p decay • Two possible decay schemes: • sequential → no angular or energy correlation • 2He type decay → angular and energy correlation •  pairing correlations, nucleon-nucleon interaction, final-state interactions…. Possible candidates: 22Al, 23Si, 26P, 27S, 31Ar, 35Ca, 43Cr, 50Ni …. • Setup: Cube-silicium • 6 DSSSD • 6 large-area • silicon det. • g detection • beam catcher • or fast tape I. Matea et al., CEN Bordeaux-Gradignan

  22. Study of decay of 31Ar at SPIRAL/LIRAT Proton spectrum • Production rate: 0.5 – 1 31Ar per second • strong contamination from 33Ar I. Matea et al., CEN Bordeaux-Gradignan

  23. One- and two-proton emission from isomers: 94Ag

  24. Seq One- and two-proton emission from isomers: 94Ag Relative energy spectra for p-p 3-body 0.39(4)s 1.9 keV Si-Si- (92Rh) I. Muhka, Nature 439 (2006) 298

  25. } for ground and isomeric states LUMIERE: Laser Utilisation for Measurement and Ionization of Exotic Radioactive Elements • Collinear Laser spectroscopy: • - spins • - magnetic moments • - quadrupole moments • - change of charge radii • N=50, N=64, N=82, etc. • b-NMR spectroscopy: • - nuclear gyromagnetic factor • - quadrupole moment • monopole migration of proton and neutron single particle levels around 78Ni • persistance of N=50 shell gap around 78Ni • persistance of N=82 shell gap beyond 132Sn • Microwave double resonance in a Paul trap: • - hyperfine anomaly and higher order momenta • (octupole and hexadecapole deformation) • Eu, Cs, Au, Rn, Fr, Ra, Am ….

  26. Atomic hyperfine structure Interaction between an orbital e- (J) and the atomic nucleus (I,mI,QS) • results in a hyperfine splitting (HFS) of the e- energy levels n J with F DEHFS • Hyperfine structure constants: and • Collinear laser spectroscopy: DmI/mI ~ 10-2, DQS/QS ~ 10-1 for heavy elements

  27. Isotope shift measurements Frequency shift between atomic transitions in different isotopes of the same chemical element • related to the mass and size differences J2, F2 dnA,A’ J2, F2 J1, F1 J1, F1 • mean square charge radius variations with a precision ~ 10-3 • study of nuclei shape (deformation)

  28. Isotope shift and nuclear moment measurements 178Hf isomer at Orsay F. Le Blanc et al. 101Zr at JYFL P. Campbell et al.

  29. COMPLIS • onset of deformation at N=82 (slope ↔ rigidity) • shape transition (even-odd staggering) • shape coexistence • dynamical effects (vibration) Isotope shift measurements • previous experiments: N~82 N~104 F. Le Blanc et al., IPN Orsay

  30. Isotope shift measurements at DESIR • with I ~ 103-104 pps: • N~50: • neutron skin in N > 50 Ge isotopes (neutron star studies) • deformation in N ≤ 50 Ni isotopes (collectivity vs magicity) • N~82: • shape evolution for Z ≤ 50 (Ag, Cd, In, Sn) • N~64: • strongly oblate shapes predicted in Rb, Sr and Y for N > 64 • Z~40: • shape transitions predicted in the Zr region (Mo, Tc, Ru) • Rare earth elements: • large deformation and shape transitions predicted (Ba, Nd, Sm)

  31. B0 b-NMR spectroscopy b-asymmetry in the decay of polarized nuclei in a magnetic field • Zeeman splitting related to gI and QS M+I I M-I with and • resonant destruction of the polarization (i.e. b-asymmetry) by means of an additional RF magnetic field • DgI/gI ~ 10-3, DQS/QS ~ 10-2 • complementary technique to collinear laser spectroscopy • suitable for light elements(low QS values)

  32. The physics case for b-NMR on polarized 60 keV beams • polarized 60 keV beams are obtained using resonant laser excitation. • with I ≥ 5.103 pps, T½ from 1 ms to 10 s, beam purity > 50 %. • b-NMR is a sensitive and precise method to measure g-factors and quadrupole moments of exotic nuclei (ground states, isomers) with lifetimes from 1 ms up to several seconds. • combination with hyperfine structure measurements yields a unique determination of the spin (e.g. PRL 94, 022501 (2005)). • Systematic precise measurements of g-factors reveal deviations from ‘normal’ behaviourand provide information on configuration mixing or onset of deformation (breaking of shell closures). • N~50: g factor of neutron-rich Ga and Cu isotopes to determine where the inversion of the pp3/2 and pf5/2 orbitals occurs. • N~82: g.s. configuration from gI measurements.

  33. Z=40 Z=28 N=50 N=40 The physics case for b-NMR on polarized beams: nuclear structure towards and beyond 78Ni Kr Produced at SPIRALII with d-induced fission Se Ge • Evolution of n orbits • from Z=40 to Z=28: • ground state spins and moments • of 83Ge, 81Zn, 79Ni and • of 81Ge, 79Zn, 77Ni • g-factors can reveal erosion of N=50 shell closure Zn Ni Lifetime OK for b-NMR studies G. Neyens et al., KU Leuven

  34. Collinear laser spectroscopy and b-NMR • previous experiments at COLLAPS: • from the position of hyperfine transitions: spin assignment and sign of gI for the g.s. of 31Mg HFS 31Mg1+ basymmetry nRF (MHz) • from b-NMR: precise measurement of |gI| • strongly deformed intruder Ip = 1/2+ g.s. of 31Mg, G. Neyens et al, PRL 94, 022501 (2005) • from QS measurements via b-NMR: QS(11Li) > QS(9Li)  p-n interaction + halo n orbitals, D. Borremans, Ph.D. Thesis, 2004, KU Leuven R. Neugart et al.

  35. Estimated budget • Building: 6000 kEuros • - DESIR hall: 3000 kEuros • - Basement: 1000 kEuros • - Crane: 1000 kEuros • - 20 % overhead: 1000 kEuros • HRS: 816 kEuros • - RFQ cooler: 150 kEuros • - 2 magnets + power supplies: 400 kEuros • - pumps, beam lines, diagonstics: 130 kEuros • - 20% overhead: 136 kEuros • Beam handling: 1640 kEuros • - off-line source: 60 kEuros • - RFQ cooler/buncher and switch yards: 650 kEuros • - Preparation Penning trap: 460 kEuros • - in-trap decay detection system: 195 kEuros • - 20% overhead: 275 kEuros • Lumière: 972 kEuros • - Laser room with infrastructure 150 kEuros - Two lasers (dye + Ar) 180 kEuros - Collinear laser spectroscopy: 170 kEuros - ß-NMR set-up: 160 kEuros - Paul trap set-up: 150 kEuros • - 20% overhead: 162 kEuros • Decay spectroscopy: 2160 kEuros • - Four Germanium detectors: 1225 kEuros • - Fast timing set-up: 34 kEuros • - 4p charged particle array: 168 kEuros • - Neutron detection array: 400 kEuros • - 20% overhead: 333 kEuros • Fundamental interactions: 600 kEuros • - MOT trap: 350 kEuros • - in-flight decay setup: 150 kEuros • - 20% overhead: 100 kEuros • Beam lines: 3600 kEuros • ------------------------------------------------------------------------------------------------------------------------------------------------ • TOTAL: 15788 kEuros

  36. Lynda Achouri, LPC Caen Alejandro Algora, IFIC Valencia Jean-Claude Angélique, LPC Caen Alain Astier, CSNSM Orsay Georges Audi, CSNSM Orsay Juha Aysto, University of Jyvaskyla Dimiter Balabanski, INRNE Sofia Emmanuel Balanzat, CIRIL Caen Gilles Ban, LPC Caen Bertram Blank, CENBG Bordeaux Klaus Blaum, University Mainz Maria Jose Garcia Borge, CSIC Madrid Dorel Bucurescu, NIPNE Bucarest Apostol Buta, NIPNE Bucarest Paul Campbell, University Manchester Grégory Canchel, CENBG Bordeaux Daniel Cano Ott, CIEMAT Madrid Joakim Cederkall, ISOLDE-CERN Fatima Dayras, CSNSM Orsay Giacomo de Angelis, INFN Legnaro Pierre Delahaye, ISOLDE-CERN Jean-Pierre Delaroche, CEA Bruyères Frank Delaunay, LPC Caen Isabelle Deloncle, CSNSM Orsay François de Oliveira Santos, GANIL Caen Philippe Dessagne, IPHC Strasbourg Gilbert Dûchene, IPHC Strasburg Cédric Dossat, DAPNIA Saclay Dominique Durand, LPC Caen Serge Franchoo, IPN Orsay Xavier Fléchard, LPC Caen Kieran Flanagan, University Leuven Carole Gaulard, CSNSM Orsay Bill Gelletly, University of Surrey Georgi Georgiev, CSNSM Orsay Omar Gianfrancesco, CSNSM Orsay Jérôme Giovinazzo, CENBG Bordeaux Stéphane Grévy, GANIL Caen Héloise Goutte, CEA Bruyères-le-Chatel Paul-Henri Heenen, University Brussels Frank Herfurth, GSI Darmstadt Jussi Huikari, CENBG Bordeaux Fadi Ibrahim, IPN Orsay Ari Jokinen, University Jyväskylä Andrea Jungclaus, University Madrid Klaus Jungmann, KVI Gronningen Swaminathan Kailas, BARC Mumbai Jürgen Kluge, GSI Darmstadt Magdalena Kowalska, University Mainz François Le Blanc, IPN Orsay Roy Lemmon, CCLRC Daresbury Marek Lewitowicz, GANIL Caen Etienne Liénard, LPC Caen David Lunney, CSNSM Orsay Miguel Marques, LPC Caen Ismael Martel, Universidad de Huelva Iolanda Matea, CENBG Bordeaux Enrique Minaya-Ramirez, CSNSM Orsay Iain Moore, University of Jyväskylä Oscar Naviliat-Cunic, LPC Caen Florin Negoita, NIPNE Bucarest Gerda Neyens, University Leuven C.J.G. Onderwater, KVI Groningen Nigel Orr, LPC Caen Dan Pantelica, NIPNE Bucarest Sophie Péru-Desenfants, CEA Bruyères Stephane Pietri, University of Surrey Natalie Pillet, CEA Bruyères-le-Chatel Natalie Pillet, CEA Bruyères-le-Chatel Zsolt Podolyak, University of Surrey Marie-Genevieve Porquet, CSNSM Orsay Wolfgang Quint, GSI Darmstadt Paul-Gerhard Reinhard, University of Erlangen Ernst Roeckl, GSI Darmstadt Daniel Rodriguez, Universidad de Huelva Brian Roeder, LPC Caen Bertra Rubio, University Valencia Lutz Schweikhard, University Greifswald Nathal Severijns, University Leuven Aradhana Shrivastava, BARC Mumbai Cosimo Signorini, INFN Padova Gary Simpson, LPSC Grenoble John Simpson, CCLRC Daresbury Olivier Sorlin, GANIL Caen Krunoslav Subotic, University Belgrade Olof Tengblad, CSIC Madrid Catherine Thibault, CSNSM Orsay Jean-Charles Thomas, GANIL Caen Dragan Toprek, University Belgrade Piet van Duppen, University Leuven David Verney, IPN Orsay Phil Walker, University Surrey Christine Weber, GSI Darmstadt L. Willmann, KVI Gronningen Hans Wilschut, KVI Gronningen Martin Winkler, GSI Darmstadt Nicolae Victor Zamfir, NIPNE Bucarest The DESIR Collaboration

  37. Summary • solid physics case • very promising intensities for exotic nuclei (e.g. fusion-evaporation) • almost 100 co-authors the « DESIR » LOI • with its installations a unique facility • preliminary study of building at CENBG • study of cooler/buncher and HRS at CSNSM • installation of collinear laser spectroscopy at ALTO • to be built it has to be included in « reference solution » • synergies with FAIR: DESPEC, LASPEC, MATS, NCAP

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