DESIR  SPIRAL2 organization & scientific program layout of the facility status and perspectives LUMIERE  Laser DESIR: the LUMIERE project Laser spectroscopy studies at the DESIR facility of SPIRAL2 J.C. Thomas – XV th Colloque GANIL, Giens 2006 physics cases experimental techniques research program

DESIR Désintégration, Excitation et Stockage d’Ions Radioactifs  Results from the SPIRAL2 workshop held at GANIL on July 2005 « Physics with low energy beams at SPIRAL2 » An open collaboration to promote ISOL beams at SPIRAL2  Follows the earlier proposition of a low-energy RIB facility at SPIRAL - Promotors (1998): G. Auger, B. Blank, C. Le Brun, …. - LIRAT facility (2005): 6 He, 19 Ne, 32,35 ~ 30 keV talk by A. Mery

DESIR organization  Working groups / correspondents: - Beam handling and beam preparation / - Laser spectroscopy / - Decay spectroscopy / * spokes-person: B. Blank, * GANIL correspondent: J.-C. Thomas,  Links to SPIRAL2 project management: - Scientific program: M. Lewitowitcz - Installation: M.-H. Moscatello

DESIR physics 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 - nuclear structure and deformation  Fundamental interactions - CVC hypothesis, CKM matrix unitarity via 0 +  0 + transitions - exotic interactions (scalar and tensor currents) - CP and T violation  Solid state physics and other applications

 A new experimental area of about 1500m 2  Availability from day 1  Run in parallel with post-accelerated beams Fast change of the mass setting Neutron-rich and neutron-deficient beams  More than one production station  Different target-ion source assemblies including a laser ionization source  Different production modes including fusion-evaporation and DI reactions  Use of isotopically separated beams  A high resolution mass separator with a resolution of M/  M>5000  Extension of the current LIRAT beam line The DESIR SPIRAL2 technical requirements

LINAG Production building GANIL facility LIRAT DESIR The DESIR SPIRAL2 layout

LINAG Production building DESIR HRS Ident. Station Exp. Area GANIL

GANIL facility today DESIR building - Underground

DESIR building - Ground floor Laser Spectroscopy Decay studies Other purposes Fundamental Interactions Spectroscopy of trapped beams talk by A. Herlert talk by M.J.G. Borge talks by A. Mery and N. Severijns talk by P. Delahaye this talk and P. Mueller Cooling/Bunching

Status of the DESIR Project  DESIR building (new experimental area)  High resolution separator  Beam preparation (cooler) preliminary design study: B.Blank et al., CEN Bordeaux-Gradignan preliminary design study: D. Lunney et al., CSNSM Orsay O. Naviliat et al., LPC Caen + D. Lunney et al., CSNSM Orsay LoI  LoI to be submitted in October 2006 (Contact: B. Blank)  Presentation of the DESIR Project to the IN2P3 SC in July 2006

Synergies with other facilities  ALTO: laser ionization source, laser spectroscopy  FAIR/NuSTAR: MATS, LASPEC, NCAP, DESPEC  RIKEN/RIBF: SLOWRI  Common issues beam preparation using coolers and traps low-energy beam diagnostics new types of gamma and neutron detectors

Towards DESIR: LIRAT extension  Multi-beam facility (physics program  2012)  Tests and development for SPIRAL2 & DESIR LIRAT today SPIRAL n+n+n+n+ LPC Trap Tests  Spec.  Spec.

The LUMIERE DESIR Laser Utilisation for Measurement and Ionization of Exotic Radiaoctive Elements Spokes-person: F. Le Blanc, Physics cases:  Nuclear structure and deformation studies far from stability, in the vicinity of closed shells  Hyperfine anomaly and high-order components of the hyperfine interaction  from systematic measurements of the static properties of exotic nuclei in their ground and isomeric states: ,  I, Q s, I   from precise measurements of the hyperfine structure constants  collinear laser spectroscopy +  -NMR  double laser + RF spectroscopy in traps

Atomic hyperfine structure Interaction between an orbital e - (J) and the atomic nucleus (I,  I,Q S )  results in a hyperfine splitting (HFS) of the e - energy levels J n F  E HFS with  Hyperfine structure constants: and  Collinear laser spectroscopy:   /   ~ 10 -2,  Q S /Q S ~ for heavy elements

Isotope shift measurements Frequency shift between atomic transitions in different isotopes of the same chemical element  related to the mass and size differences J1, F 1 J2, F 2 J1, F 1 J2, F 2  A,A ’  mean square charge radius variations with a precision ~  study of nuclei shape (deformation)

 previous experiments: Isotope shift measurements N~82 N~104  onset of deformation at N=82 (slope ↔ rigidity)  dynamical effects (vibration)  shape coexistence  shape transition (even-odd staggering) COMPLIS

 with I ~ pps : Isotope shift measurements at DESIR  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)

 -NMR spectroscopy  -asymmetry in the decay of polarized nuclei in a magnetic field  Zeeman splitting related to g I and Q S I M +I M -I  resonant destruction of the polarization (i.e.  -asymmetry) by means of an additional RF magnetic field withand B0B0   g I /g I ~ 10 -3,  Q S /Q S ~  complementary technique to collinear laser spectroscopy  suitable for light elements (low Q S values)

COLLAPS  previous experiments at COLLAPS: Collinear laser and  -NMR spectroscopy  from the position of hyperfine transitions: spin assignment and sign of g I for the g.s. of 31 Mg HFS 31 Mg 1+  from  -NMR: precise measurement of |g I | RF (MHz)  asymmetry  strongly deformed intruder I  = 1/2 + g.s. of 31 Mg, G. Neyens et al, PRL 94, (2005)  from Q S measurements via  -NMR: Q S ( 11 Li) > Q S ( 9 Li)  p-n interaction + halo n orbitals, D. Borremans, Ph.D. Thesis, 2004, KU Leuven, R. Neugart et al.

 -NMR spectroscopy at DESIR  with I ≥ pps, T ½ from 1 ms to 10 s, beam purity > 50 % :  in combination with collinear laser spectroscopy whenever the spin and the configuration of the state is not known  in case Q S is to small to be measured by collinear laser spectroscopy  N~50:  g factor of neutron-rich Ga and Cu isotopes to determine where the inversion of the  p 3/2 and  f 5/2 orbitals occurs  persistence of the N=50 shell gap from the g.s. configuration of N=49 ( g 9/2 ) and N=51 ( d 5/2 ) even Z nuclei ( 81,83 Ge, 79,81 Zn, 77 Ni)  N~82:  g.s. configuration from g I measurements

Double laser and RF spectroscopy in traps  In a Paul trap (low magnetic field)  In a Penning trap (high magnetic field)  precise determination of the hyperfine constants A, B as well as C (magnetic octupole moment) and D (electric exadecapole moment) = high-order deformation parameters  RF scan of hyperfine transitions between Zeeman levels  precise determination of the hyperfine constant A  hyperfine anomaly (nuclear magnetization extension) constraining the computation of the nuclear wave function  high precision on g I (  g I /g I ~ )  looking at different isotopes: neutron radius variations + PNC  No Doppler effect  accurate measurements

Double laser and RF spectroscopy in traps DESIR  at DESIR (I>100 pps, T ½ >100 ms)  Previous results: O. Becker et al., Phys. Rev. A48, 3546 (1993)  high-order deformation in the actinide region: Rn, Fr, Ra, Am  hyperfine anomaly: Au, Eu, Cs

The LUMIERE collaboration F. Le Blanc F. Le Blanc, G. Neyens (  -NMR), P. Campbell, K. Flanagan, S. Franchoo, C. Geppert, M. Kowalska, I. Moore, R. Sifi, C. Theisen, J.-C. Thomas,… and others are welcome !!!