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Laser spectroscopy studies at the DESIR facility of SPIRAL2. DESIR @ SPIRAL2. organi z ation & scientific program. layout of the facility. status and perspectives. Laser spectroscopy @ DESIR: the LUMIERE project. physics cases. experimental techniques. research program. - PowerPoint PPT Presentation
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DESIRDESIR @ SPIRAL2
organization & scientific program
layout of the facility
status and perspectives
Laser spectroscopy @ DESIR: the LUMIERELUMIERE project
Laser spectroscopy studiesLaser spectroscopy studies at the at the DESIRDESIR facility of facility of SPIRAL2 SPIRAL2
J.C. Thomas – XVth Colloque GANIL, Giens 2006
physics cases
experimental techniques
research program
DESIRDESIR
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 »
http://spiral2ws.ganil.fr/2005/lowenergy/program/presentations/
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): 6He, 19Ne, 32,35Ar @ ~ 30 keV
talk by A. Merytalk by A. Mery
DESIRDESIR organizationorganization
Working groups / correspondents:
- Beam handling and beam preparation / [email protected]
- Laser spectroscopy / [email protected]
- Decay spectroscopy / [email protected]
* spokes-person: B. Blank, [email protected]
* GANIL correspondent: J.-C. Thomas, [email protected]
Links to SPIRAL2 project management:
- Scientific program: M. Lewitowitcz
- Installation: M.-H. Moscatello
DESIRDESIR physics programphysics 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 1500m2
Availability from day 1
Run in parallel with post-accelerated beamsFast change of the mass settingNeutron-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
TheThe DESIRDESIR facility @ SPIRAL2facility @ SPIRAL2technical requirementstechnical requirements
LINAG
Production building
GANIL facility
LIRAT
DESIR
TheThe DESIRDESIR facility @ SPIRAL2facility @ SPIRAL2layoutlayout
LINAG
Production building
DESIRHRS
Ident. Station
Exp. Area
GANIL
GANIL facility today
DESIR building - UndergroundDESIR building - Underground
DESIR building -DESIR building - Ground floorGround floor
Laser Laser SpectroscopySpectroscopy
Decay studiesDecay studies
Other Other purposespurposes
Fundamental Fundamental InteractionsInteractions
Spectroscopy Spectroscopy of trapped of trapped
beamsbeams
talk by A. Herlerttalk by A. Herlert talk by M.J.G. talk by M.J.G. BorgeBorge
talks by A. Mery and N. Severijnstalks by A. Mery and N. Severijns
talk by P. Delahayetalk by P. Delahaye
this talk and P. Mueller
Cooling/BunchingCooling/Bunching
Status of theStatus of the DESIRDESIR ProjectProject
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
LoILoI to be submitted in October 2006 (Contact: B. Blank)
Presentation of the DESIR Project to the IN2P3 SC in July 2006
Synergies with other facilitiesSynergies 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 Towards DESIRDESIR: LIRAT extension: LIRAT extension Multi-beam facility (physics program 2012)
Tests and development for SPIRAL2 & DESIR
LIRAT today
SPIRAL2SPIRAL2
11++ nn++
LPC TrapLPC Trap
TestsTests
Spec.Spec.
TheThe LUMIERELUMIERE project @ project @ DESIRDESIRLaser Utilisation for Measurement and
Ionization of Exotic Radiaoctive Elements
Spokes-person: F. Le Blanc, [email protected]
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: <r²>, I, Qs, I
from precise measurements of the hyperfine structure constants
collinear laser spectroscopy + -NMR
double laser + RF spectroscopy in traps
Atomic hyperfine structureAtomic hyperfine structure
Interaction between an orbital e- (J) and the atomic nucleus (I,I,QS)
results in a hyperfine splitting (HFS) of the e- energy levels
J
n
FEHFS
1)J(J1)I(I1)F(FK with
I.J(0)Hμ eIA Hyperfine structure constants: and (0)Ve zzSQB
1)I.J1)(2J2(2I
1)1)J(JI(I1)K(K43
..K2
ΔEHFS
BA
Collinear laser spectroscopy: / ~ 10-2, QS/QS ~ 10-1 for heavy elements
Isotope shift measurementsIsotope shift measurements
Frequency shift between atomic transitions in different isotopes of the same chemical element
related to the mass and size differences
A'A,2SMSNMS
A' A, rF.A.A'
A)(A').K(K
J1, F1
J2, F2
J1, F1
J2, F2
A,A’
mean square charge radius variations with a precision ~ 10-3
study of nuclei shape (deformation)
previous experiments:
Isotope shift measurementsIsotope shift measurements
N~82 N~104
onset of deformation at N=82 (slope ↔ rigidity)
dynamical effects (vibration)
shape coexistence
shape transition (even-odd staggering)
COMPLISCOMPLIS
with I ~ 103-104 pps:
Isotope shift measurements at Isotope shift measurements at DESIRDESIR
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)
)21
1)(m)(.(3cos1)4I(2I
Q3h.Lh.ΔE 2
1-mm,
θ
-NMR spectroscopy-NMR spectroscopy
h
.B.L
0N Ig
-asymmetry in the decay of polarized nuclei in a magnetic field
Zeeman splitting related to gI and QS
I
M+I
M-I
resonant destruction of the polarization (i.e. -asymmetry) by means of an additional RF magnetic field
h
.V. ZZQ
SQewith and
B0
gI/gI ~ 10-3, QS/QS ~ 10-2
complementary technique to collinear laser spectroscopy
suitable for light elements (low QS values)
previous experiments at COLLAPSCOLLAPS:
Collinear laser andCollinear laser and-NMR spectroscopy-NMR spectroscopy
from the position of hyperfine transitions: spin assignment and sign of gI for the g.s. of 31MgHFS 31Mg1+
from -NMR: precise measurement of |gI|
RF (MHz)
as
ym
me
try
strongly deformed intruder I = 1/2+ g.s. of 31Mg, G. Neyens et al, PRL 94, 022501 (2005)
from QS measurements via -NMR: QS(11Li) > QS(9Li) p-n interaction + halo n orbitals, D. Borremans, Ph.D. Thesis, 2004, KU Leuven, R. Neugart et al.
-NMR spectroscopy at -NMR spectroscopy at DESIRDESIR
with I ≥ 5.103 pps, T½ 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 QS 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 p3/2 and f5/2 orbitals occurs
persistence of the N=50 shell gap from the g.s. configuration of N=49 (g9/2) and N=51 (d5/2) even Z nuclei (81,83Ge, 79,81Zn, 77Ni)
N~82:
g.s. configuration from gI measurements
Double laser and RF spectroscopy in trapsDouble 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 gI (gI/gI ~ 10-4)
looking at different isotopes: neutron radius variations + PNC
No Doppler effect accurate measurements
Double laser and RF spectroscopy in trapsDouble laser and RF spectroscopy in traps
at DESIRDESIR (I>100 pps, T½>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 Constant
151Eu+ [Hz] 153 Eu+ [Hz]
A 1 540 297 394 (13) 684 565 993 (9)
B - 660 862 (231) -1 752 868 (84)
C 26 (23) 14 (7)
D -6 (5) -5 (2)
hyperfine anomaly: Au, Eu, Cs
TheThe LUMIERELUMIERE collaborationcollaboration
F. Le BlancF. 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 !!!