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Dubna NUSTAR meeting, Dubna, 5-10 October 2009 Iain Moore (for the LASPEC collaboration) University of Jyväskylä, Finland Laser spectroscopy of short-lived exotic nuclei at FAIR
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
Iain Moore (for the LASPEC collaboration) University of Jyväskylä, Finland
Laser spectroscopy of short-lived
exotic nuclei at FAIR
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
The LASPEC collaboration
In total: 8 countries; 13 institutes; 34 members
Spokesperson: Wilfried Nörtershäuser (GSI) Deputy spokesperson: Iain Moore (JYFL) Technical Director: Christopher Geppert (GSI)
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
Hyperfine structure Isotope shift Isomer shift
Investigation of Nuclear Ground State properties
high-sensitivity & high selectivity… Why OPTICAL??
providing model-independent nuclear data…
Laser spectroscopy at NUSTAR
Motivation:
All proposed techniques are fully developed by the collaboration and have been adapted for on-line work
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
Isotope Shift (IS) Hyperfine Structure (HFS)
AAr
′2δ
Nuclear Spin I
Magnetic Dipole Moment µI
Electric Quadrupole Moment Qs
Hyperfine Anomaly
Mean Square Charge Radii
However, sample preparation is crucial…..
Nuclear ground state properties
Deformation β Triaxiality
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
Good conditions for spectroscopy: highly successful and productive
Target
p+ or
Light Ions
Ion source
Electromagnetic Separation
100 keV
T1/2 ~ 10 ms no reactive elements no refractory elements
T1/2 ~ 1 ms reactive elements refractory elements very modest yields
Ion guide Good conditions
for spectroscopy only if the beam
is cooled
ISOL
IGISOL
Laser spectroscopy – “historically”
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
All elements produced chemically non-selective: T1/2 ~ 1 µs
Thin Target
1 GeV/u
Heavy Ions Electromagnetic
Separation Fragment Separator
Low Quality High-Energy Ion Beam
1 GeV/u
In-flight fragmentation – towards LASPEC
Laser spectroscopy at ISOL facilities is highly developed and has provided nuclear state properties for two decades. LASPEC offers the possibility to make these studies at the limits of stability and lifetime.
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
S-FRS
LEB
7
FAIR – the facility layout
SIS100/300
SIS18 UNILAC
HESR
PANDA
RESR/ CR
NESR
CBM
FLAIR
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
energy buncher
HISPEC
DESPEC ‹―› Gas catcher
MATS + LaSpec
Layout at the Low Energy Branch
AGATA
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
The device transforms high-energy ions from the Super-FRS into a high-quality low-energy ion beam.
Design parameters
Technical challenges
Operation at high density: up to 0.20 mg/cm3, ~1 bar at room
temperature for a cell of length 1 m. Inner diameter 0.25 m. Cryogenic (~60 K), high purity helium gas as stopping medium. At this temperature most of the impurities are frozen out, leading to a maximum extraction efficiency. Efficient transport of ions by DC and RF fields.
High RF amplitude: few hundred Vpp
Small RF electrode spacing: ≤0.25 mm High DC field: >100 V/cm
outer chamber (room
temperature)
inner chamber (down to 60 K)
DC ring electrodes
exit-hole
extraction RFQ
insulation vacuum
RF carpet DC grid electrode
System design
RF carpet
500 rings
4 electrodes/mm
Exit hole : 0.6 mm
Front
Back
The cryogenic ion catcher for high energy ions
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
Laspec atom beamline
Laspec ion beamline β-NMR
Laspec switchyard
Gas catcher
RFQ cooler & buncher section
Common switchyard Multi-reflection TOF mass spectrometer
Layout of MATS and LaSpec experiments (TDR)
Top view
Overview
EBIT
Spectroscopy station Penning traps
- see talk of D. Rodriguez
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
http://www.gsi.de/forschung/ap/projects/laser/survey.html
Clusters and Halos
Refractory Elements around Shell Closures
Further away from Stability
Towards Superheavy Elements
Present status and LASPEC regions of interest
H.-J. Kluge & W. Nörtershäuser, Spectrochimica Acta B 58 (2003) 1031. J. Billowes & P. Campbell, J. Phys. G 21 (1995) 707.
http://www.gsi.de/forschung/ap/projects/laser/survey.html
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140
10
20
30
40
50
60
70
80
90
N
Z01,0002,0003,0004,0005,0006,0007,0008,0009,00010,0011,0012,00Laser Spectroscopy
Log Production Yield
A variety of techniques to reach the limits
Bunched beam spectroscopy
ß-NMR
Coincidence and decay tagged atom/ion spec.
LD-RIS
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
LASPEC sub-projects
Collinear laser spectroscopy of ions (P. Campbell, Manchester)
Optical pumping and collinear laser spectroscopy on atoms (W. Nörtershäuser, Mainz)
ß-nuclear magnetic resonance (G. Neyens, Leuven)
Laser-desorption resonance ionization spectroscopy (M. Seliverstov, Mainz)
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
Collinear Spectroscopy Resonance Ionization (Mass) Spectrometry
Fluorescence detection 104 ions/s β-NMR detection 103 ions/s Collisional ionization 102 ions/s
Pulsed laser desorption 105 ions/s Nuclear radiation detection 1 ion/s Laser ion source 1 ion/s
General applicability ISOL-type beams
Very general applicability Daughter isotopes available
CW lasers utilized High resolution
Pulsed or cw laser applied Medium or high resolution
Background – scattered light Isobaric contamination
Background - non-resonant ions Very low (or zero) contamination
The two workhorses of LaSpec
See my talk tomorrow for details of these two methods !
Dubna NUSTAR meeting, Dubna, 5-10 October 2009 15 15
Mainz TRIGA Reactor
(University Mainz)
Collinear Laser Spectroscopy and Mass Spectrometry
of Long-Lived Trans-Uranium
Elements up to Californium (SHE) +
Short-Lived Fission Products of 235U and 249Cf
(LASPEC & MATS)
T R A P
SOURCE Ketelaer, Krämer et al., Nucl. Instr. Meth. A 594, 162 (2008)
K. Blaum
Prototyping for FAIR: Mainz TRIGA reactor
W. Nörtershäuser
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
quadrupole doublet & steerer plates
retardation & charge exchange cell
10° deflector chamber
Status of the atomic beamline prototype
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
The IGISOL facility, JYFL
50 – 5000 ions per sec
On-going developments, new techniques (JYFL)
P. Campbell, Hyp. Int. 171 (2007) 143
Optical manipulation in an ion beam cooler-buncher (more tomorrow!)
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
Influencing F state population Survival of metastable in rfq
Towards polarization
Mn+ (Z=25)
0 cm-1
43378.510 cm-1
9472.970 cm-1
230.
5714
nm
293.3913 nm
J=3
J=3
J=2
d5 p
d5 s
N=28
3/2-5/2 5/2-7/2 7/2-9/2 9/2-11/2230.5705
230.5710
230.5715
230.5720
230.5725
230.5730
Pum
ping
wav
elen
gth
(nm
)
Collinear laser hyperfine component
Laser spectroscopy around the N=28 shell (2009)
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
Preparing for the new facility at JYFL (2010-2011)
K = 130 MeV
K = 30 MeV
IGISOL
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
1980
Looking back in time…collinear laser spectroscopy
1976 1978
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
by 1990…
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
in 2000…
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
today !
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
at LaSpec in 201X, more elements, even further from stability
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
Operating facilities Facilities under
construction or test Planned facilities
TRIUMF
MSU
CARIBU
IGISOL
COLLAPS CRIS
TRIGA-LASER
LASPEC
SLOWRI
Collinear laser spectroscopy facilities worldwide
Dubna NUSTAR meeting, Dubna, 5-10 October 2009
Thanks to Wilfried, Paul and Peter Dendooven for slides,
and to you for your attention!
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