1 stephan ettenauer for the TITAN collaboration Experimental Program on Experimental Program on Halo Nuclei Halo Nuclei with non-accelerated Beams at with non-accelerated Beams at TRIUMF TRIUMF Weakly Bound Systems in Atomic and Nuclear Physics, March 2010
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1 stephan ettenauer for the TITAN collaboration Experimental Program on Halo Nuclei with non-accelerated Beams at TRIUMF Weakly Bound Systems in Atomic.
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stephan ettenauer for the TITAN collaboration
Experimental Program on Experimental Program on
Halo Nuclei Halo Nuclei with non-accelerated Beams at TRIUMFwith non-accelerated Beams at TRIUMF
Weakly Bound Systems in Atomic and Nuclear Physics, March 2010
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Outline
•Overview: Experimental Probes on Halo•Production of Halo Nuclei•non-accelerated Halos @ TRIUMF
– Laser Spectroscopy– Mass Measurements in Penning Trap
•Conclusion & Outlook
TRIUMF
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Halo Nuclei
Two-proton halo
One-neutron halo
Two-neutron halo
One-proton halo
Four-neutron halo
Binary system
K. Tanaka et al., PRL 104, 062701 (2010)
22C
In 1985 Tanihata et al.:•interaction cross section measurements(transmission experiment)•11Li much larger than expected from
general rule of stables: RN ~r0 A1/3 •extra neutrons (or protons)in classically forbidden region
I. Tanihata et al., PRL 55, 2676 (1985)
Transmission Experiment
T. Nakamura et al., PRL 103, 262501 (2009)
31Ne
New Candidates:
would be heaviest nuclear halo systempossibly p - wave 1n halo
S2n=10 keV
S2n=420 keV
⇒ mass required
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beta
Experimental Probes for Halos
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ReactionCross Sections
TransferReaction
KnockoutReactions
ElasticScattering
Breakup
MagneticMoment
Beta Decay
Beta DelayedParticle Emission
•accelerated beams•model depend.
stopped orlow E beam
Mass
Atomic LaserSpectrosco
py
this talk
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Rare Isotope Production
Beam cooler
*
~ 60 keV
~ 10 MeV/uExperiments Experiments Experiments
~ 10 MeV/u~ 100 MeV/u
ExperimentsBeam cooler
~ 20 keV
Charge-
breeder
Charge-
breeder
ISOL (TRIUMF, ISOLDE@CERN):Production: slow (~5 ms) BUT high intensityLow beam energy, ideal for decay and trap exp.Good beam quality (even cooled) & purityPost-acceleration for reaction studiesBUT element selective ionization•⇒ some elements not possible!
• quadrupolor rf- field• extraction: through B-field Er to El
• El measured by TOF • minimum at νc
• comparison to well known isotope
Mass measurements in the MPET
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Precise & Accurate
accurate, but not precise
precise, but not accurate
line width (FWHM):
⇒ resolution:
⇒ even for Trf ∼ 10ms
•exact theoretical description
•even for non-ideal traps
•off-line tests with stables ⇒ control over systematics for TITAN: < 5 ppb possible
L.S. Brown and G. Gabrielse, Rev. Mod. Phys. 58, 233 (1986)G. Bollen et al., J. Appl. Phys. 88, 4355 (1990)M. König et al., Int. J. Mass Spect. 142, 95 (1995)M. Kretzschmarr, Int. J. Mass Spect. 246, 122 (2007)
G. Bollen et al., J. Appl. Phys. 88, 4355 (1990)G. Gabrielse, PRL 102, 172501 (2009)
M. Brodeur et al, PRC 80, 044318 (2009)
6Li
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Mass of 11Li
M. Smith et al., PRL 101, 202501 (2008)
11Li
Reference Mass [u]
AME’03 11.043 798(21)
MISTRAL 2005 11.043 715 7(54)
TITAN 2007 11.043 723 61 (69)
rc (11Li) = 2.427(16)(30) fm
eliminates mass as source of uncertainty!two neutron separation energy:
• later this year: electric quadrupole moment of 11Li• TITAN: masses
– to investigate established halos 14Be(2n), 19C(1n), 17Ne(1p)
–needed to decide if halo structure in 22C and 31Ne
⇒ charge radius}Outlook (TRIUMF)
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TITAN collaboration
M. Brodeur, T. Brunner, S. Ettenauer, A. Gallant, V. Simon, M. Smith, A. Lapierre, R. Ringle, V. Ryjkov, M. Simon,
M. Good, P. Delheij, D. Lunney, and J. Dilling for the TITAN collaboration
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Backup SlidesBackup Slides
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AC Stark Effect
R. Sanchez et al., PRL 96, 033002 (2006)
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6He and 8He: Laser Spectroscopy
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He: Comparison with theory
Both the GFMC & NCSM rc agrees with new exp. 6,8He rc Method that provides the closest values to experimentOnly method that uses 3 nucleons interaction (3NI)
GFMC2NI
3NINCSM Produce a physical rc for an unbound nuclei, consequence of using faster Gaussian fall-off and small model space.