Low-energy experiments at ISOLDE – atomic, nuclear, and fundamental physics Magdalena Kowalska ISOLDE Physics Coordinator

Outline Low-energy part of ISOLDE Interest: nuclear, atomic, and fundamental physics Penning-trap-based studies: ISOLTRAP and WITCH Laser spectroscopy: COLLAPS, CRIS, RILIS Decay studies Summary and outlook 2

Low-energy ISOLDE 3 Target stations HRS & GPS Mass-sep. HRS ISCOOL RILIS REX-TRAP PS-Booster 1.4 GeV protons 3×10 13 ppp ISOLTRAP CRIS COLLAPS NICOLE WITCH Travelling setups keV ion beam eV energy spread and small emittance Possibility to bunch beam (  s bunches) Many fixed and travelling setups Collection points (applications)

Low energy: interest 4 Nuclear Physics Nuclear Decay Spectroscopy Structure of Nuclei Exotic Decay Modes Atomic Physics Laser Spectroscopy and Direct Mass Measurements Radii, Moments, Nuclear Binding Energies Nuclear Astrophysics Dedicated Nuclear Decay Studies Element Synthesis, Solar Processes f(N,Z) Fundamental Physics Direct Mass Measurements, Dedicated Decay Studies – WI CKM unitarity tests, search for  correlations, right-handed currents

Laser spectroscopy 5 ISCOOL RILIS CRIS COLLAPS

Laser spectroscopy and nuclear physics 6 - Spin (orbital+intrinsic angular momentum), parity (I  ) - Nuclear g-factor and magnetic dipole moment (g I and  I ) - Electric quadrupole moment (Q) -Charge radius ( ) Give information on: - Configuration of neutrons and protons in the nucleus - Size and form of the nucleus volume deformation pairing 0d 5/2 1s 1/2 0d 3/2 I p =2 +  = d 5/2 1s 1/2 0d 3/2 I p =2 +  = g I and  I Q Q<0 oblate Q=0 spherical Q>0 prolate II 0d 5/2 1s 1/2 0d 3/2 1/2 + 3/2 + 0d 5/2 1s 1/2 0d 3/2

Laser and  -NMR Spectroscopy 7 Detection method depends on the case => optimised for best S/N ratio Observables: Hyperfine structure, isotope shifts, Nuclear Magnetic Resonance Information: ground-state spin (+parity assignment), charge radius, moments => Probing single-particle and collective properties Laser beam, Laser on fixed frequency Ion beam Electrostatic deflection Retardation zone Neutralisation region Excitation / Observation region Collinear laser spectroscopy Beam from ISOLDE Beta-NMR COLLAPS setup

Charge radii of Ne isotopes 8 Intrinsic density distributions of dominant proton FMD configurations Laser spectroscopy Geithner et al, PRL 101, (‘08) Marinova et al, PRC (‘12) Open projects: IS484: Ground-state properties of K-isotopes from laser and β-NMR spectroscopy IS497: Laser Spectroscopy of Cadmium Isotopes: Probing the Nuclear Structure Between the Neutron 50 and 82 Shell Closures IS517: Determination of the Magnetic Moment of 140-Pr IS519: Shell structure and level migrations in zinc studied using collinear laser spectroscopy IS529: Spins, Moments and Charge Radii Beyond 48Ca

CRIS Collinear Resonant Ionisation Spectroscopy High sensitivity, lower resolution -> perfect for heavy ions 9 First physics experiment in 2011: HFS and decay of 207Fr Open projects: IS471: Collinear resonant ionization laser spectroscopy of rare francium isotopes IS531: Collinear resonant ionization spectroscopy for neutron rich copper isotopes

RILIS Resonant Ionisation Laser Ion Source; one way to ionise produced atoms Nd: YAG pumping dyo or Ti:Sa lasers, with possibility of doubling to quadrupling Atomic physics: Used to determine ionisation schemes and ionising potential of chemical elements with no stable isotopes (e.g. polonium, astatine) Nuclear physics: laser spectroscopy -> electromagnetic ground state properties 10 3 Ti:Sa lasers Harmonic generation unit for Ti:Sa system Nd:YAG pump laser for the Ti:Sa lasers Dye lasers with 2 nd harmonic generation and UV pumping option Nd:YAG laser for dye pumping or non resonant ionization Narrow band dye laser for high resolution spectroscopy or isomer selectivity Dye laser 3 rd harmonic generator

RILIS – nuclear structure 11 T.E. Cocolios et al., PRL 106 (2011) M. Seliverstof et al., EPJ A41(2009) 315 H. De Witte et al., PRL 98 (2007) Changes in charge radii of heavy nuclei Open projects: IS456: Study of polonium isotopes gs properties by simultaneous atomic- and nuclear-spectroscopy IS466: Identification and systematical studies of the electron-capture delayed fission (ECDF) in the lead region - Part I: ECDF of 178,180Tl and 200,202Fr isotopes IS511: Shape coexistence in the lightest Tl isotopes studied by laser spectroscopy IS534: Beta-delayed fission, laser spectroscopy and shape-coexistence studies with radioactive At beams

RILIS – atomic structure 12 Astatine beams: Determination of ionising potential Identification of new atomic transitions Comparison with atomic theory Recent projects: Polonium Astatine

Penning-trap studies 13 REX-TRAP ISOLTRAP WITCH Ion manipulation with rf in Penning traps Possibility of purifying the ion ensembles

ISOLTRAP 14 Cyclotron frequency in magnetic field => atomic mass determination of cyclotron frequency (R = 10 7 ) removal of contaminant ions (R = 10 5 ) Bunching of the continuous beam Beta- and gamma decay studies 10 ms, 1-10% ms, >50% 50 ms -1 s, 100% 50 ms -10 s, 100%

ISOLTRAP 15

ISOLTRAP 16 High-precision mass of 82Zn (Oct 2011): after several attempts at ISOLTRAP and other Penning traps Nuclear structure: N=50 shell closure Astrophysics: r-process path Astrophysics: neutron star structure Combined ISOLDE technical know-how: neutron-converter, quartz transfer line, laser ionisation IS490: Masses of noble gases IS498: High-Precision Mass Measurements in the Rare-Earth Region to Investigate the Proton-Neutron Interaction IS518: First Study of the Stability of the N=126 Shell Closure IS535: Penning-trap mass spectrometry of neutron-rich copper isotopes for probing the Z = 28 and N = 50 shell closures

WITCH Weak Interation Trap for Charged particles -> fundamental studies Goal: determine  correlation for 35 Ar with (  a/a) stat  0.5 % -> energy spectrum of recoiling ions with a retardation spectrometer Use a Penning trap to create a small, cold ion bunch 17 M. Beck et al., Eur. Phys. J. A47 (2011) 45 M. Tandecki et al., NIM A629 (2011) 396 S. Van Gorp et al., NIM A638 (2011) 192 recoil ion energy (eV) # recoil ions Ar recoil spectrum ( preliminary ; 4 h ; 5 x 10 5 at/  C) two differ. normalizations (agree within error bars) June 2011 data: First high-statistics run in Nov 2011(data analysis ongoing) Open experiment: IS433: Search for new physics in beta- neutrino correlations using trapped ions and a retardation spectrometer

Decay studies 18 (ISOLTRAP) (CRIS) Travelling setups

Beta-delayed fission Travelling alpha-decay station looking at beta-delayed fission Hg (Z=80, N=100, N/Z=1.25) does not fission in two semi-magic 90 Zr(Z=40,N=50) IS466: Identification and systematical studies of the electron-capture delayed fission (ECDF) in the lead region IS534: Beta-delayed fission, laser spectroscopy and shape-coexistence studies with radioactive At beams

Exotic decays of light nuclides Looking at both emitted particles and gamma rays 20 Open projects: IS445: Experiments with the newly available Carbon beams at ISOLDE - Resonance scattering and decay studies IS476: Studies of beta-delayed two-proton emission : The cases of 31Ar and 35Ca IS507: Study of the beta-decay of 20Mg IS525: Study of multi-neutron emission in the beta-decay of 11Li IS541: Search for beta-delayed protons from 11Be Double Sided Silicon Strip Detectors

Exotic decays of heavy nuclei 21 Proposal by U. Datta Pramanik (Saha): Experimental investigation of decay properties of neutron deficient Ba isotopes and test of Ba beam counts (IS545) Kolkata, Valencia, Geneva, Aarhus, Goteborg, Grenoble, New Delhi, Santiniketan, Cologne, Edinburgh Use Si detector for particle detection and HpGe or LaBr3 detectors for gamma detection Aim: look for exotic decay modes (alpha and possible cluster emission)

Other decay studies Fast-timing studies Change of electron capture nuclear decay rate under compression Classical  decay studies (e.g. Mn, Hf) 22 Travelling setups Gamma spectroscopy with BaF2 crystals (very fast response, <ps lifetime studies) Open experiments: IS441: Ultra fast timing measurements at 78Ni and 132Sn IS474: Fast-timing studies of nuclei below 68Ni populated in  -decay of Mn isotopes IS467: Beta-decay studies of neutron rich 61-70Mn isotopes with the new LISOL beta-decay setup IS537: Properties of neutron-rich hafnium high-spin isomers Scintillators and Ge detectors Precision measurement of the half-life of 107In large and small lattice environments Kolkata, Raniganj, Geneva, Cologne

Trap- or laser-assisted decay studies Decay stations behind ISOLTRAP and CRIS Isobar and even isomer purification in a Penning trap or by laser ionisation Studies of radionuclides suffering from contamination 23 Open projects at ISOLTRAP: IS463: Mass measurements and decay studies on isobarically pure neutron-rich Hg and Tl isotopes IS513: Study of the odd-A, high-spin isomers in neutron-deficient trans-lead nuclei with ISOLTRAP Open projects at CRIS: IS463: Mass measurements and decay studies on isobarically pure neutron-rich Hg and Tl isotopes IS513: Study of the odd-A, high-spin isomers in neutron-deficient trans-lead nuclei with ISOLTRAP

Other fixed low-energy setups Presently: Total Absorption Spectrometer Low Temperature Orientation beta-NMR setup In the future: Fixed versatile decay station: collaboration being setup, contributions welcome MOT (Magneto-Optical Trap) for weak-interaction studies 24

How to perform such studies at ISOLDE Join existing collaboration Put a new letter of intent or proposal and involve group(s) familiar with ISOLDE Check existing experiments at ex.htm&main=experiments/explist.php ex.htm&main=experiments/explist.php Planning: next experimental campaign in 2014 (mostly for low- energy physics); proposals due in

Summary and outlook ISOLDE provides a wealth of radionuclides at low energies Beams are monoenergetic, have small emittance, and can be bunched Physics interest: atomic, nuclar, fundamental physics Studies performed by several fixed setups and many travelling experiments Techniques: decay studies, laser spectroscopy, Penning-trap studies Results: everywhere in the nuclear chart How to perform such studies: join or create a collaboration and put a proposal with large chances to run in

Thank you for your attention 27