Maria J. G. Borge PH-Dept, CERN Highlights of the ISOLDE Facility and the HIE ISOLDE Project Maria J. G. Borge PH-Dept, CERN

ISOLDE Facility PSB upgrade (2018) intensity (2uA -> 6uA ) ISOLDE is the CERN radioactive beam facility Nuclei produced via reactions of high intensity high energy proton beam with thick targets. Provides low energy or post-accelerated exotic beams targets HIE-ISOLDE intensity (2uA -> 6uA ) energy (1.4 -> 2GeV) PSB upgrade (2018)

Produced Nuclei: ISOLDE 45y Experience Over 20 target materials (carbides, oxides, solid metals, molten metals and molten salts) and ionizers, depending on beam of interest operated at high temperature 3 types of Ion-sources: Surface, Plasma, laser > 1300 nuclides of over 70 chemical elements produced Target p+ p+ ISOLDE today offers the largest range of available isotopes of any ISOL facility worldwide.

ISOLDE: Research with Radiactive Nuclei Nuclear physics and atomic physics Material science and life sciences Fundamental interactions Nuclear astrophysics neutrons protons Techniques: all available at ISOLDE Laser spectro-scopy Beta-detected NMR Ion traps Decay spectro-scopy Coulomb excitation Nucleon-transfer reactions half-life mass e-m moments Transition probability radius Spin, parity decay pattern mgb@cern.ch

Experimental hall (2012) HIE-ISOLDE Beams of 30-60 keV Beams of 3 MeV/u Decay spectroscopy Coulomb excitation Transfer reactions Laser spectroscopy Beta-NMR Penning traps Applications: Solide state Life Science Target stations HRS & GPS Mass-sep. HRS ISCOOL RILIS REX-ISOLDE PS-Booster 1.4 GeV protons 3×1013 ppp ISOLTRAP CRIS COLLAPS NICOLE MINIBALL and T-REX WITCH Travelling setups ASPIC Collection points HIE-ISOLDE TAS IDS

Masses & New Magic Numbers MAtom = N•mneutron + Z•mproton + Z•melectron - (Batom + Bnucleus)/c2 51,52Ca 53,54Ca Nature. 498 (2013)346 δm/m < 10-10 δm/m = 10-6 – 10-8 B N = 28 N Mágico 5 cm N = 32 No Mágico The free cyclotron frequency is inverse proportional to the mass of the ions! S2n = Bnucl(Z,N) – Bnucl(Z,N-2) Test of Nuclear Forces! Talk´s of M. Block, A. Bracco mgb@cern.ch

Laser spectroscopy Probe the hyperfine structure of the energy levels of the electron Scan the laser frequency of the resonant transition Nuclear observables extracted with model-independence: Ex GS Magnetic dipole moment Electric quadrupole moment Nuclear spin Change in mean square charge radii

Recent ISOLDE Results (4/2015) Expertise Target+Ion source+RILIS Beam manipulation with MR-ToF Leading to high mass separation Decay spectroscopy Exp Hyperfine interactions Nuclear Structure Au Using the RILIS lasers to measure the hyperfine structure of astatine isotopes Two different techniques Alpha spectroscopy using the Windmill setup Selective single ion counting using MR-ToF MS of the ISOLTRAP setu Odd even stagering in the neutron deficient nuclei reduced to the mid-shell region. As predicted it becomes spherical afterwrads The deformed Au isotopes are symetric about mid-shell N=104 Return to sphericity in 179Au Stagering in 178Au Bonn et al., PLB38 (1972) 308 Ulm et al., Z Physik A 325 (1986) 247

Post-accelerator: REX-ISOLDE REX-ISOLDE started in 2001 > 100 different beams Total efficiency : 1 -10 % 1+ to A/Q = 2 – 4.5 Primary target Protons from PS ISOLDE Ions are cold in the large aceptance rex-trap to effectively enter in the Electron beam ion source that produce a charge breeding between 3 al 4.5. last year the A/Q ratio 2 was successfully proved. The 4-rod-RFQ is designed to accelerate radioactive ions with a charge-to-mass ratio larger than 1/4.5 from 5 keV/u to 300 keV/u . The RF Quadrupole field provides transverse focusing for the low energy ions while a modulation of the four rods performs a smooth bunching and acceleration of the injected 100 µs bunch. The IH-Structure (IHS) [8] is a compact cavity containing separated regions of acceleration and focusing, including a triplet of quadrupoles and a section of drift tubes operating as a re-buncher, boosting the beam from 0.3 MeV/u to an energy value between 1.1 and 1.2 MeV/u, by providing an effective voltage of up to 4.2 MV. The whole structure has 20 gaps and a total length of 1.5 m.

Physics program @ REX Higher Coulex Cross section Coulomb excitation with Miniball: collectivity versus individual nucleon behaviour 184,186,188Hg Probing shape coexistence 20 40 82 50 222,224Ra; 220,222Rn Probing Pear Shape Gaffney Nature 2013 82 Higher Coulex Cross section Need to go to 5 MeV/u Multi-step Coulex 110Sn; Cederkäll, PRL 2007 106,108Sn, Cederkäll, PRL 2008 50 122,124,126Cd 138,140,142,144Xe 140,148,150Ba Evolution of collectivity around 132 Sn 70Se, shape coexistence, Hurst PRL 2007 96Sr, 88Kr, 92Kr, PRL 2012 28 67,69,71,73Cu, Stefanescu et al., PRL 2008 68,70Cu, isomeric 68Cu, Stefanescu , PRL 2007 74,76,78,80Zn Probing large scale shell model, Van der Walle, PRL2007 30,31,32Mg, Niedermaier PRL2005, H. Scheit 20

Transfer Reactions @ REX 30Mg(t,p)32Mg (N=20) Few-nucleon transfer reaction studies: single-particle properties halo and cluster structures 20 40 82 50 82 Need to go to 10 MeV/u Transfer reaction studies 50 t(72Zn,p)73Zn Hellgartner t(44Ar,p)46Ar Nowak d(66Ni,p)67Ni Diriken t(66Ni,p) 68Ni Elseviers d(78Zn,p)79Zn Orlandi 28 d(30Mg,p)31Mg, K. Wimmer, PRL 2010 Light nuclei, halos & clusters d(8Li,p)9Li*; Tengborn PRC (2011) d(9Li,p)10Li d(11Be,p)12Be Johansen PRC (2013) 20

The HIE-ISOLDE project Energy: 4.5 – 10 MeV/u Intensity: x10 in power Beam Quality Higher Energy 2015 Purity & Beam Quality The HIE-ISOLDE (High Intensity and Energy) project will provide major improvements in energy range, beam intensity and beam quality. A major element of the project will be an increase of the nal energy of the post-accelerated beams to 10 MeV/u throughout the periodic table. The rst stage will boost the energy of the current REX LINAC to 5.5 MeV/u where the multistep Coulomb excitation cross sections are strongly increased with respect to the previous 3 MeV/u and many transfer reaction channels will be opened. The construction of the Linac is underway and the full physics program with post accelerated beams up to 5.5 MeV/u will start in 2016. Higher Intensity 2020 ISOLDE mgb@cern.ch

High Energy Increase HIE-ISOLDE 5.5 MeV/u A/Q = 4.5 10 MeV/u A/Q = 4.5

High Energy Upgrade Procurement for elements of HIE-ISOLDE phase II started ! REX Beam@ 3MeV/u phases wk 18/2015 Wk 48/2015 5.5 MeV/u I 10 MeV/u wk 02/2017 wk 02/2017 10 MeV/u II 0.3 – 10 MeV/u III Phase II is in MTP; money from collaboration also firmly committed. Phase III also in MTP but w/o funding; low-beta CM will require subtantial design, and low-beta cavities subtantial R&D Aim is to use present momentum, use existing options (as far as possible), and not spend much extra effort and time in looping around with other suppliers. Legend:

First Cryomodule in place for 4.3 MeV/u 2nd of May 2015 0.5 km/h

Installation Cryomodule 27th of May DG Visit to ISOLDE 2nd May 2015 Cold to 4K Commissioning July-Sept 2015

HEBT installation May 2015 June 2015 XT01 XT02 XT03 XT03: No elements but full infrastructure in place May 2015 S. Maridor XT01 HW done. Alignment done. Hall probes & field regulation racks to be installed . XT00/02: dipoles arrival end May.Finish installation End of June 2015. XT03 will be kept with complete infrastructure but without elements. XT02

Physics @ HIE-ISOLDE Isospin symmetry 28 experiments already approved 600 shifts already allocated for day 1 physics Isospin symmetry Collectivity versus Single Particle Magic numbers far from stability Shape Coexistence Quadropole and octupole degrees of freedom mgb@cern.ch

Instrumentation Miniball + T-REX (upgrade planned) : COULEX + Transfer Approved Miniball + T-REX (upgrade planned) : COULEX + Transfer Multipurpose reaction chamber CORSET chamber for fusion-fission reactions SPEDE: added to Miniball+T-REX Helios type Spectrometer (Hall @ TSR) MAYA/ACTAR: resonant scattering + transfer Zero type spectrometer TSR storage ring 22 2 1 2 1 gas volume incoming beam electric field segmented plane amplification zone magnetic field

First planned experiments @ HIE-ISOLDE Beam line XT01 Collectivity versus Single Particle in Zn region Shape Coexistence in the lead region 182,184Hg, 186,188Pb protons Beam Line XT02: Reaction experiment -Use of Stripper foils (12C,180) Supression 10-5 – 10-6 9Li(t,p) A/q = 3 Explore dipole resonances in 11LI neutrons

Evolution of collectivity around N=40 and N=50 protons neutrons j> = l+1/2 j> = l’+1/2 j< = l’-1/2 g9/2 f7/2 f5/2 N = 50 N = 40 N=40 Monopole migration of proton single particle states; collective states and proton intruder states in the n-rich Cu Beta decay studies (S. Franchoo,PRL81 (1998)); Laser spectroscopy (K. Flanagan,PRL103 (2009)); Coulomb excitation (I. Stefanescu,PRL100 (2008)) Low-lying proton and neutron intruder states in and around 68Ni (D. Pauwels, PRC78 (2008) 041307 & C 82, 027304 (2010) Swift onset of deformation below Z=28 (Fe: W. Rother PRL106 (2011); Cr: A. Gade PRC81 (2010)) Restored N=50 shell at 80Zn:Coulomb excitation (J. Van de Walle, PRL99 (2007) 142501) Z=28 Colored boxes: nuclei studied by Coulex at REX-ISOLDE in different experimental campaigns Transfer reactions 78Zn(d,p) 79Zn  66Ni,(t,p) 68Ni 66Ni(d,p)67Ni 72Ni,(t,p) 74Ni Coulomb excitation experiments even-mass 74-80Zn, odd-mass 67-75Cu, even-mass 68-72Cu Isomeric beams Single particle energies: location of the orbital above the Z=28 and N=40, N=50 gaps; New and extensive spectroscopic information on 67Ni, 68Ni, 69Zn, 70Zn to serve as benchmarks for new Shell Model calculations using different interactions; B(E2) to probe collectivity versus single-particle character of the excited state 56Ni 68Ni What is the nature of the N=40 shell closure? How large is the N=50 shell gap at 78Ni? What does the effective proton-neutron interaction look like ?

Previous Measurements of Zn Isotopes 2+ Maximum collectivity at 74Zn Agreement between previous results from Miniball and AGATA [PRC87 (2013) 054302] Large disagreement for 74Zn B(E2) The reduced value for 74Zn is not predicted by any model. Remeasure the half-life of 4+ state is needed.

Coulomb Excitation 74-80Zn @ 4.5 MeV/u Measure B(E2: 4+2+) and B(E2: 6+4+) Clarify discrepancies with half-lifes measurements Observation of 4+ in 80Zn Identification of non Yrast states

IS561: Coulomb excitation of (186),188Pb Region of shape coexistence Deduce level scheme of 188Pb @ Argonne (Dracoulis Phys. Rev C 67, 051301(R) 2003) The partial level scheme of 188Pb is shown here, including isomeric states that are associated with three different states. This is from gammasphere data by Dracoulis et al. By means of missing gamma-ray analysis, they extracted enhanced E0 components for the interband transitions between states with same spin and parity. E0 do not only help with spin assignments, but also carry out information of mixing. From Janne Pakarinen

Aim of the IS561 Experiment: 188Pb Directly measure shapes of the “bandhead” 2+ states Probe collectivity of bands associated different shapes Determine the long time discrepancy of the position of the 0+ states Investigate mixing via measurement of the E0 transitions

Thanks for your attention ! Conclusions Plenty of challenging physics at ISOLDE, and many cases waiting for the starting of HIE-ISOLDE! Many new devices and groups have been attracted by the increase of energy of the post-accelerated beams. HIE-ISOLDE Phase 1: Start of the 4.3 MeV/u, physics program in autumn 2015. Reaching 5.5 MeV/u in Spring next year. We have identified the experiments that could be done in the 4 weeks of physics expected in 2015. The nuclear physics community is expecting that CERN will provide this facility on time. Thanks for your attention !