1. ISOLDE – High-lights and HIE-ISOLDE
Maria J. G. Borge
ISOLDE-PH, CERN
(Isotope Separator On-Line)
IEM-CSIC, Madrid
Exploring the Nuclear Landscape
ISOLDE
1992
1998
2008
HIE-ISOLDE
ISOLDE – High-lights and HIE-ISOLDE
Maria J. G. Borge , CERN, PH-Dept

2. Hot Topics in Nuclear Physics
Physics at
the Femtometer scale

3. Open Questions in Nuclear Physics
How are complex nuclei built from their basic constituents?
strong interaction in nuclear medium
• How to explain collective properties from individual nucleon behavior?
collective versus individual
• How do regular and simple patterns emerge in the structure of complex nuclei?
symmetries
LRP2010
Observables:
Ground-state properties: mass, radius, J, μ, Q moments
Half-lives and decay modes
Transition probabilities
Cross sections
Main models:
Shell model (magic numbers)
Mean-field models (deformations)
Ab-initio approaches (light nuclei)

4. Production of Radiactive Beams @ ISOL Facilities

5. 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 and heavy targets
Provides low energy or post-accelerated exotic beams
intensity (2uA -> 6uA )
energy (1.4 -> 2GeV)
PSB upgrade (2018)

6. ISOLDE at CERN
LHC

7. Produced Nuclei: ISOLDE 45 y Experience
Over 20 target materials and ionizers, depending on beam of interest operated at high temperature
U, Ta, Zr, Y, Ti, Si, …
3 types of Ion-sources: Surface, Plasma, Laser
> 700 nuclides of over 70 chemical elements produced
Target
ISOLDE today offers the largest range of available isotopes of any ISOL facility worldwide.

8. ISOLDE Physics Topics f(N,Z) Many beams Applied Physics
Condensed matter physics and Life sciences
Tailored Isotopes for Diagnosis and Therapy
MEDICIS Project
Many beams
Good beam purity and quality
Best in the World!
High intensity
Nuclear Physics
Nuclear Decay Spectroscopy and Reactions
Structure of Nuclei
Exotic Decay Modes
Fundamental Physics
Direct Mass Measurements, Dedicated Decay Studies - WI
CKM unitarity tests, search for
b-n correlations, right-handed currents
Atomic Physics
Laser Spectroscopy and Direct Mass Measurements
Radii, Moments, Nuclear Binding Energies
Nuclear Astrophysics
Dedicated Nuclear Decay/Reaction Studies
Element Synthesis,
Solar Processes
f(N,Z)

9. Determination of the atomic properties of Astatine
Determination of ionising potential
Identification of new atomic transitions
Comparison with atomic theory
Scan of ionizing laser: converging Rydberg levels allow precise determination of the IP
ISOLDE collaborates with the Short-Lived Nuclei Laboratory which is based on the ISOL facility IRIS at PNPI since 1999.
Study done with 211At as the most suitable isotope ideal for short range radiation source for targeted alpha therapy.
The Determination of IP of At is important to test the atomic models at the level of relativisticand coorelation effects.
This tuning of the model will help in the precdition for superheavies in particular for Z = 117 that shoul dhave similar chemical properties.
The identification for the 3 intermediate states was done at TRIUMF-TRILIS
The most precise method to determine the IP is by the analisis of the converging levels of the rydberg states.
Excitation scheme:
(a): verification of the lowest 2 transition from ground state.
(b)Ionization threshold.
(c) Develop 3 colour scheme.Verfication of levels found with transition 224 nm
(d)Scann over the rydberg states
Ion detection from the alpha-decay of 119At measured in the wind-mill system.
Group lead by Valentin Fedosseev,
Department of Laser Spectroscopy, Institute of Spectroscopy of USSR Academy of Sciences
M. Seliverstov, V. Fedoseev team
IP(At) = (8) eV
Nature Com. 14May2013
DOI

10. Experimental hall Beams of 30-60 keV Beams of 3 MeV/u WITCH ISCOOL
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
Post-accelerated beams
Collection points
TAS

11. COLLAPS – Ne charge radii
Laser spectroscopy & Massses
Intrinsic density distributions of dominant proton FMD configurations
Geithner et al, PRL 101, (‘08)
Marinova et al, PRC84, (‘11)
Drastic changes in the radious from one isotope to next that cannot be explained by the mean field approach where no drastic changes are expected.
FMD = Fermionic Molecular Dynamic Model allows to include coorelations for cluster and halo states.
In fact it reproduces well account well for the cluster and halo states.
The binding energies, deformations, and charge radii of neon isotopes have also been calculated using the more classical mean-field approach. Among then the deformed
RMF = relativistic Mean field with BCS approach of Lalazizis

12. ISOLTRAP: High-precision mass of 82Zn
Combined ISOLDE technical know-how:
neutron-converter, quartz transfer line, laser ionisation
Nuclear structure:
N=50 shell closure
Astrophysics:
r-process path
Astrophysics:
neutron star structure
Comparison of experimental data to state-of-the-art HFB calculations. What can be seen from the plot is that although there is quite good agreement of some models for measured masses, the scatter largely in their predictions for 78Ni.
HFB-D1S: it is the approach by the Bruyeres-le-Chatel group with the Gogny force (Delaroche, Hilaire, Girod et al.), which includes quadrupole correlations; - HFB-Sly4: it is the Skyrme-GCM approach of Bender, Bertsch, Heenen, which includes quadrupole correlations; - HFB-BSk17: it is the Skyrme-HFB calculation of Goriely et al. (HFB-17); - HFB-SkP: it is the Skyrme-HFB calculation of Stoitsov, Dobaczewski, Nazarewicz et al.;
Astrophysics: global, microscopic HFB models (Goriely) are linked to the equation of state of a neutron star. The mass enters as an input parameter to check at what depth in the neutron-star crust what nuclei is energetically allowed to exist and is in equilibrium with the surrounding degenerate electron gas and some free neutrons.
Its determination is important for modelling of the crust of neutron stars , PRL110 (2013) 04110
CERN Courier, 53, n 3, 2013
D. Rodriguez, U. Granada

13. The Magic Number N=32
The properties of exotic nuclei on the verge of existence play a fundamental part in our understanding of nuclear interactions.
Isobars with the same energy but of slightly different mass will be reflected between the electrostatic mirrors. Their time-of-flight is proportional to the square root of the mass. Thus, after some time, the isobars will have separated in time-of-flight, which can be seen on a multi-channel plate detector. In the case of 54Cr and 54Ti, the resolving power is about 10^3, the difference in mass about 10 MeV.
The spectrum in the lower right corner has the same x-axis as the one in the upper right corner. The ion counts are now depicted by the color code, the y-axis is time or number of measurement cycles.
With a closed proton shell, the calcium isotopes mark the frontier for calculations with three nucleon forces from chiral effective field theory.
The measured masses unambiguously establish a prominent shell closure at neutron number N=32, in excellent agreement
with our theoretical calculations. These results increase our understanding of neutron-rich matter and pin down the subtle
components of nuclear forces that are at the forefront of theoretical developments constrained by quantum chromodynamics
Nature 498 (2013) 346

14. M. Beck et al., Eur. Phys. J. A47 (2011) 45
WITCH
Weak Interaction Trap for Charged particles -> fundamental studies
Goal: determine bn correlation for 35Ar 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
June 2011 data
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

15. REX-ISOLDE Total efficiency : 1 -10 % Tested A/q = 2
1+ to A/Q = 3 – 4.5
Tested A/q = 2
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.

16. Halo Nuclei & Reactions
7Be
8Be
9Be
10Be
11Be
12Be
14Be
Halo Nuclei & Reactions
6Li
7Li
8Li
9Li
10Li
11Li
3He
4He
6He
2n-halo 1H 2H
Common “Structural” properties
Rather inert core plus one or two barely unbound extra neutrons
Extended neutron distribution, large “radius”. “halo”
Very few excited states –if any. n
Reaction properties at near-barrier energies:
Is the Optical Model able to describe the scattering of the halo systems ?
 Strong absorption in elastic channel
Large cross section for fragmentation
They are easily polarizable.
Reaction mechanisms and Nuclear effects
of halo nuclei need to be understood
They are easily polarizable:
- In the scattering process the forces between target and core/ halo are different  distortion effects  e.g. Coulomb dipole polarizability
Dobrovolsky et al, NPA766 (2006) 1

17. Elastic scattering of halo nuclei near the Coulomb barrier
10,11Be+64Zn
10Be+64Zn
11Be+64Zn
Di Pietro et al. Phys. Rev. Lett. 105,022701(2010)
Catania, IEM-CSIC, Huleva, Sevilla Collaboration
CDCC calculations
Experimental elastic cross section. reproduced only taking into account
coupling to continuum via the Coulomb and nuclear interactions

18. Scattering of 11,9Li on 208Pb around the Coulomb Barrier
Elastic Scattering
ECM = 23.1 MeV below Coulomb Barrier
Competing process with Elastic Scattering for loosely bound systems
9Li
Direct Breakup
2n-Transfer
11Li
ECM = 28.3 the Coulomb Barrier
9Li
Scattering process dominated by:
- Dipole couplings (coulomb + nuclear)
Coupling to continuum
Good description in a 4-body model
Cubero et al, PRL109 (2012)
IEM-CSIC, Huelva, Seville Collaboration
11Li 18

19. Why to study the N=Z 72Kr Nucleus?
Nuclear structure:
Shape coexistence in the mass region was first proposed for 72Se [Ham74].
72Kr ground state is predicted to be oblate [Dic72] and [Naz85].
First excited 0+ state in 72Kr found to be a shape isomer [Bou03].
Possibility of study np-pairing effects as 72Kr belongs to N=Z line.
[Ham74] J.H. Hamilton et al., Phys. Rev. Lett. 32, 239 (1974)
[Dic72] F. Dickmann et al., Phys.Lett. 38B, 207 (1972)
[Naz85] W. Nazarewicz et al., Nucl. Phys. A435, 397 (1985)
[Bou03] E. Bouchez et al., Phys. Rev. Lett. 90, (2003)
Nuclear astrophysics:
72Kr “waiting point" in rp process.
73Rb is unbound
β decay competes with 2p capture.
rp-process in N=Z nuclei & A=70-80 region

20. Coulomb excitation of 72Kr
Use of submicron Y203 material for target => Yield increase x 10
Coulex Spectra - number of counts in 710 keV peak depends on the shape of 72Kr
Oblate 72Kr expected
The technique
Doppler Corrected for
104Pd target excitation
Both theory and exp agree that is the unique case with oblate low level states and prolates high excites states.
Nevertheless there is no evidence of the sign of deformation of the 2+ state
Doppler Corrected for
72Kr projectile excitation:
150 counts in 710 keV line

21. TAGS @ISOLDE: The case of 72Kr
Conversion electron studies to determine the multiplicities of the low gamma transitions
B(GT) obtained by measuring the intensity of the full gamma de-excitation cascade from each fed level to the ground state.
P. Sarriguren,
Phys. Rev. C 79, (2009)
Briz, ISOLDE Workshop 2012
IEM-CSIC, Strasbourg, Surrey, Valencia
The B(GT) distribution favours oblate deformation!

22. Searching for pear-shaped nuclei at ISOLDE
λ = 2
Octupole correlations enhanced at numbers: Z or N=34, 56, 88, and
N= 134.  Observed Z≈88 & N≈134
Coulomb excitation to directly access E3 transition strengths
B(E3) ≳ 30 s.p.u. gives significant β3
1/3 of all nuclei are bound mostly if they are settle away sphericity into deformed elongated quadrupole shape.
Quantum correlations between nucleons are expected occasionally to favour more exotic shapes.
These special nuclei serve to test these specific correlations.
In quadrupole deofrmed experimental observables are the E2 transitions and Q-moments
In case of pear shapè there are additional E1 and E3 moments.
While the first are very small the E3 are collective > 10 single particle units.
So far the E3 moment has only been determined for 226Ra.
Particular correlations arise when particular momentum J are near the Fermi surface.
Excitation of coherent correlated pairs of nucleons between these states drives the whole nucleus into a pear shape.
Strong octupole correlation leading to pear shapes can arise when nucleons near the Fermi surface occupy states of opposite parity with orbital and total momentum differeing in 3h.
In these cercunstances interleave parity bands with enhanced E1 transitions.
Microscopically driven...
Intruder orbitals of opposite parity and ∆J, ∆L = 3 close to the Fermi level

23. L. P. Gaffney, et al. (2013). Nature, 497(7448), 199–204. doi:10
L. P. Gaffney, et al. (2013). Nature, 497(7448), 199–204. doi: /nature12073
Hangout with CERN: Going pear-shaped ( MORE than 1000 viewers
Different of cross section with different Z targets is apparent
Gamma corrected by doppler shift and only recorded if the recoiling nucleus was detected simultaneously.
Spectra revael strong population of ground state band of positive parity and octupole band of negative parity.
GOSIA code is used to deduced the matrix elements.
The values of E2 and E3 intrinsic moments are given are given the dashed lines define the average.
One can sse that Q3 is large for 224Ra and comparable to 226Ra

24. Physics program @ REX REX-ISOLDE started in 2001
72 different beams already used at REX- ISOLDE of 700 available!
222,224Ra; 220,222Rn
Probing Pear Shape
Nature 497 (2013)199
184,186,188Hg
Probing shape coexistence 20 40 82 50 82
The Limitations of REX-ISOLDE (E 3.1 MeV/u)
Very limited energy flexibility
Operation restricted to pulsed mode
Bunch length is not flexible
Extension to higher energy is difficult
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 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
d(30Mg,p)31Mg, K. Wimmer, PRL 2010 20
Halos & clusters
d(8Li,p)9Li*; d(9Li,p)10Li…

25. Near Future: HIE-ISOLDE project
Approved Dec 2009
Offically started Jan 2010
Yacine Kadi project Leader
Budget 40 M$
Energy Upgrade:
The HIE-ISOLDE project construction of the SC LINAC to upgrade the energy of the post-accelerated radioactive ion beams to 5.5 MeV/u in 2015 and 10 MeV/u by 2017
Intensity Upgrade:
The design study for the intensity upgrade, also part of HIE-ISOLDE, started in 2011, and addresses the technical feasibility and cost estimate for operating the facility at 10 kW once LINAC4 and PS Booster are online.
The HIE-ISOLDE project concentrates on the construction of the SC LINAC and associated infrastructure in order to upgrade the energy of the post-accelerated radioactive ion beams to 5.5 MeV/u in 2015 and 10 MeV/u by 2017

26. Physics addressed with HIE-ISOLDE / IS564
Study of the unbound proton-rich nucleus 21Al with resonance elastic and inelastic scattering using an active target (USC, IEM, MAYA Collaboration)

27. Experiment
To measure resonant elastic, 20Mg(0+), and inelastic, 20Mg(2+), scattering using MAYA to determine energy, spin and parity of the 21Al excited states.
There are many goals, the 20Mg(p,p)20Mg reaction
will be used to scan the states coupled to the 20Mg(0+) state while the 20Mg(p,p’)20Mg
will investigate the states coupled to the 20Mg(2+) core. Recoil protons from the target
will give information on the excitation function of the compound nucleus and the total
path of the beam and fragment will be used to select the inelastic channel. Spectroscopic
properties of the low-lying states will be obtained in a R-matrix analysis of the excitation
Recoil protons E and θ -> Excitation function of the compound nucleus.. Total path -> Select the inelastic channel and contamination.
• The location of the 1/2+ state differs between the models
• The ground state 5/2+ would be seen if closer to J. Holt’s predictions
• Narrow resonances are expected above the 20Mg(2+) threshold function for a given angular range.

28. Thanks for your attention !
Summary and outlook
The future of ISOLDE is bright. It will restart in June 2014 with the low energy program.
With more than 40 year of operation ISOLDE remains as the pioneer ISOL-installation both at the level of designing new devices and production of frontier Physics.
Post accelerated beams up to 5.5 MeV/u for the wide range of nuclei produced at ISOLDE will be available from Autumn 2015.
HIE-ISOLDE will be the only next-generation radioactive beam facility (as identified by the NuPECC LRP) available in Europe in 2015, and the most advanced ISOL facility world-wide.
Welcome to propose challenging experiments!
Thanks for your attention !