1. Pierre Delahaye CERN - ISOLDE
The Physics requirements for advanced radioactive ion beam manipulation
Pierre Delahaye
CERN - ISOLDE

2. The chart of the nuclides An open landscape for investigations
Nuclear physics
Structure, magic numbers, deformations, haloes, Superheavy elements, nuclear equation of states…
Nuclear Astrophysics
Nucleosynthesis, r and rp processes, supernovae explosions, X ray bursts…
Weak Interaction physics and fundamental symmetries
CVC, CKM Unitarity, Exotic interactions…
Solid State physics
&
Medical Applications!
From the EURISOL report

3. Advanced techniques for the Radioactive ion beam manipulation
The EURISOL project
Beam preparation task
Advanced techniques for the
Radioactive ion beam manipulation
More radioactive beams for more available energies!
Beta-beam aspect

4. Outline of the talk II) A few examples for beam preparation
I) Inventory of devices and techniques
II) A few examples for beam preparation
The low energy stage of REX-ISOLDE post-accelerator
The Collaps experiment at ISOLDE
III) A few examples for precision measurements
The ISOLTRAP penning trap spectrometer
The beta –neutrino angular correlation measurements at LPC Caen, ISOLDE (WITCH) and at Triumf
The 6He charge radius measurement at ANL
The HITRAP project at GSI

5. I - Inventory What devices for what purpose?
A physics experiments usually requires
High intensity
Beam purity
Beam quality (radial and longitudinal emittances)
A rich variety of available beams
A rich variety of accelerated beams
Beam preparation
Also providing powerful tools to precision measurements!

6. A mass separator A mass separator Better … Beam purity
ISOLDE HRS upgrade
Tim Giles CERN AB-OP
R=m/dm~4000 in best cases
Upgrade
R~10,000
Better … Beam purity
High acceptance 100%

7. A charge breeder ECR booster vs EBIS – stripping foils REX-EBIS
Operational at REX-ISOLDE
Phoenix ECRIS
14GHz
Test stand at ISOLDE
Singly charged ions n+ ions transformation
More post-accelerated beams available
More radioactive isotopes available
Better purity in some cases
Some applications for physics experiments of charge bred beams
Efficiency: % in one charge state depending on Z
Molecular sidebands from the ISOLDE targets

8. Ion coolers RFQ coolers vs Penning trap coolers
PhD thesis of Ivan Podadera, CERN
ISCOOL in its commissioning phase
REXTRAP at REX-ISOLDE
Electromagnetic traps filled by buffer gas: damping of the ion motion by collisions
Better beam quality – lower transversal emittance
Possibility of beam bunching: a few µs bunches
Penning trap: the mass selection is a-priori possible | R=105 at ISOLTRAP!
The transmission depends on space charge limits

9. Electromagnetic traps
Penning traps
Paul traps
MOT
6 laser beams
With a magnetic field
An atom trap

10. II - Beam preparation
The 1+  n+ scenario for the Physics with radioactive accelerated beams
The case of REX-ISOLDE
The requirements for charge bred beams
The needs for cooled and bunched beams
The Collaps experiment

11. ISOL and In-flight facilities
ISOLDE, GANIL/SPIRAL, TRIUMF, …
GSI (FAIR project), MSU, ANL…
From the EURISOL report

12. The 1+n+ scenario at ISOL facilities
ECR breeder vs EBIS | stripping foils
Stripping foils requires a pre-accelerator
Usually limited to small A/q
Accelerator
ISOL target
1+ ion source
1+ n+
1+ separator
A/q separator
Studied in the frame of the EURISOL and RIA projects

13. Physics with accelerated beams at REX-ISOLDE
The REX-ISOLDE post accelerator

14. The low energy stage
REXTRAP
REX EBIS
q/A-selector
breeding time (A/q < 4.5) ms beam intensities < 109 /s ions in one charge state < 30% injection efficiency into EBIS >80% efficiency REXTRAP %
Limited by space charge effects above 109 ions/ cycle

15. REXTRAP A longitudinal Penning trap filled with Ne as buffer gas
Superconducting magnet 3T
PNe ~10-4 mbar in the trapping area DE
Buffer gas cooling
Accumulation
Cooling
Ejection

16. Trap Layout P. Schmidt et al, Nucl. Phys. A 701(2002)550 1m
Center electrodes
Injection plate
Ejection plate
Pulse drift tube
Magnet 3T – Trap electrodes
P. Schmidt et al, Nucl. Phys. A 701(2002)550

17. REXEBIS The EBIS superconducting magnet The LaB6 cathode
EBIS specifications
Super conducting solenoid, 2 T
Trap length <0.8 m
Electron beam, <0.3 A and 3-6 keV
Breeding time 3 to >200 ms
<50 ms extracted bunches
Ramped HT potential kV
Warm bore
capacity up to charges

18. The EBIS setup
The charge state is selected with a mass separator of Nier-Spectrometer type
98 ms breeding
Radioactive 110Sn+
9% breeding efficiency in 27+

19. Experiments by REX-ISOLDE
Mainly nuclear spectroscopy experiments
B(E2) measurements with MINIBALL transfer reactions and Coulomb excitations
Miniball cluster
CD detector

20. Coulomb excitation of 70Se
Measurement of the B(E2) of 70Se for validation of the shape coexistence in the mass 70 region
IS397 collaboration D. Jenkins, P.A. Butler
Mass 70: contamination of 70Ge+ from the usual ZrO target
Solution: molecular sidebands from the target 70SeCO
REXEBIS
>5% SeCO+Se19+
>50% efficiency for
SeCO+ cooling
REXTRAP
First run partly successful this year, should be renewed next year

21. Different cooling schemes
Time of flight out of REXTRAP
Molecular break-up V
~120 eV
80 eV X V
SeCO molecule trapping
~30 eV
15 eV X

22. Charge bred beams at ISOLDE?
Solid state physics experiments
Astrophysics experiments
ECRIS + HV platform
Filling the gap between ISOLDE and REX-ISOLDE energies for intense radioactive beams
ISOLTRAP
Mass measurements sensitivity wc=qB/m
REX-ISOLDE:
High intensity radioactive beams?

23. Charge bred beams at ISOLDE
H. Haas AB-Note OP

24. The ECR charge breeder

25. The needs for cooled and bunched beams
Reduction of emittance for mass separators –ISCOOL for the HRS upgrade at ISOLDE
Reduction of emittance and bunching for the EBIS charge breeders – REXTRAP at REX-ISOLDE
Better transport to experiments
time reference, monochromatic beam, better injection control into spectrometers – ISCOOL for Collaps

26. The Collaps case Collinear laser spectroscopy and b-NMR spectroscopy
Measurement of nuclear moments, spin and charge radii of radioactive isotopes

27. Experimental technique
courtesy of K. Flanagan COLLAPS collaboration

28. A RFQ cooler Expected ISCOOL transmission: 100% (less than 100nA)
Radius: a few mm
Bunch time width: a few µs

29. Cold and bunched beams for Collaps
Current limiting factors for laser spectroscopy
Background of scattered laser light detected by PMT ~2000/s.
Detection efficiency within the light collection region.
Broadening of lineshape due to voltage ripples.
Within the light collection region the ion beam should have zero divergence (parallel beam)
Currently the minimum ion beam diameter reached is ~6mm
In order to maximize the detection efficiency good overlap between laser and ion beams is necessary
This results in a high background level from scattered light
K. Flanagan COLLAPS collaboration

30. Cold and bunched beams for Collaps
A reduction in the ion beam diameter will allow the laser to be reduced in diameter (and therefore power) with no detrimental effect on the detection efficiency.
Immediate consequences for the detected background
Bunching ions in the RFQ cooler
Trap and accumulates ions – typically for 300 ms
Releases ions in a 15 µs bunch
Background suppression equal to the ratio of the trapping time to the bunch width 300ms/15 µs ~ 104
K. Flanagan COLLAPS collaboration

31. JYFL experiment
K. Flanagan COLLAPS collaboration

32. III - Precision measurements
The ISOLTRAP penning trap spectrometer
The beta –neutrino angular correlation measurements at LPC Caen, ISOLDE (WITCH) and at Triumf
The 6He charge radius measurement at ANL
The HITRAP project at GSI
Electromagnetic traps as a precision measurement tool

33. The ISOLTRAP mass spectrometer
Carbon cluster ion source
RFQ cooler buncher
Cooling Penning trap
Precision Penning trap
MCP1
MCP3
MCP5
2.8 keV ion bunches
Precision measurement of wc=qB/m
Stable alkali reference ion source
Precision trap
ISOLDE beam
60 keV

34. Ion motion manipulation
TOF vs. excitation frequency
Scan QP-excitation freq. nrf about nc
Magnetron excitation
Quadrupolar excitation nrf
Radial energy  axial energy
Magnetron excitation: r
Cyclotron excitation: r+
TOF resonance
Relative accuracy:
(dm/m) £ 10-7

35. The physical aims The mass as a fundamental quantity for
Reactions (Q values)
Nuclear models
Nuclear Structure (S2n)– shell closure, magic numbers, deformations, IMME…
Astrophysics - waiting points, decay rates
Weak interaction physics - Tests of CVC and the unitarity of the CKM matrix

36. Refinement of the mass surface
S2n=B(N,Z)-B(N-2,Z)
N = 50 shell closure
Deformation

37. Mid-shell effects around N=40
Cu,Ga, Ni isotopic chains measured – Céline Guénault et al, in preparation

38. FT value measurements Superallowed b transitions: 0+ -> 0+
Comparative half-life
corrected ft
Is constant in the CVC hypothesis
dR radiative correction
dC isospin symmetry-breaking correction
DRV nucleus independent radiative correction
f~Q5

39. From Klaus Blaum, NUPAC meeting at ISOLDE 2005/10/11
CVC test
ISOLTRAP mass measurements
22Mg → 22Na : dQ=0.28 keV, 34Ar → 34Cl : dQ=0.41 keV, 74Rb → 74Kr : dQ=4.5 keV
CVC hypothesis confirmed in this mass region
[I.S. Towner & J.C. Hardy, Phys. Rev. C 71, (2005)]
Limit from QEC(38Ca)
62Ga
JYFLTRAP
LEBIT
38Ca
CPT
46V
66As
74Rb
34Ar
22Mg
From Klaus Blaum, NUPAC meeting at ISOLDE 2005/10/11
F. Herfurth et al., Eur. Phys. J. A 15, 17 (2002)
A. Kellerbauer et al., Phys. Rev. Lett.93, (2004)
M. Mukherjee et al., Phys. Rev. Lett. 93, (2004)
T. Eronen et al., to be published (2005)
G. Savard et al., Phys. Rev. Lett. 95, (2005)

40. The b-n angular correlation in nuclear b decay
Test of the V-A theory
Sensitive to exotic interactions S,T
Pure Fermi transitions
Pure Gamow Teller transitions
V-A aF=1
V-A aGT=-1/3
Johnson et al. (1963!)
Adelberger et al. (1999)
32Ar
6He
& if
& if

41. The b-n angular correlation in nuclear b decay
b decay spectrum a
Fermi transition (DJ=0)
Gamow-Teller transition (DJ=0±1)
46V
qer=180°
qer=0°
6He
qer=180°
qer=0°

42. A Paul trap as the center of the detection setup
LPCTRAP collaboration, at GANIL
- Transparent Paul trap, UHV
- Ions confined in the middle of the device, nearly at rest
- In coincidence detection of the electron and the recoil ion
Eb, tstart
tstop
qer
b particle
Recoil ion
Beta telescope
Silicone stripped detector
+ Scintillator
MCP
Delay lines anode
In coincidence measurement of:
the time of flight of the recoil ion tR
the beta particle energy Eb
the angle between these two particles qer
Pierre Delahaye et al., Hyp. Int. 132(2001)479

43. Experimental setup SPIRAL beam LPCTRAP collaboration
RFQ cooler buncher
pulse down
Paul trap
chamber
SPIRAL beam HT
LPCTRAP collaboration
DSSD +
scintillator
20 cm
Monitor
MCP
MCP +
DL anode
"Ring"
trap

44. First TOF spectrum LPCTRAP collaboration, at GANIL
conditioned spectrum
(V-A theory)
Oscar Naviliat, Scientific council of GANIL, June 2005

45. The WITCH retardation spectrometer
The WITCH experiment IKS Leuven at ISOLDE
35Ar decay
Search for scalar interaction
Recoil ion energy spectrum
D. Beck NIM A 503(2003)567

46. The TRINAT experiment at TRIUMF
A MOT as the center of the detection setup
J. Behr et al,
Phys. Rev. Lett. 79, 375
A. Gorelov et al,
Phys. Rev. Lett. 94,
e- shakeoff
From Dan Melconian, PhD, Triumf

47. 6He - Single Atom Spectroscopy
Courtesy of Peter Müller,
Argonne Nat. Lab
6He - Single Atom Spectroscopy
Single atom signal
One 6He atom
6He spectroscopy
~150 6He in 1 hr
6He
7Li3+
60 MeV
6He ATLAS
Graphite
~ 1´106 / s
Photon
counter
Zeeman
slower
MOT
Transverse
cooling
389 nm
1083 nm
Atom Trapping of 6He
6He trapping rate
~ 2 / min
RF -
Discharge Kr
carrier
gas
He*
Spectroscopy 389 nm
2 3S1
1 1S0
2 3P2
3 3P2
Trap 1083 nm
He level scheme

48. 6He - Nuclear Charge Radius
Isotope shift (23S1 - 33P2, 6He – 4He)
(56) MHz
6He rms charge radius
2.054(14) fm (0.7%)
Model independent!
Atomic isotope shift
This work
Experiment
Reaction collision
Tanihata ‘92
Elastic collision
Alkhazov ‘97
Csoto ‘93
Funada ‘94
Cluster models
Varga ‘94
Wurzer ‘97
Theory
Esbensen ‘97
No-core shell model
Navratil ‘01
Quantum MC
Pieper ’05 priv. comm.
L.-B. Wang et al., PRL 93, (2004)

49. The HITRAP Project for Highly Charged Ions GSI Darmstadt
Courtesy of W. Quint and the HITRAP collaboration
UNILAC
experiments with particles at rest or at low energies
cooler
Penning
trap
post-
decelerator
SIS
400 MeV/u
stripper
target
EXPERIMENTS WITH HIGHLY CHARGED IONS AT EXTREMELY LOW ENERGIES:
stable and radioactive isotopes
collisions at very low velocities, surface studies
laser and x-ray spectroscopy
g-factor measurements of the bound electron
fundamental constants
mass measurements of extreme accuracy
polarization of radionuclides, decay spectroscopy of
highly charged radionuclides
U92+
U73+
U92+
ESR
electron cooling and deceleration down to 4 MeV/u

50. Operational Parameters:
HITRAP at the Experimental Storage Ring ESR
Courtesy of W. Quint and the HITRAP collaboration
Precision trap
Operational Parameters:
Deceleration from 4 MeV/u to keV/u
HCI with M/q  3
Beam intensity: some
105 ions/pulse for U92+
Repetition time: 10 s
MAX- EBIS
Other experimental setups (beam line height: 1.25 m)
5 keV*q
Re-injection channel
LEBT
4 main components:
Energy buncher to adapt the bunchlength to the IH requirements – main source of loss (2/3 are lost!)
IH LINAC that will be build by Ratzinger
RFQ -> Schempp plus some elements that keep the beam together
Cooler trap at 4K
NEW: The second harmonic buncher will be there from the start due to interesting offers for the needed amplifiers
NEW: We have to shift the whole setup further downstream to make space for PHELIX
This has been made possible also by shortening the low energy transfer line using electrostatic optics
NEW: Found a scheme how to trap at least 2.5 macrobunches of the ESR in a rather short trap (<0.5 m )
vertical beam line

51. GSI Future Project FAIR: FLAIR - Facility for Low-Energy Antiproton and Ion Research
NESR
Pbar & ions
30 – 400 MeV
LSR:
Standard ring
Min. 300 keV (CRYRING)
USR
Electrostatic
Min 20 keV (MPI KP HD)
HITRAP
Pbars and ions
Stopped & 5 keV
(under construction for ESR)
energy range: 400 MeV – 1 meV

52. Conclusion
Intensive studies of Mass separators, charge breeders and ion coolers for the next generation facilities are going on
Electromagnetic traps are particularly suited for precision experiments
The advanced techniques for radioactive ion beam manipulation: a field in effervescence!
Thank you for your attention!

53. Thanks to my colleagues
REX-ISOLDE
R. Savreux, T. Sieber, F. Wenander, D. Voulot, P. Delahaye and the REX-ISOLDE collaboration
The IS397 collaboration
C. J. Barton, K. Connell,T. Fritioff, O. Kester, T. Lamy, M. Lindroos, M. Marie-Jeanne, P. Sortais, P. Suominen, G. Tranströmer, F. Wenander, P. Delahaye, …
ISOLTRAP
G.Audi, K. Blaum, G. Bollen, D.Beck, C. Guénaut, F. Herfurth, A. Herlert, A. Kellerbauer, H.-J. Kluge, D. Lunney, S. Schwarz, L. Schweikhard, C. Weber, C. Yazidijan , P. Delahaye ..., the ISOLTRAP and ISOLDE collaboration
LPC CAEN (LPCtrap collaboration)
Gilles Ban, Guillaume Darius, Dominique Durand, Xavier Flechard, Mustapha Herbane, Marc Labalme, Etienne Lienard, François Mauger, Alain Mery, Oscar Naviliat, Pierre Delahaye
Gilles Ban, Guillaume Darius, Pierre Delahaye, Dominique Durand, Xavier Flechard, Mustapha Herbane, Marc Labalme, Etienne Lienard, François Mauger, Alain Mery, Oscar Naviliat