Advanced Techniques for Radioactive Ion Beam Manipulation

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

2. The chart of the nuclidesAn open landscape for investigations • In… • 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 http://www.ganil.fr/eurisol/Final_Report.html

3. 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. 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 Outline of the talk

5. 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! I - InventoryWhat devices for what purpose?

6. A mass separator A mass separator 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. ECR booster vs EBIS – stripping foils A charge breeder 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: 1 - 20% in one charge state depending on Z Molecular sidebands from the ISOLDE targets

8. RFQ coolers vs Penning trap coolers Ion 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. Penning traps Paul traps MOT Electromagnetic traps 6 laser beams With a magnetic field An atom trap

10. 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 II - Beam preparation

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

12. The 1+n+ scenarioat 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. The REX-ISOLDE post accelerator Physics with accelerated beams at REX-ISOLDE

14. REX EBIS q/A-selector REXTRAP The low energy stage breeding time (A/q < 4.5) 20 msbeam intensities < 109 /sions in one charge state < 30%injection efficiency into EBIS >80%efficiency REXTRAP 50% Limited by space charge effects above 109 ions/ cycle

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

16. 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

17. 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

18. Charge bred beams at ISOLDE H. Haas AB-Note-2004-034-OP

19. 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 The needs for cooled and bunched beams

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

21. Experimental technique courtesy of K. Flanagan COLLAPS collaboration

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

23. Cold and bunched beams for Collaps R 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

24. 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

25. JYFL experiment K. Flanagan COLLAPS collaboration

26. 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 III - Precision measurements Electromagnetic traps as a precision measurement tool

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

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

29. 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 The physical aims

30. 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

31. LEBIT 38Ca 66As Limit from QEC(38Ca) JYFLTRAP CPT 46V 62Ga CVC test ISOLTRAPmass 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, 055501 (2005)] 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, 072502 (2004) M. Mukherjee et al., Phys. Rev. Lett. 93, 150801 (2004) T. Eronen et al., to be published (2005) G. Savard et al., Phys. Rev. Lett. 95, 102501 (2005)

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

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

34. tstop Eb, tstart • qer 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 detectionof the electron and the recoil ion 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

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

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

37. 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

38. 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, 142501 e- shakeoff From Dan Melconian, PhD, Triumf

39. Courtesy of Peter Müller, Argonne Nat. Lab 6He Production @ ATLAS Single atom signal 6He spectroscopy ~ 1´106 / s One 6He atom Graphite ~150 6He in 1 hr 7Li3+ 60 MeV 389 nm 1083 nm MOT 6He Zeeman slower He* He level scheme 3 3P2 RF - Discharge Spectroscopy389 nm 2 3P2 Trap1083 nm 6Hetrapping rate ~ 2 / min Transverse cooling Kr carrier gas Photon counter 2 3S1 Atom Trapping of 6He 1 1S0 6He - Single Atom Spectroscopy

40. 6He - Nuclear Charge Radius Isotope shift(23S1 - 33P2, 6He – 4He) 43 194.772(56) MHz 6He rms charge radius 2.054(14) fm (0.7%) Modelindependent! 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 Pieper ’05priv. comm. Quantum MC L.-B. Wang et al.,PRL 93, 142501 (2004)

41. The HITRAP Project for Highly Charged IonsGSI Darmstadt stripper target Courtesy of W. Quint and the HITRAP collaboration UNILAC experiments with particles at rest or at low energies cooler Penning trap post- decelerator 400 MeV/u SIS • 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 U73+ U92+ U92+ ESR electron coolingand deceleration down to 4 MeV/u

42. HITRAP at the Experimental Storage Ring ESR Courtesy of W. Quint and the HITRAP collaboration Precisiontrap • 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 verticalbeam line

43. 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 & extracted @ 5 keV (under construction for ESR) GSI Future Project FAIR:FLAIR - Facility for Low-Energy Antiproton and Ion Research energy range: 400 MeV – 1 meV

44. 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! Conclusion Thank you for your attention!

45. 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