1. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 Advanced charge state breeding Objectives: To optimize the charge breeding process by increasing the breeding efficiency, improving the beam quality and the beam purity. Investigation of charge breeding process and breeding of intense primary beams. Issues to be addressed: * Injection into the high charge state ion source (Continuous or pulsed, emittance matching) * Breeding and cooling of highly charges ions (manipulation of abundance in a single charge state) * Extraction and separation of n+ ions (beam emittance, molecule break up, decay products)

2. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 Mass analyzer Charge breeding device Low energetic 1 + ions Low energetic q + ions Post accelerator or experiment Analyzing magnet Buffer gas emittance cooler Switch yard Isotopes from 1+ ion source Beam preparation and injection Extraction and beam purification Charge state development Charge state breeder setup

3. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 Available setups ISOLDE / CERN /REXTRAP – REXEBIS combination DaresburyPHOENIX test bench at ISOLDE LPSCGrenoble1+  n+ test beam line GSI / LMU MünchenMAXEBIS (Frankfurt) MPI-K Heidelberg Heidelberg EBIT INFN-BariBRIC charge state breeder Charge state breeder outside Europe: * TRIUMF: PHOENIX ECRIS Booster (Canada)TITAN EBIT (Penning trap mass measurements) * ANL (USA):ECRIS charge state breeder (CARIBU project) * MSU (USA):EBIT base charge state breeder for post acceleration project (in design state) * KEK (Japan):ECRIS charge state breeder

4. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 EBIS charge breeders survey REX-ISOLDE Plasma Surface Laser 25 target materials F. Wenander et al. * Element ‘independent’ efficiency * 2.5 < A/q < 4.5 - Poor injection => longer breeding time and lower efficiency

5. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 The constant “quest” for efficiency * Sometimes lower efficiency for radioactive elements scaling problematic / no time for tuning not visible intensities * Have to speak about time efficiency as well! * 50% lost in trap => >26% in EBIS * Global efficiency for EBIS close to 100% Halo nuclei 11 Li + From 6 Li to 238 U with total efficiencies of at least 4% + 11 Li (T 1/2 =8.5 ms) charge bred to 2+ and 3+ with t breed of 5 and 9 ms - Light ions (A<10) still difficult to breed ≤5% total efficiency - Problems with He+ charge exchange processes in REXTRAP

6. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 ECRIS charge breeders survey IS397 Experiment at ISOLDE and experiments at LPSC Injection of molecules: 13 C 16 O  13 C 4+ 0.5% 139 LO +  139 L 23+ 2.5 % Preliminary tests in Afterglow mode: 86 K 13+  86 K 13+ 1% 132 Xe 18+  132 Xe 18+ 2.2% 85 Rb 1+  85 Rb 15+ 2.5 % Trapping and breeding of daughter nuclides (qualitative results):Injection of 61 Mn T 1/2 = 670 ms decays to 61 Fe T 1/2 = 5.98 min Efficiencies Decreasing with A/Q P. Delahaye, T. Lamy et al.

7. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 EBIS potential settings and ion energy for continuous injection * Efficiency (REXEBIS) K 9+ 4% for t breed =9.5 ms * Total efficiency for K 10+ in pulsed mode at this moment >7.5% * CSD one peak lower EBIS efficiency vs extracted charge state EBIS  accu mode * Using EBIS capacity instead of cooler storage capacity * Short-lived ions (<20 ms) cw injection / pulsed extraction

8. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 ECRIS charge breeders pulsed LPSC ECR charge breeding time Steady state Ar 9+ : 5 ms Preglow Afterglow 18 GHz, 950 W 28 GHz, 3600 W Steady states reached at 3 ms for all charges !! T. Thuillier et al., ICIS’07 In ECR Charge state increase can be very fast ! -> But trapping very long ! RF Power RB1+ injection Rb 15+ Afterglow Here 520 ms for Rb 15+ N. Chauvin et al., Nucl. Instrum. Meth. A, Vol 419, nb. 1, 1998 Charge breeding time is a result of the ECRIS compromise, RF, B, Gas

9. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 Shift of the charge state spectra to higher charge states * In Bari  rf-excitation (BRIC) * MAXEBIS  reduced barrier * Uni Frankfurt  fast variation of electron beam current Can be done by fast removal of hot low charged ions  cooling effect

10. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 Charge state manipulation methods?  Using atomic shell structure: Beneficial only for heavy ions until now (REXEBIS)  Very high abundance in on charge states in EBIT, but at the expense of low efficiency  Using DR resonances: In principle possible (shown at Heidelberg EBIT), but efficiency spoiled by energy spread of the electron beam.  Cooling of highly charged ions: Works for medium heavy and heavy elements  survey required

11. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 Simulation tool: CBSIM Included so far: Collision physics: Stepwise ionisation,charge exchange, RR Collision and trap physics: electron-ion-heating,ion-ion cooling Without charge exchange and recombination, but ion losses With charge exchange and recombination Included so far: Trap physics: space charge neutralisation and ion losses Soon: atomic data tables

12. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 TOF out of the REXTRAP for stable SeCO beam injected * Molecular sideband beams from ISOLDE to avoid isobaric contamination * e.g. 70 SeCO to avoid 70 Ge * Keep molecules inside trap, break them in EBIS (or break inside trap with different trap potential settings) Results * ~50% SeCO out of trap * 6.5% SeCO + to Se 19+ in EBIS (58 ms breeding time) * Problems inside the EBIS: ions with high electro-negative values escape the electron beam * Also tried SrF, BaF, AlF (>16% total efficiency for Al7+) Molecule breakup (EBIS)

13. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 Molecule breakup (ECRIS) 139 LaO + molecule breakup up to 2.7% for 139 La 23+ A/q=6.04 + 0,1 + 23 + 420 nA injected Background subtracted Injection of molecules: 13 CO +  13 C 4+ 0.5% 139 LO +  139 L 23+ 2.5 %

14. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 Can the charge breeding with the ECR give access to more beams ? Not directly produced  - decay  + EC decays -- Trapping of daughter nuclides

15. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 61 Mn trapping and ejection Measurement cycle: 1.RF on, plasma ignited 2. 61 Mn injected into the ECR 3.RF is kept on for a time that can be varied (0s, 800ms…) 4.Ejection of the ions as a pulse 0.71s 5.98m 1.65h From TOI, R.B. Firestone Gamma spectrum, 800ms trapping, 61 Mn 12+ and 61 Fe 12+ extracted Fe Mn Fe Mn Fe Energy (keV) cnts

16. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 E. Beebe et al. RHIC test EBIS setup

17. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 Pepperpot Analysis of a 87kV*q Ar-beam Ar spectra  max at Ar 4+ 70kV platform voltage ~17kV trap contribution rms emittance  0.25 mm mrad Shot to shot output: Profiles (left) Horz. and Vert. emittances (below)

18. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 Emittance measurements ECRIS Two 1+ and two n+ identical emittancemeters are setup in the beam Line of LPSC and are working  RMS emittances absolute (20 kV*q) Xplane: 84 Kr 15+ Y plane: 84 Kr 15+ Xplane: 84 Kr 1+ Y plane: 84 Kr 1+ norm. ~0.015 mm mrad norm ~0.06 mm mrad

19. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 Variable pulse length from EBIS * Normal extraction ~90% of the beam within 80  s * Longer beam pulse desirable for experiments (dead-time in DAQ) * Normal extraction ~90% of the beam within 80  s * Longer beam pulse desirable for experiments (dead-time in DAQ) 25us FWHM Extracted pulse structure from EBIS Slow extraction : TOF spectrum of accelerated beam in the Miniball gamma array 200 us FWHM t (us) -> Same breeding efficiency as for normal extraction -> Fairly easy to tune, setup time <2 h (need TOF from experiment for tuning) -> Same breeding efficiency as for normal extraction -> Fairly easy to tune, setup time <2 h (need TOF from experiment for tuning) Beam pulse can be extended from 50 us to >400us FWHM using a different extraction scheme

20. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 FC/scanner1 FC/scanner2 lens steerer FC/scanner3 tape station detectors ECRIS 102 o doubly focusing magnet GPS switchyard A Ar + 2A Kr 2+ 3A Xe 3+ q norm A Ar n+ 2A Kr 2n+ 3A Xe 3n+ 2A Kr 2n+ A Ar n+ 3A Xe 3n+ 1 m before the ECRIS after the ECRIS after the 102 o magnet q norm L. Weismann, J. Cederkäll et al., q norm Beam purification by charge breeding

21. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 Conclusions and outlook * Efficiency survey for EBIS and ECRIS: > 4% for all isotopes, max. 18% for EBIS – cooler combination with optimized cooler: efficiencies > 30% become possible for EBIS * Pulsed and continuous schemes are investigated for both breeder setups * ECRIS breeding times are faster than assumed  trapping time is the restriction! * Molecule break-up, breeding of isotope cocktails and using daughter nuclei of decay in the ion source plasma -> development new beams * Emittance investigations of breeder for intense primary beams * Manipulation of charge state distribution in principle possible, but less boost of efficiency than expected

22. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007

23. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 Slit-foil scanner Pepper pot scanner Emittance scanner used

24. Oliver Kester I3 EURONS EURONS, EURISOL-DS Town Meeting, Helsinki, Finland, Sept. 2007 He 2+ -beam, 130 keV, created by a 6 A / 13 keV electron beam rms beam emittance > 0.3 mm mrad  He 2+ can be created, even if the ions do not stay all the time in the electron beam (larger beam radius) He 2+ -beam, 130 keV, created by a 6 A / 13 keV electron beam rms beam emittance > 0.3 mm mrad  He 2+ can be created, even if the ions do not stay all the time in the electron beam (larger beam radius) Emittance measurements with He-beam