1 stephan ettenauer for the TITAN collaboration The Mass of 74 Rb: First Mass Measurements of Highly Charged, Short- lived Nuclides in a Penning Trap ISAC Science Forum, Feb. 8th, 2011 S966

2 V ud measurements  superallowed 0 + → 0 + decays most precise way to extract V ud f … phase space integral (dep. on Q-value) t … „partial halflife“ (dep on. BR and T ½ ) K … numerical constant J. Hardy, CIPANP 2009 CVC hypothesis

3 The case of 74 Rb P. Finlay et al., PRL 106, (2011) J. C. Hardy and I. S. Towner PRC 79, (2009)

4 Radial overlap correction δ C2 I. S. Towner and J. C. Hardy, PRC 77, (2008) I. S. Towner and J. C. Hardy, PRC 66, (2002) extrapolated from stables→ uncertainty? combined Δ of: charge radius effective interaction procedure 20 % recent Laser Spec. at TRIUMF (S1148)

5  c : comparisons between models T&H (2005) ↔ O&B T&H (2008) ↔ Perturbation theoryT&H (2008) ↔ RPA T&H: WS (2008)  ↔ HF (2009) J.C. Hardy and I.S. Towner, PRC66, (2002 ), PRC71, (2005) W. E. Ormond and B. A. Brown, PRC 52, 2455 (1995), Nucl. Phys. A 440, 274 (1985) J. C. Hardy & I.S. Towner, PRC C77, (2008), PRC C 79, (2009) N. Auerbach, Phys. Rev. C 79, (2009) H. Liang et al., Phys. Rev. C, (2009)

6 “Tests” of Models (assumes CVC) I. S. Towner* and J. C. Hardy, PRC 82, (2010) G.F. Grinyer, C.E. Svensson, B.A. Brown, NIM A 622, 236 (2010) χ 2 minimization theory “experiment” extrapolate to charge-independent limit ∝ Z 2 subtract non Z 2 components from models

7 Q-value for 74 Rb A. Piechaczek et al., PRC 67, (R) (2003) super- allowed direct mass measuremnts in Penning trap: highest precision CERN A. Kellerbauer et al., PRL 93, (2004) PRC 76, (2007) limitation due to T 1/2 to improve precision further: HCI TITAN only online facility to use HCI

8 TITAN 1$CAN Bradbury-Nielsen

9 Electron Beam Ion Trap (EBIT) confinement: –axial by electrostatic field –radial by electron beam + B- field B-field (up to 6 T) compresses e - beam  e - density up to A/cm 2  increased ionization rate requirements for charge breeding: efficient fast

10 TITAN’s EBIT A + (~ 2 keV) Magnet / Trap Electron gun Electron 4 T, as close as 10 cm from the trap center trap electrode X-ray spectroscopy: diagnostics tool for charge breeding EC-BR measurement A +q LEGe X-ray detector E-beam energy: ~ 7 keV E-beam current: ~50 mA T. Brunner et al., NIM B 266, 4643 (2008) S. Ettenauer et al., AIP Conf. Proc. 1182(2009)100

11 Charge Breeding of 75 Rb EBIT MCP TOF path charge bred residual gas preliminary

12 charge state VS breeding time preliminary

13 76 Rb very first mass measurement of radioactive HCIs stat. uncertainty of < 300 eV achieved in a few hours preliminary

14 Ramsey excitation & 75 Rb Ramsey excitation: 2 excitation pulses improves precision by a factor preliminary TITAN 2010 ISOLTRAP HCI during this beamtime demonstrated up to q=12+ compared to conventional method: improvement by factor >24

15 A=74: 74 Ga & 74 Rb TITAN 2010 ISOLTRAP 74 Rb 74 Ga preliminary Dipole Cleaning & Separator Tuning

16 Results 74 Rb 74 Rb: Yield: around 2000/s + contamination from 74 Ga precision already comparable to ISOLTRAP (2007) BUT data of < 20 hours power outage during 74 Rb => reconditioning of EBIT => lower eff. => “easy” improvement next time preliminary σ stat ≈ 4.1 keV

17 HCI and Isomers 78m Rb 78 Rb keV q=8+ & T rf = 197 msq=1+ & T rf = 997 ms Calculation: Measurement: preliminary

18 with yields > 2000 ions/s HCI feasible precision improved by factor q OR same precision q times faster resolving power => close lying isomers measured mass of 78,76,75,74 Rb and 74 Ga precision of 74 Rb possibly sufficient already to have science impact 18 Implications & Conclusions 85 Rb+ 17 e-beam: 14 mA breeding time: 197 ms T rf = 97 ms

19 TITAN collaboration ❖ The TITAN Group ❖ The TITAN Group: Jens Dilling, Paul Delheij, Gerald Gwinner, Melvin Good, Alain Lapierre, David Lunney, Mathew Pearson, Ryan Ringle, Corina Andreoiu, Maxime Brodeur, Alexander Grossheim, Ernesto Mané, Brad Schultz, Martin C. Simon, Thomas Brunner, Usman Chowdhury, Benjamin Eberhart, Stephan Ettenauer, Aaron Gallant, Vanessa Simon, Mathew Smith CNRS- CSNSM ❖ TRIUMF Staff ❖ TRIUMF Staff: Pierre Bricault, Ames Friedhelm, Jens Lassen, Marik Dombsky, Peter Kunz, Rolf Kietel, Don Dale, Hubert Hui, Kevin Langton, Mike McDonald, Raymond Dubé, Tim Stanford, Stuart Austin, Zlatko Bjelic, Daniel Rowbotham, Daryl Bishop And the rest of the TITAN collaboration....