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High-Precision Mass Measurements on Exotic Nuclides: Recent Results from ISOLTRAP Experiment

This seminar discusses recent experimental results and new techniques in high-precision mass measurements of exotic nuclides using the ISOLTRAP experiment.

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High-Precision Mass Measurements on Exotic Nuclides: Recent Results from ISOLTRAP Experiment

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  1. EP Seminar, CERN, May 15, 2006 High-precision mass measurements on exotic nuclides: recent results from the ISOLTRAP experiment Alexander Herlert CERN, PH-IS

  2. EP Seminar, CERN, May 15, 2006 High-precision mass measurements on exotic nuclides: recent results from the ISOLTRAP experiment Atomic masses of radionuclides The ISOLTRAP experiment Principle of mass measurement Recent experimental results New techniques and methods

  3. 11Li Hot cycle Cold cycle Common ) g b + , p ( ) ) g g b b + + , , p p ( ( Astrophysics nuclear synthesis r- and rp-process Weak Interaction symmetry tests CVC hypothesis Nuclear Physics nuclear binding energies, Q-values shell closures, pairing, deformation, halos, isomers test of nuclear models and formulae dm/m  1·10-7 dm/m  1·10-8 dm/m  1·10-7 Radionuclides - What accuracy is needed?

  4. Atomic Mass Evaluation 2003 In total: 3180 nuclides Measured masses: 2228 Proton Number Z all nuclides Neutron Number N G. Audi, A.H. Wapstra, C. Thibault, Nucl. Phys. A 729

  5. Atomic Mass Evaluation 2003 In total: 1158 nuclides Proton Number Z dm/m < 10-7 Neutron Number N G. Audi, A.H. Wapstra, C. Thibault, Nucl. Phys. A 729

  6. Atomic Mass Evaluation 2003 In total: 181 nuclides Proton Number Z dm/m < 10-8 Neutron Number N G. Audi, A.H. Wapstra, C. Thibault, Nucl. Phys. A 729

  7. Atomic Mass Evaluation 2003 In total: 24 nuclides Proton Number Z 133,134Cs 85,87Rb dm/m < 10-9 Neutron Number N G. Audi, A.H. Wapstra, C. Thibault, Nucl. Phys. A 729

  8. See: Lunney, Pearson & Thibault, Rev. Mod. Phys. 75 (2003) Mass measurement programs for radionuclides worldwide

  9. JYFL TRAP SMILETRAP  Jyväskylä Stockholm  TITAN SHIPTRAP HITRAP LEBIT GSI  TRIUMF  Munich RIKEN TRAP CERN   MSU Argonne LBL MAFF TRAP ISOLTRAP REXTRAP ATHENA ATRAP WITCH CPT RETRAP Penning traps at accelerators  operating facilities  facilities under construction or test  planned facilities

  10. Production of radioactive nuclides at ISOLDE

  11. Production of radioactive nuclides at ISOLDE

  12. precision trap preparation trap buncher ISOLTRAP: Experimental setup 2m

  13. determination of cyclotron frequency (R = 107) 2 m removal of contaminant ions (R = 105) Bunching of the continuous beam ISOLTRAP: Experimental setup B = 5.9 T B = 4.7 T G. Bollen, et al., NIM A 368, 675 (1996) F. Herfurth, et al., NIM A 469, 264 (2001)

  14. B + q/m Superposition of strong homogeneous magnetic field weak electrostatic quadrupole field Principle of mass determination measurement of cyclotron frequency

  15. B + q/m Principle of mass determination measurement of cyclotron frequency motional modes of ion stored in a Penning trap

  16. Conversion of magnetron into cyclotron motion Scan QP-excitation freq. nrf about nc Magnetron excitation Quadrupole excitationnrf radial  axial energy z MCP Detector passing B-field gradient after ejection Time-of-flight (TOF) Trap B Principle of mass determination

  17. Principle of mass determination mean TOF TOF spectrum Example: 85Rb (900ms excitation duration)

  18. Principle of mass determination mean TOF TOF spectrum fit of theoretical line shape to the data Example: 85Rb (900ms excitation duration)

  19. Principle of mass determination cyclotron frequency of well-known nuclide cyclotron frequency of "unknown" nuclide determination of mass ratio

  20. 133Cs 39K 23Na 85Rb Stable alkali ions as mass references

  21. C4 C11 C12 C10 C3 C9 C2 C8 C7 C6 C18 C19 C5 C17 C4 C16 C15 C14 C22 C13 C21 C12 C20 C11 C19 C18 Carbon clusters as mass references C1 K. Blaum et al., EPJ A 15, 245 (2002)

  22. Determination of the mass accuracy Combined carbon cluster cross-reference measurements dm/m / 10-8 m / u Relative mass accuracy limit: (dm/m)lim= 810-9 A. Kellerbauer et al., EPJ D 22, 53 (2003)

  23. ISOLTRAP mass measurements in 2004-2005 Nuclides measured in 2004/2005 127,128,131-134Sn 126Xe, 136Xe 118,120,122-124Cd 84Kr, 86-95Kr Highlights Nuclide Half-life Uncertainty 22Mg 71-81Zn 17Ne 109 ms 530 eV 35-38K, 43-46K 3.86 s 270 eV 22Mg 21-22Na 178 ms 530 eV 35K 17Ne, 19Ne 290 ms 3.45 keV 81Zn

  24. Nucleosynthesis and r-process Pb s-process protons r-process Sn Ni 82 50 fusion in stars neutrons courtesy: K. Blaum

  25. ISOLDE target for Zn run quartz transfer line UCx target RILIS protons courtesy: T. Stora et al.

  26. Yields at ISOLTRAP estimate for target/ion source 0.5%

  27. Result for 81Zn 81Zn+

  28. Preliminary result for mass excess Zn preliminary Zn m = A·mu + ME

  29. 2n separation energy AME2003 Zn

  30. 2n separation energy AME2003 ISOLTRAP Zn

  31. 131Sn isomer AME2003 G. Audi et al.

  32. Removal of contaminants for Sn measurements Sn Sn34S isobaric contaminants (Cs) Sn34S 127,128,131-134Sn

  33. Preliminary result for mass excess Sn preliminary 131Sn ??? preliminary M. Dworschak et al.

  34. The mass of 17Ne • lightest nuclide measured at ISOLTRAP • two-proton halo candidate: • A. Ozawa et al., Phys. Lett B 334, 18 (1994) • M.V. Zhukov et al., PRC 52, 3505 (1995) • R. Kanungo et al., Phys. Lett. B 571, 21 (2003)

  35. The mass of 17Ne m = A·mu + ME AME2003 17Ne+ 17Ne dm < 600 eV T1/2 = 109 ms YieldISOLDE = 1000/s About 450 ions/h at ISOLTRAP

  36. The two-proton halo candidate 17Ne 17Ne Via the nuclear charge radii! Isotope-shift measurements: (COLLAPS experiment, Neugart et al.) Mass uncertainty of dm /m 1·10-7 (~ 2 keV) required! nuclear charge radii How to probe if 17Ne is a proton halo?

  37. Preliminary result without new mass values Collaps upper limit Collaps lower limit Finite range Droplet PhD thesis W. Geithner

  38. Fermi 0+ 0+b-decays between analog states of spin Jp=0+ and isospin T=1 conserved vector current hypothesis: ft = const MVFermi-matrix element radiative corrections dR and DR isospin not exact symmetry: isospin-symmetry-breaking correction dC Conserved vector current (CVC) hypothesis GV coupling constant for semileptonic weak interaction J.C. Hardy and I.S. Towner, Phys. Rev. C 71, 055501 (2005)

  39. Superallowed b-decay nuclides - 9 best known cases experimental data needed: Q f = f (Z,Q) statistical rate function BR, t1/2 t = f (BR,t1/2) partial half-life 54Co 50Mn 42Sc 46V 34Cl 38mK Tz = -1 14O Tz = 0 26mAl 10C J.C. Hardy and I.S. Towner, Phys. Rev. C 71, 055501 (2005)

  40. Superallowed b-decay nuclides - 9 best known cases 3072.2(8) s I.S. Towner and J.C. Hardy, Phys. Rev. C 66, 035501 (2002)

  41. Vub 0.001% Vus 5% Vud 95% Unitarity of CKM matrix Cabibbo-Kobayashi-Maskawa (CKM) matrix Contribution to the unitarity: Unitarity weak interaction coupling constant GF from muon decay

  42. Unitarity of CKM matrix Result: discrepancy by more than 2s Further experimental data as well as refined calculations of correction terms needed I.S. Towner and J.C. Hardy, Phys. Rev. C 66, 035501 (2002)

  43. The mass of 22Mg • 10 frequency ratios measured • 16 relations included in c2 adjustment 22Mg+ M. Mukherjee et al., Phys. Rev. Lett. 93, 150801 (2004).

  44. Solving the mass discrepancy of 22Mg CPT J. Clark et al. 200 eV M. Mukherjee et al., Phys. Rev. Lett. 93, 150801 (2004).

  45. Updated values 3072.7(8) s J.C. Hardy and I.S. Towner, Phys. Rev. C 71, 055501 (2005) F. Herfurth et al., EPJA 15, 17 (2002) A. Kellerbauer et al., PRL 93, 072502 (2004) M. Mukherjee et al., PRL 93, 150801 (2004)

  46. Updated values for CKM unitarity test new result for Vus: (Brookhaven E865) Vus (K+-decay) = 0.2272(30) (Fermilab E832) Vus (K+-decay) = 0.2252(22) 0.9993  0.0011 Present status: Vud (nuclear b-decay) = 0.9738(4) Vus (kaon-decay) = 0.2200(26) Vub (B meson decay) = 0.00367(47) (non-)unitarity of CKM-matrix i.e. CKM not unitary at the 98% confidence level J.C. Hardy and I.S. Towner, Phys. Rev. C 71, 055501 (2005)

  47. Outlook for CKM unitarity test Tz = 0 extend investigation to other nuclides Tz = -1 increase precision on nine best ft-values

  48. Outlook for CKM unitarity test J.C. Hardy and I.S. Towner, Phys. Rev. C (2005)

  49. New experimental methods and technical development How to improve ISOLTRAP ?

  50. New ion sources Pierre Delahaye new ion source

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