PI ‐ ICR technique for high ‐ precision measurements of nuclide masses (development at SHIPTRAP) Sergey Eliseev K. Blaum, M. Block, S. Chenmarev, A. Dörr, C. Droese, T. Eronen, P. Filjanin, M. Goncharov, M. Höcker, J. Ketter, E. Minaya Ramirez, D. Nesterenko, Yu. Novikov, L. Schweikhard, V. Simon GSI Helmholtzzentrum für Schwerionenforschung GmbH, Germany Max ‐ Planck ‐ Institut für Kernphysik, Germany Institut für Physik, Ernst ‐ Moritz ‐ Arndt ‐ Universität,Germany Petersburg Nuclear Physics Institute, Russia NUSTAR Meeting, March 5 th
high ‐ precision measurements of masses of exotic nuclides δ m/m Examples Field shell closures, shell quenching, regions of nuclear structure deformation, drip lines, halos, island of stability physics 10 ‐ 6 ‐ 10 ‐ 7 rp ‐ process and r ‐ process path, waiting ‐ points nuclei, astrophysical reaction rates, neutron stars astrophysics CVC hypothesis, CKM matrix unitarity, Ft of weak interaction 10 ‐ 8 studies superallowed ß ‐ emitters metrology, α (h/m Cs , m Cs /m p , m p /m e ), m Si fundamental const. 10 ‐ 9 ‐ 10 ‐ 10 neutrino physics 0 νββ , 0 ν 2EC neutrino mass β - decay, EC CPT tests <10 ‐ 11 m p and m p m e- and m e+ QED in m ion , electron binding energy highly ‐ charged ions
high ‐ precision measurements of masses of exotic nuclides δ m/m Examples Field shell closures, shell quenching, regions of nuclear structure deformation, drip lines, halos, island of stability physics 10 ‐ 6 ‐ 10 ‐ 7 rp ‐ process and r ‐ process path, waiting ‐ points nuclei, astrophysical reaction rates, neutron stars astrophysics CVC hypothesis, CKM matrix unitarity, Ft of weak interaction 10 ‐ 8 studies superallowed ß ‐ emitters metrology, α (h/m Cs , m Cs /m p , m p /m e ), m Si fundamental const. 10 ‐ 9 ‐ 10 ‐ 10 neutrino physics 0 νββ , 0 ν 2EC neutrino mass β - decay, EC CPT tests <10 ‐ 11 m p and m p m e- and m e+ QED in m ion , electron binding energy highly ‐ charged ions
Penning trap the most accurate mass spectrometer strong uniform static B ‐ field B q / m 1 q ν c ν c = 2 π m m B
Penning trap the most accurate mass spectrometer strong uniform SHIPTRAP THe ‐ TRAP static B ‐ field Max ‐ Planck Institute for Nuclear Physics, JYFLTRAP Heidelberg TRIGATRAP Δ B < 10 -11 h -1 MLLTRAP B B Δ B < 5 · 10 -9 h -1 B q / m 1 q ν c ν c = 2 π m m B
Penning trap the most accurate mass spectrometer uniform B ‐ field quadrupole E ‐ field Penning Trap B + = q / m ν + ν + - modified cyclotron ν - ν q 1 ν c ν - - magnetron m B ν z c = 2 π m ν z - axial Δ ν ν c = ν + + ν 10 − > 10 c − ν c
Penning ‐ Traps worldwide JYFLTRAP SHIPTRAP MLLTRAP TITAN TRIGATRAP LEBIT CPT ISOLTRAP FSU on-line facility for short-lived nuclides δ m/m ~ 10 -6 - 10 -8 ultra-precise Penning trap for long-lived and stable nuclides δ m/m <10 -10
Penning ‐ Traps worldwide JYFLTRAP SHIPTRAP MLLTRAP TITAN TRIGATRAP LEBIT CPT ISOLTRAP on ‐ line facilities (short ‐ lived nuclides) δ m/m ~ 10 ‐ 6 ‐ 10 ‐ 8 until now future ? ToF ‐ ICR technique PI ‐ ICR technique
Penning ‐ Traps worldwide JYFLTRAP SHIPTRAP MLLTRAP TITAN TRIGATRAP LEBIT CPT ISOLTRAP on ‐ line facilities (short ‐ lived nuclides) δ m/m ~ 10 ‐ 6 ‐ 10 ‐ 8 until now future ? ToF ‐ ICR technique PI ‐ ICR technique
SHIPTRAP 150 ‐ 1000 keV/u ≈ 1 eV gas ‐ filled RF ‐ quadrupole Penning traps stopping chamber (cooler & buncher) reaction products From SHIP superconducting magnet MCP ‐ detector preparation measurement trap trap M. Block et al., Eur. Phys. J. D 45 (2007) 39
Currently used ToF-ICR technique ( T ime- o f- F light I on- C yclotron- R esonance) � � ∂ � B = − μ ⋅ F ∂ z larger μ → shorter ToF
Currently used ToF-ICR technique ( T ime- o f- F light I on- C yclotron- R esonance) � � ∂ � B = − μ ⋅ F ∂ z larger μ → shorter ToF injection
Currently used ToF-ICR technique ( T ime- o f- F light I on- C yclotron- R esonance) � � ∂ � B = − μ ⋅ F ∂ z larger μ → shorter ToF excitation of ν − injection -U 0 cos( ω - t) μ∼ r 2 ν − U 0 cos( ω - t)
Currently used ToF-ICR technique ( T ime- o f- F light I on- C yclotron- R esonance) � � ∂ � B = − μ ⋅ F ∂ z larger μ → shorter ToF π − pulse at ν rf ≈ ν c excitation of ν − injection -U 0 cos( ω rf t) -U 0 cos( ω - t) U 0 cos( ω rf t) μ∼ r 2 ν − μ∼ r 2 ν + -U 0 cos( ω rf t) U 0 cos( ω - t) U 0 cos( ω rf t)
Currently used ToF-ICR technique ( T ime- o f- F light I on- C yclotron- R esonance) � � ∂ � B = − μ ⋅ F ∂ z larger μ → shorter ToF π − pulse at ν rf ≈ ν c excitation of ν − injection ejection -U 0 cos( ω rf t) -U 0 cos( ω - t) U 0 cos( ω rf t) time of flight μ∼ r 2 ν − μ∼ r 2 ν + -U 0 cos( ω rf t) U 0 cos( ω - t) U 0 cos( ω rf t) ν c
Nuclear Chart
Nuclear Chart we want to measure masses of nuclides with T 1/2 ~100 ms with a few keV accuracy ( δ m/m~10 -8 ) be able to resolve isomeric states with a few ten keV energy
Perfomance of ToF-ICR technique ν = ⋅ ν ⋅ τ c 1 . 6 Δ r= HWHM Δ ν c singly charged ions of M=200 r c ν c ≈ 500 kHz Δ 1 . 6 r δν ≈ N =1000 c τ r N uncertainty resolving power trapping time trapping time
new technique for singly ‐ charged ions • gain in resolving power: ~ 50 • much faster measurements • gain in precision: ~ 5
determination of neutrino mass with accuracy of 0.2 eV EC in 163 Ho ‐ Project Analysis β — decay of 187 Re δ Q ~ 1 eV ( δ Q/m < 10 ‐ 11 ) neutrino-mass value (PENTATRAP) δ Q ~ 50 eV ( δ Q/m < 3 ∙ 10 ‐ 10 ) development of experiment
Development of the ECHo ‐ Project (scale of experiment) 163 Ho 163 Ho 187 187 Re Re SHIPTRAP in 2014-2015 Measurement of Q ‐ values of 187 Re β ‐ decay & EC in 163 Ho with 50 eV ‐ uncertainty
New PI-ICR technique ( P hase- I maging I on- C yclotron- R esonance) ν c = ν + + ν − B
New PI-ICR technique ( P hase- I maging I on- C yclotron- R esonance) ν c = ν + + ν − B
φ + π φ + π 2 n 2 n ν = − − ν = + + − + π π 2 t 2 t − + ν c = ν + + ν −
Penning trap position-sensitive detector B
delayline position position- -sensitive sensitive detector detector RoentDek RoentDek GmbH DLD40 GmbH DLD40 delayline Active diameter 42 mm 25 μ m Channel diameter Open area ratio >50 % 70 μ m � Position resolution Max. B-field a few mT � Time resolution ~ 10 ns
ν c = ν + + ν measurement of free cyclotron frequency: − magnetron frequency ν - modified cyclotron frequency ν + center (stable over days) (nuclide-independent) mag.reference phase - + (stable over days) cyc.reference phase (stable over days) mag. final phase cyc. final phase
ν c = ν + + ν measurement of free cyclotron frequency: − magnetron frequency ν - modified cyclotron frequency ν + center (stable over days) (nuclide-independent) mag.reference phase - + (stable over days) cyc.reference phase (stable over days) mag. final phase cyc. final phase if production rates of exotic nuclides are extremely low and experiment time is limited? it is desirable to skip the measurement of the reference phases
ν c = ν + + ν measurement of free cyclotron frequency: − magnetron frequency ν - modified cyclotron frequency ν + center (stable over days) (nuclide-independent) mag.reference phase - + (stable over days) cyc.reference phase (stable over days) mag. final phase cyc. final phase free cyclotron frequency ν c φ + π 2 n ν = c c π c 2 t magnetron phase cyclotron phase
PI-ICR vs. ToF-ICR center magnetron phase cyclotron phase δν ( ) = − = ⋅ π ≅ c ToF ICR gain in precision 1 . 6 5 ! δν ( ) c PI ICR π ⋅ π ⋅ 0 . 6 r 0 . 6 1 = = ≅ gain in resolving power 40 Δ r 0 . 05 higher sensitivit y
PI-ICR vs. ToF-ICR in experiment PI-ICR ToF-ICR 10-hour measurements δ[ M( 124 Xe) - M( 124 Te)] ~ 300 eV δ[ M( 132 Xe) - M( 131 Xe)] ~ 70 eV !!! Gain in Precision ~ 4.5 !!!
PI-ICR in experiment Δ M = M( 132 Xe) - M( 131 Xe) δ(Δ M) SHIPTRAP = (30 stat )( 12 sys ) eV Δ M SHIPTRAP - Δ M reference = (8 ± 35) eV
PI-ICR in experiment Δ M = M( 132 Xe) - M( 131 Xe) first ever measurement of mass difference of singly charged medium-heavy non-mass-doublets with a relative accuracy of 2·10 -10 !!!
SHIPTRAP in 2014-2015 We are preparing for the measurement of the Q -value of: β − -decay of 187 Re (1) EC in 163 Ho (2) with an uncertainty of ~ 50 eV
Summary Summary PI-ICR has been developed at SHIPTRAP for mass • measurements on singly-charged short-lived nuclides PI-ICR is much faster than ToF-ICR and offers very • high mass resolving power • Performance at SHIPTRAP: δ (M( 132 Xe) - M( 131 Xe)) = ± 30 eV • Plans at SHIPTRAP: Q-values of EC in 163 Ho and β -decay of 187 Re
Acknowledgements Acknowledgements Thank you for your attention ! Thank you for your attention !
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