Double Penning trap technique for precise g factor determinations in highly charged ions (original) (raw)
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Physical Review Letters, 2000
We present a new experimental value for the magnetic moment of the electron bound in hydrogenlike carbon ͑ 12 C 51 ͒: g exp 2.001 041 596 ͑5͒. This is the most precise determination of an atomic g J factor so far. The experiment was carried out on a single 12 C 51 ion stored in a Penning trap. The high accuracy was made possible by spatially separating the induction of spin flips and the analysis of the spin direction. The current theoretical value amounts to g th 2.001 041 591 ͑7͒. Together experiment and theory test the bound-state QED contributions to the g J factor of a bound electron to a precision of 1%.
European Physical Journal A, 2002
We describe a double-Penning-trap experiment suitable for testing QED in strong fields by determining the electronic g-factor of a single hydrogen-like ion in its ground state. Our measurements on 12 C 5+ reach a relative accuracy of 2 × 10 −9 , where the largest uncertainty results from the mass of the electron. Together with equally precise theoretical predictions therefore, it is possible to evaluate a new value for the electron's mass. The possibilities to obtain other fundamental constants and nuclear parameters are lined out.
Measurement of the g Factor of the Bound Electron in Hydrogen-like Oxygen 16 O 7
Hyperfine Interactions, 2003
The measurement of the g factor of the electron bound in a hydrogen-like ion is a high-accuracy test of the theory of Quantum Electrodynamics (QED) in strong fields. Here we report on the measurement of the g factor of the bound electron in hydrogen-like oxygen 16O7+. In our experiment a single 16O7+ ion is stored in a Penning trap. Quantum jumps between the two spin states (spin up and spin down) are induced by a microwave field at the spin precession frequency of the bound electron. The g factor of the bound electron is obtained by varying the microwave frequency and counting the number of spin flips. Our experimental value for the g factor of the bound electron is g exp(16O7+)=2.000 047 026(4). The theoretical prediction from non-perturbative bound-state QED calculations is g th(16O7+)=2.000 047 0202(6).
The anomalous magnetic moment of the electron in hydrogenlike ions
The European Physical Journal Special Topics, 2008
The precise determination of the anomalous magnetic moment of the electron bound in hydrogen-like ions allows for a stringent test of quantum electrodynamics (QED) in the presence of strong electric fields. g-factor measurements on the electron bound in hydrogen-like ions 12 C 5+ and 16 O 7+ , using single ions confined in a Penning trap, have yielded values in agreement with theory on the ppb level. If the QED calculations are considered correct, the results can in turn be used for a determination of fundamental constants like the electron mass m e, the fine structure constant α or nuclear parameters. We report about present developments towards g-factor measurements also in medium-heavy and heavy highly-charged ions.
Direct Bound-Electron ggg factor Difference Measurement with Coupled Ions
2022
The quantum electrodynamic (QED) description of light-and-matter interaction is one of the most fundamental theories of physics and has been shown to be in excellent agreement with experimental results [1–6]. Specifically, measurements of the electronic magnetic moment (or g factor) of highly charged ions (HCI) in Penning traps can provide a stringent probe for QED, testing the Standard model in the strongest electromagnetic fields [7]. When studying the difference of isotopes, even the intricate effects stemming from the nucleus can be resolved and tested as, due to the identical electron configuration, many common QED contributions do not have to be considered. Experimentally however, this becomes quickly limited, particularly by the precision of the ion masses or the achievable magnetic field stability [8]. Here we report on a novel measurement technique that overcomes both of these limitations by cotrapping two HCIs in a Penning trap and measuring the difference of their g facto...
Developments for the direct determination of the g-factor of a single proton in a Penning trap
Hyperfine Interactions, 2009
The measurement and comparison of the magnetic moment (or g-factor) of the proton and antiproton provide a stringent experimental test of the CPTtheorem in the baryonic sector (Quint et al., Nucl Instrum Methods Phys Res, B 214:207, 2004). We present an experimental setup for the first direct high-precision measurement of the g-factor of a single isolated proton in a double cylindrical Penning trap. The application of the continuous Stern-Gerlach effect to detect quantum jumps between the two spin states of the particle, together with a novel trap design specially developed for this purpose, offers the possibility of measuring the magnetic moment not only of a single proton but also of a single antiproton. It is aimed to achieve a relative uncertainty of 10 −9 or better. Preliminary results including mass spectra of particle clouds as well as single proton preparation and detection are shown.
Electrong-factor determinations in Penning traps
Annalen der Physik, 2013
The magnetic moment of the electron, expressed by the g-factor in units of the Bohr magneton, is a key quantity in the theory of quantum electrodynamics (QED). Experiments using single particles confined in Penning traps have provided very precise values of the g-factor for the free electron as well as the electron bound in hydrogen-like ions. In this paper the status of these experiments is reviewed. The results allow testing calculations of higher order Feynman diagrams. Comparison of experimental and theoretical results for free and bound particles show no discrepancy within the limits of error, thus representing to date the most sensitive test of QED. Moreover, the g-factor provides a unique access to fundamental constants, as e.g. the electron mass or the fine structure constant.
Measurement of the gJ factor of a bound electron in hydrogen-like oxygen 16O7
Canadian Journal of Physics, 2002
The magnetic moment of the electron bound in hydrogen-like oxygen O · has been determined using the "continuous Stern-Gerlach-effect" in a double Penning trap. We obtained a relative precision of ¾ ¢ ½¼ . This tests calculations of bound state-quantum electrodynamics and nuclear correction.
Electron Magnetic Moment in Highly Charged Ions: The ARTEMIS Experiment
Annalen der Physik, 2018
The magnetic moment (g-factor) of the electron is a fundamental quantity in physics that can be measured with high accuracy by spectroscopy in Penning traps. Its value has been predicted by theory, both for the case of the free (unbound) electron and for the electron bound in a highly charged ion. Precision measurements of the electron magnetic moment yield a stringent test of these predictions and can in turn be used for a determination of fundamental constants such as the fine structure constant or the atomic mass of the electron. For the bound-electron magnetic-moment measurement, two complementary approaches exist, one via the so-called "continuous Stern-Gerlach effect", applied to ions with zero-spin nuclei, and one a spectroscopic approach, applied to ions with nonzero nuclear spin. Here, the latter approach is detailed, and an overview of the experiment and its status is given.
Highly Accurate Measurement of the Electron Orbital Magnetic Moment
arXiv (Cornell University), 2015
We propose to accurately determine the orbital magnetic moment of the electron by measuring, in a Magneto-Optical or Ion trap, the ratio of the Lande g-factors in two atomic states. From the measurement of (g J1 /g J2), the quantity A = (αδ S-βδ L) can be extracted, if the states are LS coupled. The indirectly measured quantity is a linear combination of the δ S and δ L which are, respectively, the corrections to the spin and orbital g-factors where α, β are constants. Given that highly accurate values of δs are currently available, accurate values of δ L may also be determined. At present, the correction δ L = (-1.8 ± 0.4) x 10-4 has been determined by using earlier measurements of the ratio of the g-factors, made on the Indium 2 P 1/2 and 2 P 3/2 states.