156 research outputs found

    Observation of Spin Flips with a Single Trapped Proton

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    Radio-frequency induced spin transitions of one individual proton are observed for the first time. The spin quantum jumps are detected via the continuous Stern-Gerlach effect, which is used in an experiment with a single proton stored in a cryogenic Penning trap. This is an important milestone towards a direct high-precision measurement of the magnetic moment of the proton and a new test of the matter-antimatter symmetry in the baryon sector

    Resolution of Single Spin-Flips of a Single Proton

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    The spin magnetic moment of a single proton in a cryogenic Penning trap was coupled to the particle's axial motion with a superimposed magnetic bottle. Jumps in the oscillation frequency indicate spin-flips and were identified using a Bayesian analysis.Comment: accepted for publication by Phys. Rev. Lett., submitted 6.June.201

    Demonstration of the Double Penning Trap Technique with a Single Proton

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    Spin flips of a single proton were driven in a Penning trap with a homogeneous magnetic field. For the spin-state analysis the proton was transported into a second Penning trap with a superimposed magnetic bottle, and the continuous Stern-Gerlach effect was applied. This first demonstration of the double Penning trap technique with a single proton suggests that the antiproton magnetic moment measurement can potentially be improved by three orders of magnitude or more

    Albuterol metered dose inhaler performance under hyperbaric pressures

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    Comparative Medicine - OneHealth and Comparative Medicine Poster SessionINTRODUCTION: The stimulus for this presentation was an asthma attack suffered on the first dive by a victim of a severe industrial electrical burn. The patient's response to albuterol metered dose inhaler (MDI) treatment given at depth was felt to have been poor. We thus wondered what the output of these devises (chlorofluorocarbon or CFC) was at therapeutic depth versus normobaria. As the current MDIs were being phased out of use we also wondered what the comparable output characteristics of the replacement MDIs (hydrofluoroalkane or HFA) would be. MATERIALS AND METHODS: The dose and aerosol particle size and number delivered by MDIs were measured in a hyperbaric chamber at pressures ranging from one atmosphere absolute (1 ATA, 0 feet of seawater, fsw, 101 kPa) to three ATA (66 fsw, 304 kPa). Mass delivered was measured by a Sartorius B120 analytical balance, and particle size analysis by a TSI 3080L electrostatic classifier with a TSI 3776 ultrafine condensation particle counter. RESULTS: Dose delivery per actuation by CFC and long canister HFA powered MDIs was 13Âą1% and 12Âą1% less, respectively, at 3 ATA compared to 1 ATA. However, dose delivery by short canister HFA MDIs was not significantly changed with pressure. The geometric mean diameters of nano particles from the CFC and short canister HFA MDIs decreased from 50 nm at 0 fsw to 32 nm at 66 fsw whereas the long canister HFA aerosol diameters were not affected. The numbers of nanometer size particles delivered at 66 fsw were only 4-7% of those delivered at 0 fsw for the CFC and long canister HFA MDIs; whereas for the short canister HFAs it was 26%. CONCLUSIONS: The doses of albuterol and the sizes and numbers of aerosol particles emitted from albuterol MDIs actuated in a hyperbaric environment vary by canister type; CFC MDI loss is probably unimportant

    Direct measurement of the proton magnetic moment

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    Calculation of electrostatic fields using quasi-Green's functions: application to the hybrid Penning trap.

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    Penning traps offer unique possibilities for storing, manipulating and investigating charged particles with high sensitivity and accuracy. The widespread applications of Penning traps in physics and chemistry comprise e.g. mass spectrometry, laser spectroscopy, measurements of electronic and nuclear magnetic moments, chemical sample analysis and reaction studies. We have developed a method, based on the Green's function approach, which allows for the analytical calculation of the electrostatic properties of a Penning trap with arbitrary electrodes. The ansatz features an extension of Dirichlet's problem to nontrivial geometries and leads to an analytical solution of the Laplace equation. As an example we discuss the toroidal hybrid Penning trap designed for our planned measurements of the magnetic moment of the (anti)proton. As in the case of cylindrical Penning traps, it is possible to optimize the properties of the electric trapping fields, which is mandatory for high-precision experiments with single charged particles. Of particular interest are the anharmonicity compensation, orthogonality and optimum adjustment of frequency shifts by the continuous SternGerlach effect in a quantum jump spectrometer. The mathematical formalism developed goes beyond the mere design of novel Penning traps and has potential applications in other fields of physics and engineering

    Direct high-precision measurement of the magnetic moment of the proton

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    The spin-magnetic moment of the proton μp\mu_p is a fundamental property of this particle. So far μp\mu_p has only been measured indirectly, analysing the spectrum of an atomic hydrogen maser in a magnetic field. Here, we report the direct high-precision measurement of the magnetic moment of a single proton using the double Penning-trap technique. We drive proton-spin quantum jumps by a magnetic radio-frequency field in a Penning trap with a homogeneous magnetic field. The induced spin-transitions are detected in a second trap with a strong superimposed magnetic inhomogeneity. This enables the measurement of the spin-flip probability as a function of the drive frequency. In each measurement the proton's cyclotron frequency is used to determine the magnetic field of the trap. From the normalized resonance curve, we extract the particle's magnetic moment in units of the nuclear magneton μp=2.792847350(9)μN\mu_p=2.792847350(9)\mu_N. This measurement outperforms previous Penning trap measurements in terms of precision by a factor of about 760. It improves the precision of the forty year old indirect measurement, in which significant theoretical bound state corrections were required to obtain μp\mu_p, by a factor of 3. By application of this method to the antiproton magnetic moment μpˉ\mu_{\bar{p}} the fractional precision of the recently reported value can be improved by a factor of at least 1000. Combined with the present result, this will provide a stringent test of matter/antimatter symmetry with baryons.Comment: published in Natur

    The magnetic moments of the proton and the antiproton

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    Recent exciting progress in the preparation and manipulation of the motional quantum states of a single trapped proton enabled the first direct detection of the particle's spin state. Based on this success the proton magnetic moment μp\mu_p was measured with ppm precision in a Penning trap with a superimposed magnetic field inhomogeneity. An improvement by an additional factor of 1000 in precision is possible by application of the so-called double Penning trap technique. In a recent paper we reported the first demonstration of this method with a single trapped proton, which is a major step towards the first direct high-precision measurement of μp\mu_p. The techniques required for the proton can be directly applied to measure the antiproton magnetic moment μpˉ\mu_{\bar{p}}. An improvement in precision of μpˉ\mu_{\bar{p}} by more than three orders of magnitude becomes possible, which will provide one of the most sensitive tests of CPT invariance. To achieve this research goal we are currently setting up the Baryon Antibaryon Symmetry Experiment (BASE) at the antiproton decelerator (AD) of CERN

    The Influence of Education and Socialization on Radicalization: An Exploration of Theoretical Presumptions and Empirical Research

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    Background and Objective: Research into radicalization does not pay much attention to education. This is remarkable and possibly misses an important influence on the process of radicalization. Therefore this article sets out to explore the relation between education on the one hand and the onset or prevention of radicalization on the other hand. Method: This article is a theoretical literature review. It has analyzed empirical studies-mainly from European countries-about the educational aims, content and style of Muslim parents and parents with (extreme) right-wing sympathies. Results: Research examining similarity in right-wing sympathies between parents and children yields mixed results, but studies among adolescents point to a significant concordance. Research also showed that authoritarian parenting may play a significant role. Similar research among Muslim families was not found. While raising children with distrust and an authoritarian style are prevalent, the impact on adolescents has not been investigated. The empirical literature we reviewed does not give sufficient evidence to conclude that democratic ideal in and an authoritative style of education are conducive to the development of a democratic attitude. Conclusion: There is a knowledge gap with regard to the influence of education on the onset or the prevention of radicalization. Schools and families are underappreciated sources of informal social control and social capital and therefore the gap should be closed. If there is a better understanding of the effect of education, policy as well as interventions can be developed to assist parents and teachers in preventing radicalization. Š 2011 The Author(s)

    Keyword: current developments in youth research

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