The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
L.a. Orozco - One of the best experts on this subject based on the ideXlab platform.
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isotope shifts in the 7s rightarrow 8s transition of Francium measurements and comparison to textit ab initio theory
arXiv: Atomic Physics, 2017Co-Authors: M R Kalita, L.a. Orozco, S Aubin, J A Behr, A Gorelov, G Gwinner, M R Pearson, A C Dehart, M J Kossin, E. GomezAbstract:We observe the electric-dipole forbidden $7s\rightarrow8s$ transition in the Francium isotopes $^{208-211}$Fr and $^{213}$Fr using a two-photon excitation scheme. We collect the atoms online from an accelerator and confine them in a magneto optical trap for the measurements. In combination with previous measurements of the $7s\rightarrow7p_{1/2}$ transition we perform a King Plot analysis. We compare the thus determined ratio of the field shift constants (1.230 $\pm$ 0.019) to results obtained from new ab initio calculations (1.234 $\pm$ 0.010) and find excellent agreement.
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photoionization of the Francium 7p3 2 state
Canadian Journal of Physics, 2017Co-Authors: R Collister, E. Gomez, L.a. Orozco, M Tandecki, S Aubin, G Gwinner, Jiehang Zhang, Matthew Pearson, J A BehrAbstract:We have measured the non-resonant photoionization cross section of the 7P3/2 state of Francium for 442 nm light to be 20.8 ± 7.1 Mb. Atoms were irradiated in a magneto-optical trap, and we deduce the photoionization rate from the change in trap lifetime. The result is consistent with a simple extrapolation of known cross sections for other alkali atoms.
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efficient inter trap transfer of cold Francium atoms
Hyperfine Interactions, 2016Co-Authors: J Zhang, E. Gomez, R Collister, K Shiells, M Tandecki, S Aubin, J A Behr, A Gorelov, G Gwinner, L.a. OrozcoAbstract:We report on the status of the FrPNC experiments and summarize our plans for measurements of parity non-conservation (PNC) in a sample of cold Francium. The FrPNC collaboration has commissioned a laser cooling apparatus at the TRIUMF accelerator that collects and cools Francium atoms for PNC experiments. We have recently demonstrated the robust, high efficiency transfer (50 %) of laser cooled Francium atoms to a second laser cooling apparatus, located 0.7 m below the first, where the PNC experiments will be conducted.
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isotope shifts in Francium isotopes fr 206 213 and fr 221
Physical Review A, 2014Co-Authors: R Collister, L.a. Orozco, J Zhang, M Tandecki, S Aubin, J A Behr, G Gwinner, M R Pearson, E. GomezAbstract:We present the isotope shifts of the 7s1/2 to 7p1/2 transition for Francium isotopes ²⁰⁶⁻²¹³Fr with reference to ²²¹Fr collected from two experimental periods. The shifts are measured on a sample of atoms prepared within a magneto-optical trap by a fast sweep of radio-frequency sidebands applied to a carrier laser. King plot analysis, which includes literature values for 7s1/2 to 7p3/2 isotope shifts, provides a field shift constant ratio of 1.0520(10) and a difference between the specific mass shift constants of 170(100) GHz amu between the D₁ and D₂ transitions, of sufficient precision to differentiate between ab initio calculations.
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commissioning of the Francium trapping facility at triumf
Journal of Instrumentation, 2013Co-Authors: M Tandecki, E. Gomez, L.a. Orozco, R Collister, S Aubin, J A Behr, G Gwinner, Jiehang Zhang, M R PearsonAbstract:We report on the successful commissioning of the Francium Trapping Facility at TRIUMF. Large laser-cooled samples of Francium are produced from a Francium ion beam delivered by the ISAC radioactive ion beam facility. The ion beam is neutralized on an yttrium foil, which is subsequently heated to transfer the atoms into the magneto-optical trapping region. We have successfully trapped 207Fr, 209Fr and 221Fr, with a maximum of 2.5 × 105 209Fr atoms. The neutral cold atoms will be used in studies of the weak interaction through measurements of atomic parity non-conservation.
E. Gomez - One of the best experts on this subject based on the ideXlab platform.
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isotope shifts in the 7s rightarrow 8s transition of Francium measurements and comparison to textit ab initio theory
arXiv: Atomic Physics, 2017Co-Authors: M R Kalita, L.a. Orozco, S Aubin, J A Behr, A Gorelov, G Gwinner, M R Pearson, A C Dehart, M J Kossin, E. GomezAbstract:We observe the electric-dipole forbidden $7s\rightarrow8s$ transition in the Francium isotopes $^{208-211}$Fr and $^{213}$Fr using a two-photon excitation scheme. We collect the atoms online from an accelerator and confine them in a magneto optical trap for the measurements. In combination with previous measurements of the $7s\rightarrow7p_{1/2}$ transition we perform a King Plot analysis. We compare the thus determined ratio of the field shift constants (1.230 $\pm$ 0.019) to results obtained from new ab initio calculations (1.234 $\pm$ 0.010) and find excellent agreement.
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photoionization of the Francium 7p3 2 state
Canadian Journal of Physics, 2017Co-Authors: R Collister, E. Gomez, L.a. Orozco, M Tandecki, S Aubin, G Gwinner, Jiehang Zhang, Matthew Pearson, J A BehrAbstract:We have measured the non-resonant photoionization cross section of the 7P3/2 state of Francium for 442 nm light to be 20.8 ± 7.1 Mb. Atoms were irradiated in a magneto-optical trap, and we deduce the photoionization rate from the change in trap lifetime. The result is consistent with a simple extrapolation of known cross sections for other alkali atoms.
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efficient inter trap transfer of cold Francium atoms
Hyperfine Interactions, 2016Co-Authors: J Zhang, E. Gomez, R Collister, K Shiells, M Tandecki, S Aubin, J A Behr, A Gorelov, G Gwinner, L.a. OrozcoAbstract:We report on the status of the FrPNC experiments and summarize our plans for measurements of parity non-conservation (PNC) in a sample of cold Francium. The FrPNC collaboration has commissioned a laser cooling apparatus at the TRIUMF accelerator that collects and cools Francium atoms for PNC experiments. We have recently demonstrated the robust, high efficiency transfer (50 %) of laser cooled Francium atoms to a second laser cooling apparatus, located 0.7 m below the first, where the PNC experiments will be conducted.
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isotope shifts in Francium isotopes fr 206 213 and fr 221
Physical Review A, 2014Co-Authors: R Collister, L.a. Orozco, J Zhang, M Tandecki, S Aubin, J A Behr, G Gwinner, M R Pearson, E. GomezAbstract:We present the isotope shifts of the 7s1/2 to 7p1/2 transition for Francium isotopes ²⁰⁶⁻²¹³Fr with reference to ²²¹Fr collected from two experimental periods. The shifts are measured on a sample of atoms prepared within a magneto-optical trap by a fast sweep of radio-frequency sidebands applied to a carrier laser. King plot analysis, which includes literature values for 7s1/2 to 7p3/2 isotope shifts, provides a field shift constant ratio of 1.0520(10) and a difference between the specific mass shift constants of 170(100) GHz amu between the D₁ and D₂ transitions, of sufficient precision to differentiate between ab initio calculations.
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commissioning of the Francium trapping facility at triumf
Journal of Instrumentation, 2013Co-Authors: M Tandecki, E. Gomez, L.a. Orozco, R Collister, S Aubin, J A Behr, G Gwinner, Jiehang Zhang, M R PearsonAbstract:We report on the successful commissioning of the Francium Trapping Facility at TRIUMF. Large laser-cooled samples of Francium are produced from a Francium ion beam delivered by the ISAC radioactive ion beam facility. The ion beam is neutralized on an yttrium foil, which is subsequently heated to transfer the atoms into the magneto-optical trapping region. We have successfully trapped 207Fr, 209Fr and 221Fr, with a maximum of 2.5 × 105 209Fr atoms. The neutral cold atoms will be used in studies of the weak interaction through measurements of atomic parity non-conservation.
G.d. Sprouse - One of the best experts on this subject based on the ideXlab platform.
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Spectroscopy of Francium Isotopes
Physica Scripta, 2020Co-Authors: J. S. Grossman, M R Pearson, Luis A Orozco, G.d. SprouseAbstract:We have performed precision spectroscopy on cold Francium atoms in a magneto optical trap. Our measurements test the present ab initio calculations for the understanding of the electronic structure of the atom. We probe the distribution of the nuclear magnetization through measurements of the 7P1/2 hyperfine splitting in a chain of neutron deficient Francium isotopes.
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the frpnc experiment at triumf atomic parity non conservation in Francium
19TH PARTICLES AND NUCLEI INTERNATIONAL CONFERENCE (PANIC11), 2012Co-Authors: S Aubin, E. Gomez, R Collister, J A Behr, Jiehang Zhang, M R Pearson, Dong Sheng, V V Flambaum, D Melconian, G.d. SprouseAbstract:The FrPNC collaboration has begun the construction of an on-line laser cooling and trapping apparatus at TRIUMF to measure atomic parity non-conservation (PNC) and the nuclear anapole moment in a string of artificially produced Francium isotopes. Atomic PNC experiments provide unique high precision tests of the electroweak sector of the Standard Model at very low energies. Furthermore, precision measurements of spin-dependent atomic PNC can determine nuclear anapole moments and probe the weak force within the nucleus. Francium is an excellent candidate for precision measurements of atomic PNC due to its simple electronic structure and enhanced parity violation: both the optical PNC and anapole moment signals are expected to be over an order of magnitude larger than in cesium.
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program of parity nonconservation measurements in Francium
2007Co-Authors: G Gwinner, E. Gomez, G.d. Sprouse, L.a. Orozco, J A Behr, Dong Sheng, K P Jackson, Perez A Galvan, Y Zhao, M R PearsonAbstract:A program to study parity nonconservation in Francium at TRIUMF is presented. The essential part of the experiment will be a collection of ≈ 106 trapped atoms on-line at the ISAC radioactive beam facility. The atoms can be excited through a parity-forbidden E1 transition either in the microwave or in the optical regime. The rate of excitation gives information on the weak nucleon-nucleon interactions through the anapole moment of the Fr nucleus.
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spectroscopy with trapped Francium advances and perspectives for weak interaction studies
Reports on Progress in Physics, 2006Co-Authors: E. Gomez, L.a. Orozco, G.d. SprouseAbstract:Francium is a candidate for atomic parity non-conservation (PNC) experiments. Its simple atomic structure has been the subject of extensive experimental research facilitated by the ability to trap and cool significant numbers of atoms. The studies include the location of energy levels, their hyperfine splittings and their lifetime. All of these levels are close to the ground state. The results show a remarkable agreement with calculated ab initio properties to a degree that is comparable with other stable alkali atoms. The quantitative understanding of Francium has made possible the exploration of avenues for a PNC measurement in the optical and the microwave regimes. These precision experiments have the potential to enhance our understanding of the weak coupling constants between electrons and nucleons, as well as between nucleons.
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Spectroscopy of Francium: lifetime measurement of the 8s level and investigations of cold collisions
2005 Quantum Electronics and Laser Science Conference, 2005Co-Authors: E. Gomez, G.d. Sprouse, H. Hwang, A. Perez-galvan, L.a. OrozcoAbstract:We present spectroscopic investigations of Francium that include the measurement of the lifetime of the 8s level and photoassociation spectroscopy to look at the formation of Francium molecules.
M R Pearson - One of the best experts on this subject based on the ideXlab platform.
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Spectroscopy of Francium Isotopes
Physica Scripta, 2020Co-Authors: J. S. Grossman, M R Pearson, Luis A Orozco, G.d. SprouseAbstract:We have performed precision spectroscopy on cold Francium atoms in a magneto optical trap. Our measurements test the present ab initio calculations for the understanding of the electronic structure of the atom. We probe the distribution of the nuclear magnetization through measurements of the 7P1/2 hyperfine splitting in a chain of neutron deficient Francium isotopes.
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isotope shifts in the 7s rightarrow 8s transition of Francium measurements and comparison to textit ab initio theory
arXiv: Atomic Physics, 2017Co-Authors: M R Kalita, L.a. Orozco, S Aubin, J A Behr, A Gorelov, G Gwinner, M R Pearson, A C Dehart, M J Kossin, E. GomezAbstract:We observe the electric-dipole forbidden $7s\rightarrow8s$ transition in the Francium isotopes $^{208-211}$Fr and $^{213}$Fr using a two-photon excitation scheme. We collect the atoms online from an accelerator and confine them in a magneto optical trap for the measurements. In combination with previous measurements of the $7s\rightarrow7p_{1/2}$ transition we perform a King Plot analysis. We compare the thus determined ratio of the field shift constants (1.230 $\pm$ 0.019) to results obtained from new ab initio calculations (1.234 $\pm$ 0.010) and find excellent agreement.
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Isotope Shifts in the 7s$\rightarrow$8s Transition of Francium: Measurements and Comparison to \textit{ab initio} Theory
arXiv: Atomic Physics, 2017Co-Authors: M R Kalita, Luis A Orozco, A Gorelov, M R Pearson, Gerald Gwinner, Seth Aubin, John Behr, A C Dehart, M J Kossin, Eduardo GomezAbstract:We observe the electric-dipole forbidden $7s\rightarrow8s$ transition in the Francium isotopes $^{208-211}$Fr and $^{213}$Fr using a two-photon excitation scheme. We collect the atoms online from an accelerator and confine them in a magneto optical trap for the measurements. In combination with previous measurements of the $7s\rightarrow7p_{1/2}$ transition we perform a King Plot analysis. We compare the thus determined ratio of the field shift constants (1.230 $\pm$ 0.019) to results obtained from new ab initio calculations (1.234 $\pm$ 0.010) and find excellent agreement.
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Isotope shifts in Francium isotopes Fr -213 206 and 221 Fr
Physical Review A, 2014Co-Authors: R Collister, Luis A Orozco, J Zhang, M Tandecki, M R Pearson, Gerald Gwinner, Seth Aubin, John Behr, Eduardo GomezAbstract:We present the isotope shifts of the 7s1/2 to 7p1/2 transition for Francium isotopes ²⁰⁶⁻²¹³Fr with reference to ²²¹Fr collected from two experimental periods. The shifts are measured on a sample of atoms prepared within a magneto-optical trap by a fast sweep of radio-frequency sidebands applied to a carrier laser. King plot analysis, which includes literature values for 7s1/2 to 7p3/2 isotope shifts, provides a field shift constant ratio of 1.0520(10) and a difference between the specific mass shift constants of 170(100) GHz amu between the D₁ and D₂ transitions, of sufficient precision to differentiate between ab initio calculations.
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isotope shifts in Francium isotopes fr 206 213 and fr 221
Physical Review A, 2014Co-Authors: R Collister, L.a. Orozco, J Zhang, M Tandecki, S Aubin, J A Behr, G Gwinner, M R Pearson, E. GomezAbstract:We present the isotope shifts of the 7s1/2 to 7p1/2 transition for Francium isotopes ²⁰⁶⁻²¹³Fr with reference to ²²¹Fr collected from two experimental periods. The shifts are measured on a sample of atoms prepared within a magneto-optical trap by a fast sweep of radio-frequency sidebands applied to a carrier laser. King plot analysis, which includes literature values for 7s1/2 to 7p3/2 isotope shifts, provides a field shift constant ratio of 1.0520(10) and a difference between the specific mass shift constants of 170(100) GHz amu between the D₁ and D₂ transitions, of sufficient precision to differentiate between ab initio calculations.
A Dainelli - One of the best experts on this subject based on the ideXlab platform.
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Observation of 7p²P₃/₂ -> 7d²D optical transitions in 209 and 210 Francium isotopes
Optics Letters, 2017Co-Authors: S Agustsson, L Corradi, A Dainelli, A Khanbekyan, E Mariotti, Carmela Marinelli, Luca Marmugi, Giovanni Bianchi, Roberto Calabrese, G MazzoccaAbstract:We report on the direct experimental observation of the 7pP23/2→7dD2 optical transitions in 209 and 210 Francium isotopes. By continuously monitoring the fluorescence emitted by the isotopes collected in a magneto-optical trap (MOT), the electric dipole transitions 7pP23/2→7dD25/2 of Fr209, not yet experimentally observed, and 7pP23/2→7dD25/2, 7pP23/2→7dD25/2 of Fr210 were detected as sub-Doppler depletion dips of the cold atom population. This approach allowed unambiguous identification of the excited state hyperfine structures, even in the absence of a large stable vapor. Our findings demonstrate the effectiveness and the flexibility of fluorescence monitoring of trap depletion upon laser excitation, and broaden the experimental knowledge of Francium isotopes and their electronic and nuclear properties. These results will have a relevant impact on ongoing researches for low-energy testing of fundamental symmetries with Francium, from atomic parity non-conservation to the electron dipole moment.
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observation of 7p p 7d d optical transitions in 209 and 210 Francium isotopes
Optics Letters, 2017Co-Authors: S Agustsson, R Calabrese, L Corradi, A Dainelli, A Khanbekyan, E Mariotti, Carmela Marinelli, Luca Marmugi, Giovanni Bianchi, G MazzoccaAbstract:We report on the direct experimental observation of the 7pP23/2→7dD2 optical transitions in 209 and 210 Francium isotopes. By continuously monitoring the fluorescence emitted by the isotopes collected in a magneto-optical trap (MOT), the electric dipole transitions 7pP23/2→7dD25/2 of Fr209, not yet experimentally observed, and 7pP23/2→7dD25/2, 7pP23/2→7dD25/2 of Fr210 were detected as sub-Doppler depletion dips of the cold atom population. This approach allowed unambiguous identification of the excited state hyperfine structures, even in the absence of a large stable vapor. Our findings demonstrate the effectiveness and the flexibility of fluorescence monitoring of trap depletion upon laser excitation, and broaden the experimental knowledge of Francium isotopes and their electronic and nuclear properties. These results will have a relevant impact on ongoing researches for low-energy testing of fundamental symmetries with Francium, from atomic parity non-conservation to the electron dipole moment.
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Francium trapping at the infn lnl facility
International Journal of Modern Physics E-nuclear Physics, 2014Co-Authors: E Mariotti, R Calabrese, L Corradi, A Dainelli, A Khanbekyan, Carmela Marinelli, Luca Marmugi, G Mazzocca, L TomassettiAbstract:A brief review of the Francium trapping experiments at the INFN-LNL facility is presented in the wide context of Atomic Parity-Nonconservation (APNC), which, as long as acquiring more precise and new spectroscopic data on the Francium isotopes, is the ultimate goal of the experiment. Due to its instability, Francium atoms must be produced continuously by a nuclear fusion–evaporation reaction into a heated Gold target hit by a beam of accelerated oxygen ions. Francium is then extracted in the ionic form and guided by an electrostatic line to the actual science chamber, where the ions are neutralized. Atoms are then cooled down and trapped in a Magneto-Optical Trap (MOT) to ensure both the availability of a sufficiently populated and stable atomic sample and to eliminate the Doppler broadening which would affect the precision of the measurements. A review of the recent improvements to the experimental apparatus and to the detection techniques that led to a sensitivity better than five atoms is presented. The final part of this paper deals with a summary of the recent results obtained by our collaboration and a short outlook for the immediate future.
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accurate measurements of transition frequencies and isotope shifts of laser trapped Francium
Optics Letters, 2009Co-Authors: S Sanguinetti, R Calabrese, L Corradi, A Dainelli, C De Mauro, A Khanbekyan, E Mariotti, P Minguzzi, G Stancari, L TomassettiAbstract:An interferometric method is used to improve the accuracy of the 7S−7P transition frequencies of three Francium isotopes by 1 order of magnitude. The deduced isotope shifts for 209–211Fr confirm the ISOLDE data. The frequency of the D2 transition of 212Fr--the accepted reference for all Fr isotope shifts--is revised, and a significant difference with the ISOLDE value is found. Our results will be a benchmark for the accuracy of the theory of Fr energy levels, a necessary step to investigate fundamental symmetries.
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a Francium mot for atomic parity violation measurements
15th International School on Quantum Electronics: Laser Physics and Applications, 2008Co-Authors: S N Atutov, R Calabrese, L Corradi, A Dainelli, C De Mauro, A Khanbekyan, E Mariotti, P Minguzzi, S Sanguinetti, G StancariAbstract:The apparatus for the production and trapping of Francium is described and its performances are reported. Latest results on magneto-optical trapping of Francium are summarized: trapping of 209, 210, 211 Francium isotopes, measurements of their trapping frequencies, measurements of diffusion parameters of Francium ions in yttrium. Future experiments on fundamental physics are presented.
