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In Japan, research activities by junior and senior high school students show an upward trend. However, there are limited examples of research activities in the field of elementary particles and atoms. This is due to the difficulty associated with procuring research tools such as accelerators or particle detectors. Therefore, we hosted the ‘Accel Kitchen’ in 2018 and 2019 at the Cyclotron and Radioisotope Center (CYRIC) in Tohoku University where junior and senior high school students could participate in ongoing research of particle and atomic physics. At each workshop, 12 junior and senior high school students participated in the beam experiment, including the production of francium atoms (Fr) by the fusion reaction of oxygen and gold, optimizing the transport of the ion beam and identifying the alpha decay nuclei, and laser trapping of Fr for two days. Each group that was involved in the experiment was supported by researchers and university students who acted as mentors. This was the first opportunity for junior and senior high school students to know about the particle beam experiment in Japan. [ABSTRACT FROM AUTHOR]

At CERN-ISOLDE, high-purity radioactive ion beams of 219Fr and 221RaF were investigated with α -decay spectroscopy at the CRIS and ASET experiments in the course of three different experimental campaigns. The half-life of 215At, α -decay daughter of 219Fr, is measured to be 36.3(3)[9] μ s , and that of 221Ra was determined to be 26.2(1)[6] s, both of which are well in line with the trends in this region of the nuclear landscape but at odds with some of the reported literature. [ABSTRACT FROM AUTHOR]

Molecules with unstable isotopes often contain heavy and deformed nuclei and thus possess a high sensitivity to parity-violating effects, such as the Schiff moments. Currently the best limits on Schiff moments are set with diamagnetic atoms. Polar molecules with quantum-enhanced sensing capabilities, however, can offer better sensitivity. In this work, we consider the prototypical ^223 Fr ^107 Ag molecule, as the octupole deformation of the unstable ^223 Fr francium nucleus amplifies the nuclear Schiff moment of the molecule by two orders of magnitude relative to that of spherical nuclei and as the silver atom has a large electron affinity. To develop a competitive experimental platform based on molecular quantum systems, ^223 Fr atoms and ^107 Ag atoms have to be brought together at ultracold temperatures. That is, we explore the prospects of forming ^223 Fr ^107 Ag from laser-cooled Fr and Ag atoms. We have performed fully relativistic electronic-structure calculations of ground and excited states of FrAg that account for the strong spin-dependent relativistic effects of Fr and the strong ionic bond to Ag. In addition, we predict the nearest-neighbor densities of magnetic-field Feshbach resonances in ultracold ^223 Fr + ^107 Ag collisions with coupled-channel calculations. These resonances can be used for magneto-association into ultracold, weakly-bound FrAg. We also determine the conditions for creating ^223 Fr ^107 Ag molecules in their absolute ground state from these weakly-bound dimers via stimulated Raman adiabatic passage using our calculations of the relativistic transition electric dipole moments.

A comparison of the ion exchange properties of the inorganic resin Isolute SCX-2 with alkali metal cations, including francium, to the organic Dowex 50X8 resin is presented. The purpose of this study was to investigate the ion exchange properties of the alkali metal cations with a resin containing a less hydrophobic backbone structure. It was found that the less hydrophobic Isolute SCX-2 resin had a smaller range of values for the distribution coefficients when exchanged with the alkali metals than Dowex 50X8. [ABSTRACT FROM AUTHOR]

A computer simulation of the radioactive isotope beam targets used at the Isotope Separation and ACceleration (ISAC) facility of TRIUMF was built, to support target material development. The simulation was constructed using the GEANT4 nuclear transport toolkit, and can simulate the production rate of isotopes from user-defined beam and target characteristics. This GEANT4 simulation produces isotopes using the Liège intra-nuclear cascade, coupled to the ABLAv3 de-excitation code and consists of a primary 480 MeV proton beam impinging upon a production target. The isotopes produced by this interaction are used to calculate in-target production rates. Results from the simulation are presented, alongside an analysis of the release times of a subset of the francium isotopes, 211–214 Fr. [ABSTRACT FROM AUTHOR]

Various isotopes of Ac, Ra, Fr, and Rn were produced by fusion-evaporation reactions using a 48 Ca beam. The energetic ions were stopped in and extracted from a helium gas cell. The extracted ions were identified using a multi-reflection time-of-fight mass spectrograph. In all cases, it was observed that the predominant charge state for the extracted ions, including the alkali Fr, was 2+. [ABSTRACT FROM AUTHOR]

Segmented all-electron basis sets of valence double and triple zeta qualities plus polarization functions for the elements Fr, Ra, and Ac are generated using non-relativistic and Douglas-Kroll-Hess (DKH) Hamiltonians. The sets are augmented with diffuse functions with the purpose to describe appropriately the electrons far from the nuclei. At the DKH-B3LYP level, first atomic ionization energies and bond lengths, dissociation energies, and polarizabilities of a sample of diatomics are calculated. Comparison with theoretical and experimental data available in the literature is carried out. It is verified that despite the small sizes of the basis sets, they are yet reliable. [ABSTRACT FROM AUTHOR]

Mass-separated francium beams ( 211 Fr or 213 Fr) were implanted into solid targets for producing 211 Rn (14.6 h half-life) or 209 At (5.41 h), in situ . 211 Rn was transferred to dodecane and isolated from contaminants, providing sources for 211 At (7.21 h) production by 211 Rn decay (73%). 209 At was recovered with high radionuclidic purity in aqueous solutions, directly. These experiments demonstrated Fr beam implantations as a novel method for producing preclinical quantities of 211 Rn/ 211 At (for therapy) and 209 At (for imaging). [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Here we synthesize a two-step Fr 13 risk assessment ( Davey et al., 2015 ; Davey, 2015 ) for the first time. We demonstrate it with vulnerability to fouling in an apparent steady-state global process of integrated cross-flow ultrafiltration and osmotic distillation (UF-OD) for concentration of fruit juice. Integrated two-step membrane processing of juices is becoming widespread as an alternative to thermal treatment. The aim was to advance the Fr 13 framework to investigate how naturally occurring, random fluctuations in apparent steady-state plant parameters can be transmitted and impact in progressively multi-step complex (i.e. integrated not ‘complicated’) processes. Membrane behavior is simulated using Monte Carlo (with Latin Hypercube) sampling of transmembrane pressure (∆ P UF 1-1 ) and filtration time ( t UF 1-1 ) with independent data for concentrating pomegranate juice ( Punica granatum ). Membranes fouling is defined as a permeate flux less than the operational design flux. Overall global failure of the integrated two-step UF-OD is defined as an unwanted OD flux ( J OD 1-2 < J OD 1-2 , required plus 3% tolerance). Results show the Fr 13 method is applicable to an integrated two-step process. The integrated UF-OD is expected to be vulnerable to surprise fouling in 10.5% of all operations, over an extended time. Findings are used to assess re-design for reduced membrane vulnerability to fouling in second-tier studies. Results appear generalizable and could be applied to a range of integrated two-step processing. Outcomes will be of interest to risk analysts and manufacturers of membrane equipment. This work is part of an overall development and investigation of Fr 13 as a new quantitative risk assessment and equipment design tool. [ABSTRACT FROM AUTHOR]

High-resolution laser spectroscopy was performed on 206Fr with the collinear resonance ionization spectroscopy (CRIS) experiment at CERN-ISOLDE. The hyperfine structure and isotope shift of the ground, first isomeric and second isomeric states were measured. The hyperfine components were unambiguously assigned to each nuclear state by means of laser-assisted nuclear decay spectroscopy. The branching ratios in the a decay of 206Fr and 202At were also measured for the first time with isomerically purified beams. The extracted hindrance factors allow determination of the spin of the ground, first isomeric, and second isomeric states in 202At and 198Bi. [ABSTRACT FROM AUTHOR]

We are planning test experiments of fundamental symmetries based on the intrinsic properties of francium. It is expected that the laser cooling and trapping of francium will produce precision measurements. The pilot experiment using rubidium was performed with the goal of francium trapping. The ion beam generated with a francium ion source was investigated using a Wien filter. Each piece of equipment still must be studied in more detail, and the equipment should be upgraded in order to trap radioactive atoms. [ABSTRACT FROM AUTHOR]

We have measured the hyperfine splitting of the 7P1/2 state at the 100 ppm level in Fr isotopes (206g,206m,207,209,213,221Fr) near the closed neutron shell (N=126 in Fr213). The measurements in five isotopes and a nuclear isomeric state of francium, combined with previous determinations of the 7S1/2 splittings, reveal the spatial distribution of the nuclear magnetization, i.e., the Bohr-Weisskopf effect. We compare our results with a simple shell model consisting of unpaired single valence nucleons orbiting a spherical nucleus, and find good agreement over a range of neutron-deficient isotopes (Fr207-213). Also, we find near-constant proton anomalies for several even-N isotopes. This identifies a set of Fr isotopes whose nuclear structure can be understood well enough for the extraction of weak interaction parameters from parity nonconservation studies. [ABSTRACT FROM AUTHOR]

A laser cooled heavy atom is one of the candidates to search for the permanent electric dipole moment (EDM) of the electron due to the enhancement mechanism and its long coherence time. The laser cooled francium (Fr) factory has been constructed to perform the electron EDM search at the Cyclotron and Radioisotope Center, Tohoku University. The present status of Fr production and the EDM measurement system is presented. [ABSTRACT FROM AUTHOR]

Collinear laser fluorescence spectroscopy has been performed on the ground and isomeric states 0f 204,206Fr in order to determine their spins, nuclear moments, and changes in mean-squared charge radii. A new experimental technique has been developed as part of this work which much enhances the data collection rate while maintaining the high resolution. This has permitted the extension of this study to the two isomeric states in each nucleus. The investigation of nuclear g factors and mean-squared charge radii indicates that the neutron-deficient Fr isotopes lie in a transitional region from spherical towards more collective structures. [ABSTRACT FROM AUTHOR]

We study the bulk properties such as binding energy (BE), root-mean-square (RMS) charge radius, quadrupole deformation etc. for Francium (Fr) isotopes having mass number A = 180-240 within the framework of relativistic mean field (RMF) theory. Systematic comparisons are made between the calculated results from RMF theory, Finite Range Droplet Model (FRDM) and the experimental data. Most of the nuclei in the isotopic chain shows prolate configuration in their ground state. The α-decay properties like α-decay energy and the decay half-life are also estimated for three different chains of 198Fr, 199Fr and 200Fr. The calculation for the decay half-life are carried out by taking two different empirical formulae and the results are compared with the experimental data. [ABSTRACT FROM AUTHOR]

In order to improve the structural stability and discharge capacity of Li[Ni 0.6 Co 0.1 Mn 0.3 ]O 2 (core), we designed the core shell structure of Li[(Ni 0.6 Co 0.1 Mn 0.3 ) 0.36 (Ni 0.8 Co 0.15 Al 0.05 ) 0.64 ]O 2 (core shell). The result of an EDS line analysis showed that the core of the low cost NCM and the shell of high nickel NCA were successfully synthesized as two phases. In this structural analysis, the core shell cathode material showed a reduction of cation mixing as compared with the core. In addition, the structural stability was enhanced by a hexagonal ordering. Because the structural stability is improved, the electrochemical properties showed that the core shell electrode remarkably improved its cycleability and discharge capacity as compared with the core. To the best of our knowledge, this result is the first report of the synthesis of a new composition. Also, it is effective because of the relatively low cost of using the NCM core of low cobalt. [ABSTRACT FROM AUTHOR]

Fe(PO)(OH) loaded with Au (mass ratio = 0, 0.5, 2, 4, 6 %) was synthesized via two steps, combining microemulsion and hydrothermal techniques, and the effects of the Au loading on the electrochemical properties of Fe(PO)(OH) cathode material were investigated. The structure and morphology were studied by means of X-ray diffraction (XRD) and field emission-scanning electron microscopy (FE-SEM), and the electrochemical performances were characterized by galvanostatic charge and discharge tests. The XRD patterns showed that the Au loading modification did not affect the structure of Fe(PO)(OH). From the charge and discharge test, it was found that when the mass ratio of Au loading was 2 % the sample exhibited excellent electrochemical properties with an initial specific capacity of 182 mAhg at 0.1 C and less fading of the specific capacity, retaining about 165 mAhg after 25 cycles, which demonstrated that the Au loading is an effective way to improve the electron conductivity of Fe(PO)(OH). What is more, the electrochemical properties of Fe(PO)(OH)/Au synthesized at 150 °C for 24 h with a discharge specific capacity of 182 mAhg are better than those of the sample synthesized at 180 °C for 24 h with a discharge specific capacity of 121 mAhg, which is attributed to the crystal growth of particles at high hydrothermal temperatures, showing that the particle size also has a significant influence on the electrochemical performance of electrode materials. [ABSTRACT FROM AUTHOR]

The masses of 222,224,226-233Fr and 233,234Ra have been determined with the Penning-trap mass spectrometer ISOLTRAP at the ISOLDE facility at CERN, including the previously unknown mass and half-life of 233Fr. We study the evolution of the odd-even staggering of binding energies along the francium and radium isotopic chains and of its lowest-order estimator, △³(N). An enhancement of the staggering of △³(N) is observed towards neutron number N = 146, which points to contributions beyond pairing correlations. These contributions are investigated in the Hartree-Fock and Hartree-Fock-Bogoliubov approaches, emphasizing the connections to the single-particle level density and nuclear deformation. [ABSTRACT FROM AUTHOR]

Decay properties of the neutron-deficient nuclides 201-203Ra and 200-202Fr were investigated using α- and γ-decay spectroscopy. The nuclei were produced in fusion-evaporation reactions of 56Fe projectiles with enriched 147Sm and 149Sm targets at the velocity filter SHIP at GSI in Darmstadt (Germany). The α decay from the (3/2-) state in 201Ra was identified with an energy Eα = 7842(12) keV and half-life T1/2 = 8-4+40 ms. Ambiguous decay properties for 202Ra from previous measurements were clarified by remeasuring with significantly improved precision, resulting in values of Eα = 7722(7) keV and T1/2 = 3.8-0.8+1.3 ms. New short-lived isomeric states were identified in 200Fr and 201Fr with half-lives of 0.6-0.2+0.5 μs and 0.7-0.2+0.5 μs, respectively. A tentative spin and parity of 13/2+ were assigned to the latter. One event attributed to β-delayed fission of 200Fr was observed. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]