Nuclear charge radii of Al and Si from elastic electron scattering between 25 and 60 MeV

Elastic electron scattering cross sections of²⁷Al and Si (natural isotopic mixture) have been measured relative to carbon. The rms charge radiiR _m , deduced with partial wave calculations, are (3.01±0.05) fm for²⁷Al and (3.06±0.05) fm for Si, in good agreement with results from muonic X-ray energies. The values given are those for a Fermi charge distribution with skin thickness 2.5 fm; harmonic oscillator shell model distributions yield radii smaller by 0.03 fm. The ratioR _m (²⁷Al)/R_m(Si) is 0.984±0.016.     

Nuclear charge radii from optical spectroscopy

The changes of the mean-square nuclear charge radii have been re-evaluated [3] on an equivalent basis, using all available data from optical spectroscopy. The steps of evaluation are discussed and the results are presented in a number of diagrams, showing the course of 〈r ²〉 fromN=20 toN=152 and showing details of δ〈r ²〉     

Total electron scattering cross-sections for carbon monoxide at low electron energies

Absolute total electron scattering cross-sections for carbon monoxide have been measured at low electron energies using a photoelectron source. The measurements have been carried out at 22 electron energies varying from 0.73 to 9.14 eV with an accuracy of ±3%. The cross-sections obtained in the present experiment have been compared with other measurements and theoretical computations.     

Total electron scattering cross-sections for nitrous oxide at low electron energies

Absolute total electron scattering cross sections for nitrous oxide have been measured at low electron energies using a photoelectron source. The measurements have been carried out at 19 electron energies varying from 0.73–9.14 eV with an accuracy of ±3%. The cross sections obtained in the present experiment have been compared with other measurements.     

Charge radii from lattice relative charge distributions

Electromagnetic charge radii values are extracted from relative charge distribution data for pseudoscalars using lattice QCD techniques. This is done with Wilson fermions and SU(2) color at five values of the hopping parameter.     

Total electron scattering cross sections for carbon dioxide at low electron energies

Absolute total electron scattering cross sections for carbon dioxide have been measured at low electron energies using a photoelectron source. The measurements have been carried out at 27 electron energies varying from 0.91–9.14 eV with an accuracy of ±3%. The cross sections obtained in the present experiment have been compared with other measurements and theoretical computations.     

Precise nuclear radii from electron scattering

Independent empirical information on the properties of nuclear wave functions at large radii improves the precision of radii deduced from elastic electron scattering by a factor of 3. Using these radii to predict measured muonic atoms transition energies allows a more stringent test of the QED vacuum polarization effect.     

Nuclear charge radii of Sc,V, Fe,Co, Ni,Cu and Zn from elastic electron scattering at 60 MeV

Elastic electron scattering cross sections have been measured at 60 MeV for scattering angles between 45 and 153 degrees relative to⁴⁶Ti (for⁴⁵Sc),⁵⁰Ti (for⁵¹V) and¹²C (for the other nuclei). The following rms radii (in fm) have been deduced with a Fermi-type charge distribution (skin thickness 2.5 fm):⁴⁵Sc: 3.52(9);⁵¹V:3.62 (9); Fe: 3.71 (11);⁵⁹Co: 3.77 (5); Ni: 3.78 (8); Cu: 3.85 (5); Zn: 3.90 (5). The present uncertainty of the rms radius of¹²C increases the errors given by 0.01 fm. The rms radius differences 0.04 (5) fm for⁴⁶Ti-⁴⁵Sc and 0.06 (5) for⁵¹V-⁵⁰Ti were measured directly.     

Inclusive measurements of pionic double charge exchange on 3He at low energies

Using the CHAOS spectrometer at TRIUMF pion momentum spectra and angular distributions were measured for the ³He(π⁻,π⁺) reaction at incident energies from 65 to 120 MeV and total cross sections were deduced. The data are compared to Monte Carlo simulations for the conventional reaction process as well as to predictions for the production of the hypothetical πNN resonance d′ with and without collision damping.     

Nuclear charge radii of molybdenum fission fragments

Radioisotopes of molybdenum have been studied using laser spectroscopy techniques at the IGISOL facility, University of Jyväskylä. Differences in nuclear charge radii have been determined for neutron deficient isotopes ^90,91Mo and neutron rich isotopes ^{102–106,108}Mo (and all stable isotopes). A smooth transition in the mean square charge radii is observed as the neutron number increases with no sudden shape change observed in the region around N=60$N=60$. As N   increases, the nuclear deformation appears to go beyond a maximum and a fall off at N=66$N=66$ is observed. The magnetic moments of the odd isotopes ^91,103,105Mo are also determined.     

Coulomb effects in polarization transfer in elastic antiproton and proton electron scattering at low energies

The influence of Coulomb distortion on the polarization transfer in elastic proton and antiproton electron scattering at low energies is calculated in a distorted-wave Born approximation. For antiproton electron scattering Coulomb effects reduce substantially the polarization transfer cross-section compared to the plane-wave Born approximation, whereas for proton electron scattering they lead to a dramatic increase for kinetic proton lab energies below about 20keV.     

Total cross sections scattering at of positron-sodium low energies

A new calculation for the total cross section of positron-sodium scattering is performed in an energy range down to a few tenths of one electron volt using the coupled-channel optical method.The ionization continuum and the positronium formation channels are included via an equivalent-local complex potential.The role played by the break-up and rearrangement processes in the low energy positron-sodium scattering is also investigated.The total scattering cross section is reported and compared with the available theoretical and experimental data.     

Nuclear levels in43Sc at low excitation energies

Properties of levels up to 3.5 MeV in⁴³Sc were studied using⁴⁰Ca (α, p)⁴³Sc and⁴⁰Ca(α, pγ)⁴³Sc reactions atE _α =12 MeV. Level energies, branching ratios, mean lifetimes, spins and mixing ratios were obtained for a number of levels. Relevant results are compared with many-particle shell-model predictions.     

Prospects for electron cooling of antiprotons at low energies

The motivation of using electron cooling in low-energy antiproton storage rings and the expected cooling performance are discussed. Results obtained recently, during the first operation of electron cooling in LEAR at CERN with a 50 MeV proton beam, are summarized, concerning in particular the equilibrium beam properties, the recombination between cooling electrons and cooled protons, and the deceleartion of acceleration of protons by friction in the electron beam. Conclusions are drawn for the formation of antihydrogen with the cooled antiproton beam, and for the deceleration of antiprotons to energies close to or below 1 MeV.     

Experimental determinations of electron stopping power at low energies

Abstract

An accurate knowledge of electron stopping power is important for calculations and simulations of electron beam interactions with solids especially in the low energy region (< 10 keV). This paper describes a simplified and rapid experimental procedure using based on electron energy loss spectroscopy which permits accurate stopping power determinations to be made from any material which can be observed in a transmission electron microscope. It is demonstrated that the stopping power and oscillator strength data so generated is in good agreement with other measurements and theoretical predictions. The technique is now being applied to a wide variety of materials of semiconductor interest.     

Virtual Compton scattering at low energies with a positron beam

The European Physical Journal A - Using a transport model that includes a first-order chiral phase transition between the partonic and the hadronic matter, we study the development of density...