DIELECTRONIC RECOMBINATION OF BORON-LIKE ARGON

We present measurements and calculations of Delta n=0 dielectronic rec ombination resonances of boronlike argon between 0.2 and 6 eV. A stora ge ring equipped with an electron cooler was used for the measurements . Methods employed to reduce the electron energy distribution and impr ove the accuracy of resonance energy measurements have yielded an ener gy resolution of 30 meV full width at half maximum at low energies, an d an energy uncertainty better than 30 meV. The high energy resolution results from the use of an adiabatic expansion technique to reduce th e transverse electron energy distribution. The improved accuracy in en ergy determinations is achieved through the inclusion of variations in the ion velocity, which occur during scans of the electron velocity, in the relative velocity transformations. Calculations of the resonanc e strengths and energies were made using two different methods, multic onfiguration Dirac-Fock and multiconfiguration Breit-Pauli approximati ons. A comparison of the experimental data to the calculations shows f air agreement in both the spectral features and integrated intensities above 3 eV. However, poor agreement is found below 3 eV.