Studies Of DR Experiments Of Li-like And Be-like Argon Ions At The CSRm

The heavy ion storage ring equipped with electron cooler provides phase-space cooled high quanlity ion beams and low temperature electrons,which greatly improves the energy resolution and the signal-to-noise ratio of recombined ions in dielectronic recombination?DR?experiments,and provides an excellent experimental platform for precision spectroscopy of highly charged ions.This thesis mainly focues on the DR experimental studies of Li-like and Be-like argon at the HIRFL-CSRm.Main results include the following two parts.In the first part,the DR spectrum of lithium like 36Ar15+ion was carefully measured in the energy range 0-35 e V in the c.m.frame,which covers all the ?n=0 DR series of 2s core electron?1s22p1/2 nl and 1s22p3/2 nl?.The obtained longitudinal electron beam temperature was k T| = 0.8 me V and the transverse electron beam temperature was k T^ = 40 me V.The transition energies of 2s1/2?2p1/2 and 2s1/2?2p3/2 are determined to be 31.95 ± 0.05 e V and 35.00 ± 0.08 e V respectively.For a better understanding of the spectrum,a theoretical calculation using the FAC code is performed.The theoretical calculation is in good agreement with the experimental results.In addition,based on the DR experimental results of Li-like 36,40Ar15+ions,we dicussed the isotope shifit measurement with storage ring DR method and gave out the reason why the istope shift between 36,40Ar15+can't be observed from present results.In the second part,based on the calibration DR experiment of Li-like argon,the DR experimental study of Be-like ⁴⁰Ar¹⁴⁺ was carried out.The ?n = 0 transitions of DR?2s2?2s2p?and tielectronic recombination?TR??2s2?2p2?were observed successfully.They account for all resonant recombination of ⁴⁰Ar¹⁴⁺ in the measured energy region 0-60 e V in the c.m.frame.A theoretical calculation using the atomic code AUTOSTRUCTURE by N R Badnell group is performed and the results is in good agreement with the measured spectrum.The plasma rate coefficients was derived by convolving the measured rate coefficients with a Maxwell-averaged electron energy distribution.It is found that TR contributes up to 20%–40% of the total rate for plasmas with temperatures between 1 and 100 e V.