Spectroscopy Measurement And Deceleration Of Highly Charged Nickel Ions

Highly Charged Ions(HCIs)are candidates for the next generation of optical clocks.Compared with neutral atoms or single charged ions,the radius of the electron cloud of HCIs is smaller because of the stronger attraction of the larger effective nuclear charge.Therefore,clock transitions of HCIs are immune to the environmental perturbations inherently,and suitable for building optical clocks whose uncertainty is on the order of 10-19 or even lower.Besides,the clock transitions of HCIs tend to be more sensitive to the variation of the fine structure constant ?.The optical clocks based on HCIs are promising tools to test the temporal variation of a,to explore new physics beyond the standard physics model.Experimentally,the cooperative group of Max-Planck-Institut fur Kernphysik(MPIK)and Physikalisch-Technische Bundesanstalt(PTB)in Germany had trapped and sympathetically cooled 40Ar13+and probed its magnetic dipole(M1)optical transition by quantum-logic spectroscopy recently.Nevertheless,the research of HCIs optical clocks in China just started.Beginning with the cooperation between Innovation Academy for Precision Measurement Science and Technology of Chinese Academy of Sciences and Fudan University,this thesis carried out the first domestic research works of building the HCIs optical clocks based on highly charged nickel(Ni)ions.The main works are as follows:1.In order to build HCIs optical clocks,HCIs need to be produced,decelerated,and cooled.An apparatus for HCIs optical clocks was built,which consists of an HCIs source—a high-temperature superconducting compact electron beam ion trap(Shanghai-Wuhan Electron Beam Ion Trap,SW-EBIT),an HCIs beamline,and a linear ion trap.In the tests,SW-EBIT's electron-beam current was 0-10 mA,electron-beam energy was 30-4000 eV,the HCIs-optical-clocks candidate ions of Ni11+,Ni12+,Ni14+,58Ni12+ions could be selected and decelerated by the HCIs beamline.2.The wavelength accuracies in the NIST database of the clock transitions of the candidate highly charged Ni ions are too low for the start of quantum logic spectroscopy.This work adopted a conjugated observation and calibration scheme,used the S W-EBIT and a spectrograph,measured the emission spectra of the four M1 clock transitions of these candidate Ni ions and indirectly measured the wavelength of one electric quadrupole(E2)clock transition.The accuracy of the measured wavelengths reaches the magnitude of ppm,which is 1-2 orders of magnitude higher than the accuracy of the results in NIST database and narrows the wavelength range for precision laser spectroscopy in future.3.Based on the method of time-of-flight spectra,pulse drift tube and deceleration electrostatic lens,using the HCIs beamline,the 58Ni12+ ions were selected,and the average kinetic energy of 58Ni12+ion was decelerated(reduced)from 678.2(3)qV(where q is the ion charge)to 2.0(3)qV,and the kinetic energy broadening was compressed from 11.4(4)qV to 1.8(3)qV.The production rate of the decelerated 58Ni12+ions was?4000 s-1.This work laid the foundation for the re-trapping of highly charged Ni ions in the linear ion trap.In the works of this thesis,the apparatus for HCIs optical clocks was built,the wavelengths of the clock transitions of the candidate highly charged Ni ions were measured preliminarily,and the Ni ions were decelerated,which laid the foundation for the follow-up research works of HCIs optical clocks.