Seminarium Optyczne

The scientific aim of talk will be presentation of the results of investigation the structure of selected elements: chromium, manganese andthorium, in terms of their applications in optical atomic and nuclear clocks. Research work was carried out at the Poznań University ofTechnology and at PTB Braunschweig, Germany.One of the tasks was to obtain a possibly complete description of the electronic energy structure of the atoms of selected elements with an open3d shell - chromium and manganese [H1-H8], which could form the basis of an effective search for electronic level systems with specificproperties necessary for applications in quantum engineering and metrology, in particular for optical atomic clocks. The remaining part of thepresentation will include the works related to the pioneering optical nuclear clock project, based on the transition between the ground and theexcited (isomer) state transition in 229 thorium nucleus, which was developed in cooperation with the Prof. E. Peik’s research group from PTB(Germany), leading in this field.In the case of the chromium atom, comprehensive studies of the hyperfine structure will be presented, performed by laser spectroscopy on anatomic beam apparatus: the methods of double optical-microwave resonance ABMR-LIRF (Atomic Beam Magnetic Resonance detected byLaser Induced Resonance Fluorescence) and LIF (Laser Induced Fluorescence) [H1-H3]. Based on the collected experimental results and thedata from literature sources, a semi-empirical analysis of the electronic structure of the chromium atom was carried out. This allowed to proposethe use of the forbidden transition between selected levels of the chromium atom as a possible optical clock transition along with possibleschemes of its detection [H4].For the manganese atom, the results of experimental studies of the hyperfine structure will be presented, performed with the use of the LIFmethod on an atomic beam [H5,H6] and in a hollow cathode lamp [H8]. In this case, the theoretical semi-empirical analysis of the structure ofthis element in terms of radiative parameters (such as oscillator strengths, transition probabilities and the levels’ lifetimes) allowed to proposethree possible optical clock transitions and possible cooling schemes [H7].The presentation will also show the basic assumptions regarding the implementation of an optical nuclear clock, both in research on trappedTh+,Th2+, Th3+ ions in linear traps [H9], as well as the concept of its implementation based on a crystal volume-doped with Th4+ ions, (e.g. CaF2:Th4+), or in a simpler version - a surface-doped crystal [H10].H1 A. Krzykowski, P. Głowacki Experimental study of radio frequency power broadening in ABMR-LIRF method, Elektronika 6: 31-34 (2011), (IF = —, MNiSW8 pkt.) https://www.sigma-not.plH2 A. Krzykowski, P. Głowacki, A. Jarosz Precise measurements of the hyperfine structure of the levels belonging to the terms 3d54s 5G and 5P in Cr(I), ActaPhys. Pol. A, 122, p. 78-81 (2012), (IF = 0.444, MNiSW 15 pkt.) doi: 10.12693/APhysPolA. 122.78H3 P. Głowacki, A. Krzykowski, A. Jarosz Investigation of the hyperfine structure of electronic levels in chromium atom, Eur. Phys. J. Special Topics 222, 2345-2351 (2013), (IF=1.862, MNiSW 30 pkt.) doi: 10.1140/epjst/e2013- 02015-xH4 P. Głowacki, D. Stefańska, M. Elantkowska, J. Ruczkowski Proposed clock transition in atomic chromium and the possible detection schemes Journal ofQuantitative Spectroscopy and Radiative Transfer 291, 108331 (2022), (IF = 2.342, MEiN* 100 pkt.) doi: 10.1016/j.jqsrt.2022.108331H5 P. Głowacki, D. Stefańska, M. Elantkowska, J. Ruczkowski Hyperfine structure studies of the electronic levels of the manganese atom. I. Even-parity levelsystem Journal of Quantitative Spectroscopy and Radiative Transfer 249, 107013 (2020), (IF = 2.468, MEiN∗ 100 pkt.) doi: 10.1016/j.jqsrt.2020.107013H6 P. Głowacki, D. Stefańska, J. Ruczkowski, M. Elantkowska Hyperfine structure studies of the electronic levels of the manganese atom. II. Odd-parity levelsystem Journal of Quantitative Spectroscopy and Radiative Transfer 253, 107138 (2020), (IF = 2.468, MEiN∗ 100 pkt.) doi: 10.1016/j.jqsrt.2020.107138