Measurement of the wavelength of the {Lyman-α_1tn [Lyman-alpha-1] transition of _1hn2_1hn0_1hn8Pb_1hn8_1hn1_1hn+ using FOCAL spectrometers [Elektronische Ressource] / presented by Shyamal Chatterjee

Dissertationsubmitted to theCombined Faculties for the Natural Sciences and for Mathematicsof the Ruperto-Carola University of Heidelberg, Germanyfor the degree ofDoctor of Natural Sciencespresented byShyamal Chatterjee, MScborn in: Burdwan, IndiaOral examination: 17.01.2007Measurement of the Wavelength of the208 81+Lyman-α Transition of Pb Using1FOCAL SpectrometersReferees: Prof. Dr. Dieter LiesenProf. Dr. Joachim Ullrich208 81+Measurement oftheWavelengthoftheLyman-α Transitionof Pb1Using FOCAL Spectrometers - The goal ofthe experimental study is the de-termination of the 1s Lamb shift of a one-electron, very heavy ion with highprecision by an accurate spectroscopy of the corresponding Lyman-α transitions.Unlike low-Z systems the quantum electrodynamical (QED) calculations usingperturbation theory based on the expansion parameter Zα are no longer applica-ble for high Z systems and therefore all orders ofZα are included in the calcula-tions. The present accuracy of the calculations is of the order of 1 eV. Thus themeasurements ofthe Lyman-α transitions aimtoachieve anuncertainty, which issensitive to 1 eV or below. Such accurate measurements require high resolutionin the techniques of x-ray spectroscopy. For this purpose a couple of ”FOcusingCompensated Asymmetry Laue (FOCAL)” spectrometers has been developed atGSIandthey have beenemployed inthe firstproductionruninMarch 2006.