This book presents a cohesive overview of spectroscopy and lifetimes of multiply charged ions using ion beams and ion traps. While these techniques are seemingly disparate, the author’s experience in both fields allows for a unique perspective that demonstrates their natural interconnections and the shared physical principles that underpin both techniques. Drawing on extensive experience across major laboratories, the author offers an accessible guide to how instrumental developments from beam foil methods to electron beam ion traps enable precision measurements of excitation processes and atomic lifetimes. The discussion emphasizes how technical conditions, vacuum requirements, excitation environments, and diagnostic capabilities influence the interpretation of spectroscopic data. Blending scientific explanation with historical and personal insight, the technical exposition is interspersed with stories which show the human side of the subject and the role of community in its development. Designed for researchers and graduate students in atomic and plasma physics, it provides a clear and insightful conceptual framework for spectroscopy in general, a wealth of historical information, and references to the vast number of spectra that have been measured with beam-foil and ion trap methods.

Elmar Träbert studied physics at Ruhr-Universität Bochum (Germany). His diploma thesis dealt with the optical emission inside a detector used for nuclear physics. For his PhD thesis he switched to beam-foil spectroscopy, an atomic physics tool employing a fast ion beam as is often provided for nuclear physics experiments. The Bochum Dynamitron tandem accelerator laboratory proved to be a superb environment for that work. Further atomic physics experiments with fast ion beams led him to heavy-ion accelerator laboratories at Oxford (UK), Brookhaven (NY, USA), GSI Darmstadt (D), Stockholm (S), Tucson (AZ, USA), Toledo (OH, USA), Argonne (IL, USA), Daresbury (UK), Liège (B) and many times to the heavy-ion storage ring TSR at Heidelberg (D). He gathered ion trapping experience at the Harvard-Smithsonian Center for Astrophysics, spent time at NIST Gaithersburg (MD, USA), and paid very many research visits to the LLNL electron beam ion trap at Livermore (CA, USA).