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From SRAFAP to ARCA and AIDA – developments and implementation of automated aqueous-phase rapid chemistry apparatuses for heavy actinides and transactinides

  • Matthias Schädel EMAIL logo and Yuichiro Nagame
Published/Copyright: April 11, 2019

Abstract

The development of automated rapid chemistry techniques and their application for batch-wise, chromatographic separations of heavy elements in the liquid-phase are outlined. Starting in the mid-1970s with manually performed separations using pressurized liquid-chromatography techniques, this development led to the first version of the Automated Rapid Chemistry Apparatus, ARCA, in the early 1980s. After a breakthrough to a much higher level of automation and miniaturization, the new apparatus ARCA II was built in the late 1980s. Based on it, the Automated Ion-exchange separation apparatus coupled with the Detection system for Alpha spectroscopy, AIDA, became operational in the late 1990s. In the context of technical and technological advancements, this article discusses the successful application of these instruments for (i) the search for superheavy elements, (ii) cross section measurements of actinide elements produced in multi-nucleon transfer reactions with actinide targets, (iii) chemical separation and characterization of the heavy actinides mendelevium, Md, and lawrencium, Lr, and (iv) studies of the transactinide elements rutherfordium, Rf, dubnium, Db, and seaborgium, Sg. Details of the separations are outlined together with the big advancements made over time and the limitations reached. For the transactinide elements, examples are given for their observed chemical behavior; often affected by an interplay between hydrolysis and complex formation. Influenced by relativistic effects, chemical properties of these elements sometimes deviated from those of their lighter homologs in the Periodic Table.


Dedicated to: The memory of Professor Günter Herrmann.


Acknowledgements

We like to thank all scientist and technicians who contributed to the development and scientific success over a period of about 40 years. In place of all of them, we like to mention some of the key persons. Without the work of E. Schimpf the automated chemistry would not have been possible. E.S., together with E. Jäger, took also care of the nuclear chemistry beam lines at the UNILAC. Over the entire period, W. Brüchle and J.V. Kratz were key persons for the success of ARCA operations and the scientific program. B. Haefner’s and W. Schorstein’s contributions in the early phase and B. Schausten’s work in a later phase were essential. Among the many students who worked with ARCA, the work of U. Scherer and P. Zimmermann was crucial in the early phase and the one of W. Paulus in the seaborgium experiments. G. Wirth and K. Sümmerer took care about the detections systems, data evaluation and beam control system. Without targets made by R. Heimann and P. Thörle in Mainz, K.E. Moody and K.E. Gregorich in Berkeley, these experiments would not have been possible. This is also valid for the support from the infrastructure at these institutes. A crucial role played the target lab at the GSI providing large amounts of unique thin foils and the glass blower at Mainz. The scientific expertise, organizational skills, and help of N. Trautmann was indispensable. Many ARCA experiments were performed hand in hand with gas-phase experiments under the leadership of H.W. Gäggeler and his groups from the PSI, Villigen, and the University of Berne. We acknowledge K. Tsukada for his dedication to develop all the systems of AIDA and AIDA II. I. Nishinaka, S. Goto and M. Asai were key researchers for the construction of the fully automated system in AIDA. Y. Kasamatsu’s contribution is highly appreciated for the development of AIDA-II. We like to thank the following members who were/are in the research group for nuclear chemistry of heavy elements, ASRC, JAEA for their contributions in the development and improvement of AIDA and AIDA-II and in conducting experiments with them: K. Akiyama, H. Haba, S. Ichikawa, Y. Ishii, Z. J. Li, M. Sakama, T. K. Sato and A. Toyoshima. The works with AIDA and AIDA-II were supported in part by the JAEA-University Collaboration Research Program and by the Program on the Scientific Cooperation between the JAEA and the GSI in Research and Development in the Field of Ion Beam Application. We like to thank the accelerator crews at GSI’s UNILAC, LBL’s 88-ich cyclotron, PSI’s Philips cyclotron, and the JAEA Tandem Accelerator for providing sometimes very demanding beams.

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Received: 2019-01-10
Accepted: 2019-03-11
Published Online: 2019-04-11
Published in Print: 2019-07-26

©2019 Walter de Gruyter GmbH, Berlin/Boston

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