Scientists observe one of the heaviest elements

Scientists from the University of Liverpool have been part of an international team that have observed chemical element 114, one of the heaviest elements created to date.

The creation of Element 114 was complex and required the use of dedicated particle accelerators.  The innovative new setup TASCA (TransActinide Separator and Chemistry Apparatus), which was developed recently in Germany, was used by scientists to conduct the experiment.  To date, only two other research centres, in the USA and Russia, have achieved this feat. The aim of future experiments using TASCA is to advance to yet heavier elements and possibly to discover new elements beyond element 118, the heaviest element known.

The element’s atomic number (the number of protons in the atomic nucleus) is 114, hence its preliminary name “element 114″.  Its atomic number corresponds to the sum of those of the reacting elements: calcium with 20 and plutonium with 94 protons.

Dr Rolf-Dietmar Herzberg, from the Department of Physics, was part of an international team based at GSI Helmholtzzentrum fur Schwerionenforschung (GSI) in Germany which was led by scientists from GSI, the Johannes Gutenberg University Mainz and the Technische Universití¤t Mí¼nche and included researchers from Liverpool (UK), Berkeley (USA), Jyví¤skylí¤ (Finland), Kolkata (India), Lund (Sweden), Oslo (Norway) und Warsaw (Poland).

With the new TASCA setup, the international research team observed 13 atoms of element 114 during the course of their four week long experiment. Despite being a small number of atoms, this corresponds to the highest ever measured production rate for element 114. It paves the way for future in-depth chemical, atomic, and nuclear physics studies. Based on the radiation emitted during the element’s decay, the scientists were able to identify two different isotopes of element 114 with the mass numbers 288 and 289. The measured half-lives are in the region of one second.

Christoph Dí¼llmann, head of collaboration at GSI, said:  “TASCA is currently the world’s most efficient system for detecting superheavy elements produced with particle accelerators. This high efficiency is the key to future experiments, where we will also conduct chemical analyses of superheavy elements in the vicinity of element 114, to determine their correct position in the periodic table of the elements”

Using the 120-meter long GSI particle accelerator, the scientists fired charged calcium atoms (called calcium ions) onto a plutonium-coated foil. In the course of the experiments, a calcium and a plutonium nucleus underwent fusion to form a nucleus of the new element.

The gas-filled separator TASCA separated the atoms produced by the accelerator with high selectivity from other reaction products. The atoms of element 114 then implanted into a special semiconductor detector, where they were subsequently identified based on the radiation emitted during their decay.

Notes to editors:

1.  The University of Liverpool is a member of the Russell Group of leading research-intensive institutions in the UK. It attracts collaborative and contract research commissions from a wide range of national and international organisations valued at more than £98 million annually.

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