On Valentine’s day, the lovers of the Test Storage Ring (TSR) at ISOLDE joined expertise in a full day workshop dedicated to study in detail the possible day-one experiments to be done there (see: http://isolde.web.cern.ch/updates/tsrisolde-workshop-14th-february-2014). An anatomy of the proposed experiments and a detailed analysis of the pro and cons were done by the physicists attracted by the potentiallity of this new machine at ISOLDE and the engineers that knew well the performance of the TSR.

The Test Storage Ring at the Max-Planck Institute for Nuclear Physics in Heidelberg, Germany (Image: Max-Planck Institute)

The TSR is a highly performing storage ring in operation since 1988. In its current home at the Max Planck Institute for Nuclear Physics in Heidelberg in Germany, the 55-metre ring circulates beams of heavy stable ions for experiments in atomic and molecular physics and for accelerator studies. The proposal of using it with radioactive ion beams from HIE-ISOLDE was well received and supported by many scientists especially from the international ISOLDE collaboration. A team consisting of some 150 members in 50 countries prepared a feasibility study published in the form of a Technical Design Report in a special topical issue of European Phys. Journal (http://link.springer.com/article/10.1140%2Fepjst%2Fe2012-01599-9).

The opportunities for reactions studies were examined; ISOLDE offers a range of radioactive beams that is unrivalled worldwide. HIE-ISOLDE will cover the ideal energy range for many direct reactions namely energies below and around 10 MeV/u. The addition of the TSR will allow extra cooling of the beams that will provide significant improvement of the beam quality and the beam waste. These two properties are crucial for the planned solenoidal magnetic spectrometer. The science addressed in the study of direct reactions is single-particle behaviour, shell evolution, shape coexistence, collectivity, pairing and reaction of astrophysical interest either by single-nucleon or paired-nucleon transfer reactions.

Beyond the reaction studies, the study of half-life of astrophysical interest such the half-life of 7Be was examined in detail. Using the Schottky noise method the half-life of isomeric states can be determined. The method is ideal for fully stripped ions that can be obtained at ISOLDE up to Z = 40 with the planned upgrade of the EBIS already on-going. The low momentum spread of the TSR will benefit the laser spectroscopic studies of rare isotopes. 

TSR will significantly enhance ISOLDE’s capabilities and open new experimental possibilities in nuclear and atomic physics, scientists and astrophysicists. Following the approval of these plans by CERN’s Research Board, the CERN Council will have to make a final decision.