The HIE-ISOLDE-project in Cern.

With this project, Flemish researchers from the universities of Leuven and Gent aim to use the unique set of radioactive ion beams which are and will become available at the ISOLDE project in CERN for studies in nuclear physics, nuclear astrophysics, fundamental interactions and solid-state physics using nuclear methods. This covers nuclear structure research of exotic nuclei with unusual proton to neutron ratio, determination of nuclear properties of crucial relevance for nucleosynthesis, the search for new physics beyond the Standard Model through weak- interaction studies in the low-energy sector and the characterization of dilute probes in low-dimensional systems. A major upgrade of the present ISOLDE facility, called High Intensity and Energy ISOLDE (HIE-ISOLDE) is now proposed. The present Big Science proposal aims to consolidate the position of the Flemish researchers in ISOLDE by a vigorously participation in HIE-ISOLDE The HIE-ISOLDE project is a major upgrade to the existing REX accelerator facility at ISOLDE with the objective to provide radioactive beams up to 10 MeV/u with an intermediate step at 5.5 MeV/u. The ambition is to make all isotopes produced at ISOLDE (>800) available as post accelerated beams. The beam quality will be much improved for ISOLDE users with the installation of a RFQ cooler, a new Resonant Laser ionization System and a renovated High Resolution Mass separator. New isotopes will be made available through target and ion source development. The driver intensity will be increased (5x), with a first increase coming from a faster cycling of the PS Booster and a later increase coming from the new Linac-4. Justification The INTC NUPAC meeting in 2005 made specific recommendations for an upgrade of ISOLDE [1]. The technical options for an upgrade was studied by the AB department during spring 2006 and presented to Research Board in June 2006 [2]. The standing group for the upgrade of ISOLDE [3] which is reporting to the INTC, has in its meeting 5th October 2006 proposed priorities for the project. In order to maintain momentum of the project, and ensure that ISOLDE keeps its leadership in the field of radioactive beam science, the first priority is to increase the energy to 5.5 MeV/u (phase 1) and some beam quality improvements. The increase in beam energy has particular significance following the recent demonstration of successful charge breeding of Ta, U ions. This breakthrough effectively doubles the potential number of beams available accelerated, provided that energy increases from 3 to > 5 MeV/u. A further major increase in physics reach will be achieved in phase 2, with the intensity increase and improvements in the beam characteristics, and increase in energy to 10 MeV/u. If the PS Booster is replaced by the SPL, we will benefit enormously from the factor of 100 increase in power on the primary target and the low duty cycle characteristics of the primary beam, and that will enable a physics programme similar to that envisaged for EURISOL.

Keywords:Isolde, Cern, Radioactive Ion Beams, Nuclear physics

Disciplines:Applied mathematics in specific fields, Other engineering and technology, Nuclear physics, Classical physics, Elementary particle and high energy physics, Other physical sciences