ISOLDE, CERN’s nuclear physics facility started physics the 1st of August. Several experiments have already been completed thanks to the wonderful job done by Magdalena Kowalska, our beam coordinator, the technical CERN team and all the users that worked intensively to produce the best physics possible. Up to 40 more experiments are expected to be scheduled until the end of the year. In the following I will mention a few examples to give a taste of the physics accomplishments of the first six weeks of beam time.

The very first experimental run was greeted with a fantastic atmosphere and a real buzz in the air. Samples of lanthanides ¹⁴⁹Tb and ¹⁵⁵Tb were collected and shipped to PSI Villigen, Switzerland and ¹⁴⁰Nd to DTU Riso, Denmark. The¹⁴⁹Tb nucleus is a promising isotope for targeted alpha therapy.The ¹⁵⁵Tb and ¹⁴⁰Nd nuclei studies aim both at a better understanding of the therapeutic effects of short-range Auger electrons. This experience is part of a program initiated in 2012 which aim to identify chemical elements with suitable isotopes for diagnosis and therapy. The ¹⁴⁹Tb isotope, a promising vector for alpha therapy, is now used in a long-term study on mice in order to determine the safe activity limit that can be administered. Six mice were injected with 2.5 MBq¹⁴⁹Tb-folate each. The aim is to investigate potential damage to the kidneys in a long-term experiment spanning over 8 months. Another group of two mice were injected with a different amount of ¹⁴⁹Tb-folate to check the dose effect.

Fig 1. The ISOLTRAP setup has been refurbished during the LS1. 

In parallel to on-going work on the HIE-ISOLDE project, the ISOLTRAP setup had been refurbished during LS1. The goal of the first measurements of ISOLTRAP was the mass determination of very neutron-rich, short-lived cadmium isotopes. The masses of these isotopes are important in the context of nuclear astrophysics addressing the question of how heavy elements were created (nucleosynthesis). High-precision mass data are required as input for astrophysical models describing possible nucleosynthesis processes. Before, little was known on the exotic isotopes of interest, ^129-131Cd. It was only last year when the laser-spectroscopy setup COLLAPS at ISOLDE determined electromagnetic moments of two states in ¹²⁹Cd, that of the ground state and an isomeric state, i.e. a long-lived excited state. Yet, the mass of these two states remained undetermined. The mass of ¹³⁰Cd had been determined also at ISOLDE through beta-decay studies several years ago but with insufficient accuracy. The ISOLTRAP Penning-trap mass spectrometer succeeded in the mass determination of ^129-131Cd with unprecedented precision, thus providing potentially crucial data in the quest for a possible birthplace of the heavy elements.

The first experiment in the new ISOLDE permanent experimental station, IDS, ISOLDE Decay Station, was dedicated to high-precision measurements of the beta-decay of neutron rich nuclei around the N=126 neutron magic number. The main physics focus of this experiment was to identify, weakly populated ‘core breaking’ and collective octupole-coupled excited nuclear states in the N=126 magic nucleus ²⁰⁷Tl. The decay of the ²⁰⁷Tl daughter is also of general interest as it is the final decay of the naturally occurring radiation, starting from the primordial radionuclide ²³⁵U. This decay could also be used as an experimental monitor for enriched nuclear fuel and also has the potential to be used as a radiopharmaceutical tracer in the decay of the decay chain member ²²³Ra, which is now being used in RaCl₂ chemical treatment for the palliative treatment of metastesized prostate cancers.

Finally, I will mention an experiment that just completed its run in week 38. It was dedicatedto the study of the atomic hyperfine structure and isotope shift of as many as 24 astatine isotopes and 9 isomers from ¹⁹⁴At to ²²¹At. These data will give direct access to the nature of the nuclear ground-state properties of these isotopes, including their deformation. Dramatic features have already been seen in the online analysis and exciting results are to be expected with the final analysis.Another important aspect of this experiment was the synergy between the RILIS team (CERN EN-STI) and the Windmill and ISOLTRAP collaborations (CERN PH-UIS). The lasers from RILIS were used not only to produce the astatine isotopes, but also to probe the optical transition revealing the hyperfine structure and the isotope shift. Meanwhile, the ionisation rate was monitored either directly on a Faraday cup, via alpha-decay spectroscopy at the Windmill setup equipped with silicon and germanium detectors, or using the ISOLTRAP Multi-Reflection Time-of-Flight mass spectrometer MR-ToF. The complementarity between the different devices allows to gain in sensitivity allowing measurements ina wide rangeof 8 orders of magnitude in production rates and half-lives. Furthermore, the Windmill can analyse their spectra to refine the study of the decays, benefiting from beams of unprecedented purity. Meanwhile, ISOLTRAP is steadily building up data on the masses of the astatine isotopes with the MR-ToF and will provide the first direct measurements for these isotopes. An example of this combined effort is given in figure 1.

In summary the ISOLDE facility is fully functioning, several successful results already being obtained and many more to come before December when we will celebrate the 50 anniversary of the approval of ISOLDE.  With all these years of operation ISOLDE remains the World pioneer ISOL-installation both at the level of designing new devices and production of frontier physics.