Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for 26 O, 26 F, 26 Ne, 26 Na, 26 Mg, 26 Al, 26 Si, 26 P, and 26 S. This evaluation for A=26 supersedes the earlier one by P. M. Endt (1998En04) and updates for some nuclides in ENSDF. Highlights of this evaluation are the following: This evaluation includes search results for 26 S nuclide and its proton-decay mode (2011Fo08). An isomeric state (2.2 ms) in 26 F has been discovered by 2013Le03. The state is proposed at 643.4 keV 1 from γ-ray measurements. Internal-transition and beta-decay branches for the state are also determined. New excited levels in 26 Ne have been identified from 26 F βdecay (2.2 ms). For some 26 Si resonance states conflicting spin-parity assignments exist in the literature. These are identified by footnotes. 2015Do07 (3 He,nγ) propose the first 0+ state above proton separation energy at an excitation energy of 5890 keV and suggested for additional independent measurements to confirm or refute the existence of 5946 keV 4. 2016Ch09 consider 5946 keV level as a distinct excited state in their reanalysis of the literature data with possible spin-parity assignment of 0+ or 4+ This evaluation also includes discovery of an isomeric state, at 164.1 keV 1, in 26 P by 2014NiZZ.

Abstract. The Miniball germanium detector array has been operational at the REX (Radioactive ion beam EXperiment) post accelerator at the Isotope Separator On-Line facility ISOLDE at CERN since 2001. During the last decade, a series of successful Coulomb excitation and transfer reaction studies have been performed with this array, utilizing the unique and high-quality radioactive ion beams which are available at ISOLDE. In this article, an overview is given of the technical details of the full Miniball setup, including a description of the γ-ray and particle detectors, beam monitoring devices and methods to deal with beam contamination. The specific timing properties of the REX-ISOLDE facility are highlighted to indicate the sensitivity that can be achieved with the full Miniball setup. The article is finalized with a summary of some physics highlights at REX-ISOLDE and the utilization of the Miniball germanium detectors at other facilities.

The first excited 2 state of the unstable isotope 110 Sn has been studied in safe Coulomb excitation at 2:82 MeV=u using the MINIBALL array at the REX-ISOLDE post accelerator at CERN. This is the first measurement of the reduced transition probability of this state using this method for a neutron deficient Sn isotope. The strength of the approach lies in the excellent peak-to-background ratio that is achieved. The extracted reduced transition probability, BE2 : 0 ! 2 0:220 0:022e 2 b 2 , strengthens the observation of the evolution of the BE2 values of neutron deficient Sn isotopes that was observed recently in intermediate-energy Coulomb excitation of 108 Sn. It implies that the trend of these reduced transition probabilities in the even-even Sn isotopes is not symmetric with respect to the midshell mass number A 116 as 100 Sn is approached. DOI: 10.1103/PhysRevLett.98.172501 PACS numbers: 23.20.Js, 21.60.Cs, 25.70.De, 27.60.+j Substantial interest has recently arisen in the shell structure of atomic nuclei with only a few nucleons outside the double shell closure at 100 Sn. As an example, a series of experiments aiming at isotopes in this region has been carried out using fusion-evaporation reactions in the recent past [1]. With the advent of radioactive ion beams these studies are now taken further using sub-barrier and intermediate-energy Coulomb excitation [2,3]. In this Letter we present the only sub-barrier or ''safe'' Coulomb excitation experiment in this region to date. The study of the reduced transition probability -the BE2-of the first excited 2 state in an even-even nucleus gives a direct handle on the collectivity of that state. It can thus be used to measure systematic changes in the strengths of shell gaps. The general motivation for this kind of study goes back to our incomplete knowledge of the mechanisms that govern shell formation and their implications for the structure of nuclei far from stability. It is well known that a strong spinorbit force was introduced into the nuclear shell-model on Fermi's suggestion by Goeppert Mayer [4] and independently by Haxel, Jensen, and Suess [4] to explain the observed shell gaps. However, these papers were substantially predated by the consideration of a nuclear spin-orbit force by Inglis [5] who noted that the relativistic Thomas term which arises as a consequence of the noncommutation of Lorentz transformations should act also in atomic nuclei. This term, given by the vector product of the velocity and acceleration of the bound nucleon, gives rise to nuclear LS coupling, a result which can be derived from the Dirac equation [6]. In this picture, the acceleration is proportional to the derivative of the potential experienced by the bound particle, a notion still used in mean-field approaches today. As a consequence, the splitting of the shell gaps becomes density dependent and may change with the PRL 98,