Mapping the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>N</mml:mi><mml:mo>=</mml:mo><mml:mn>40</mml:mn></mml:mrow></mml:math> island of inversion: Precision mass measurements of neutron-rich Fe isotopes
W. S. Porter, B. Ashrafkhani, J. Bergmann, C. M. Brown, T. Brunner, J. D. Cardona, D. Curien, I. Dedes, T. Dickel, J. Dudek, E. Dunling, G. Gwinner, Z. Hockenbery, J. D. Holt, C. Hornung, C. Izzo, Andrew Jacobs, A. Javaji, B. Kootte, Gabriella Kripkó-Koncz, E. M. Lykiardopoulou, T. Miyagi, Ish Mukul, T. Murböck, W. R. Plaß, M. P. Reiter, Jon Ringuette, C. Scheidenberger, R. Silwal, C. Walls, H. L. Wang, Y. Wang, Jie Yang, J. Dilling, A. A. Kwiatkowski
Abstract
The authors report precise measurements of the masses of neutron-rich iron isotopes with $A=63$ to 70 with the multiple-reflection time-of-flight mass spectrometer of the ion trap facility TITAN at TRIUMF. This work constitutes the first use of Fe beams at an ISOL facility, owing in part to a novel laser ionization scheme. A newly discovered isomeric state in ${}^{69}$Fe, together with the new masses, benchmarks state-of-the-art nuclear structure models in a region of rapid structural change.