Sympathetic cooling of radioactive 26mAl to test the standard model
The standard model of particle physics is our most successful physical theory to date, describing three of the four fundamental forces in the universe with unprecedented accuracy. Testing the validity of the standard model is one of the core activities within contemporary physics research. One cornerstone uses the measurement of beta-decay properties to test the unitarity of the so-called Cabibbo-Kobayashi-Maskawa mixing matrix, which contains information on the strength of the weak nuclear interaction. In this project, we seek to improve the constraints on the unitarity of this matrix, thus testing the validity of the standard model, through a significantly more precise measurement of the Q-value of the beta-decay of the isomeric state of the isotope 26Al. We aim to achieve at least one order of magnitude improvement in precision, which we will achieve by sympathetically cooling the 26mAl isotopes to a few kelvin using laser-cooled 40Ca coolant ions. In doing so, the precision of Penning-trap mass measurements will be improved dramatically. We will design, construct and test a linear radiofrequency Paul trap, optimized for efficient injection and cooling of radioactive isotopes, as well as the required coolant ions (40Ca in this case). This device will be developed at KU Leuven, and will then be moved to the Ion-Guide Separator On-Line facility in the accelerator laboratory in Jyväskylä, Finland, where the Q-value measurements will take place.