Special Universe Talk: Understanding the Universe, one rare isotope at a time

by Jens Dilling (TRIUMF, U British Columbia)

Thursday 2 Aug 2012, 14:30 → 16:00 Europe/Berlin

Universe Cluster (seminar room basement) (Universe Cluster, Garching)

Many of the remaining big questions in understanding the universe, such as how and where the chemical elements in the universe are created, the life and death of stars, or the nature of neutrinos are intimately related to our fundamental understanding of the atomic nucleus. Progress in nuclear theory as well as the advent of rare-isotope beam facilities are key ingredient to getting closer to answering these questions. Rare isotopes are typically only generated in stars, but become more and more accessible are dedicated rare-isotopes facilities around the world. At present one of the premier facility for rare isotopes is the ISAC complex at TRIUMF, Vancouver. There isotopes are produced, however often only in minuscule quantities, and with half-lives as short as few ms, hence the name rare. To overcome the obstacles of rare isotopes and extract information about the atoms and their fundamental interactions dedicated instruments are required. We have developed recently very sensitive and fast methods using ion trap techniques at TITAN (TRIUMF’s Ion Trap of Atomic and Nuclear science). At TITAN we are able to measure masses, using one single ion in as short as 8ms with 10ppb precision, breaking a world-record for precision mass spectroscopy. Using this, we are able to probe into the world of so-called nuclear halos. Teetering on the edge of nuclear stability, the properties of halo nuclei have long been recognized as one of the most stringent tests of our understanding of the strong force. Nuclear halos are an exotic form of nuclear matter that continues to defy the considerable scientific efforts focused upon them in the last two decades. The example of 11Li (discover 25 years ago at Berkeley) belongs to a special category of halos called Borromean, which allows one in a very sensitive way to shed light on the fundamental interactions at work inside nuclei, in particular 3-body forces. This talk will be a report on theses measurements and how they relate to answering the big questions. An overview of the ISAC facility and the physics program is given.