A direct measurement of the 17O(a,g) 21Ne cross section

Nuclear astrophysics is one of the many applications of nuclear physics and arguably one of the most exciting. It tries to explain where all the elements around us, the oxygen in the air, the iron in our blood, the silicon in computer chips, come from. Where and how were they formed? On top of this, nuclear astrophysics tries to understand how nuclear reactions affect the life and death of all stars. How do such tiny things influence such massive objects as stars? Most stars get their energy by burning stable elements, such as the carbon and oxygen we are familiar with, over long periods of time. The energy is produced by nuclear reactions, turning one element into another. However, not all types of carbon, for example, are the same. Different types have different numbers of neutrons (but the same number of protons) and are called isotopes. Astronomers can study stars by looking at the light that shines from them. From this light they can tell what elements are produced and this gives nuclear physicists information on which nuclear reactions could be important. We know that many of the elements heavier than iron are produced by the so-called s-process by adding neutrons to existing isotopes. The proposed research programme will use the beams available at the TRIUMF laboratory in Vancouver to study one reaction which influences how many neutrons are available for the s-process and therefore what the abundances of the heavy elements produced in the star are.