Some nuclear fusion reactions inside stars occur more slowly than we thought and, as a consequence, stars themselves, as well as galaxies and the entire universe are a bit older than expected. This is what comes out from the last results of Luna experiment (Laboratory for Underground Nuclear astrophysics), settled by National Laboratories of Gran Sasso and realized in cooperation by Infn and Ruhr University in Bochum (Germany). The study, that will be published on the review Physics Letters B next June 17, has been published today on the website of the review. A second article has been accepted by the review Astronomy and Astrophysics.
Luna’s aim is the production of some reactions that occur inside stars, in particular in the Sun, and the measure of their velocity. In Luna, protons (which means hydrogen nuclei) are made collide against nitrogen nuclei: a reaction that leads to the formation of an oxygen nucleus with the contemporary emission of energy. “The great part of the energy emitted by our star derives from fusion reactions of four hydrogen nuclei that lead directly to the formation of a helium nucleus. But there is another process in consequence of that helium nuclei are produced and this process passes through the so-called carbon-nitrogen-oxygen cycle. Cycle velocity is determined by the slowest of the reactions that form it, the one that leads to an oxygen nucleus as a result of the fusion between an azote nucleus and a proton. That is to say the reaction studied by Luna”, explains Carlo Broggini, Luna coordinator.
Producing fusion between the nitrogen nucleus and a proton is not difficult itself, but a difficulty lies in obtaining it at the same energy it occurs in stars: a relatively low energy, thanks to which the phenomena is quite slow, corresponding to a very few reactions a day (a lucky case for our planet, because if these phenomena occurred rapidly, the Sun would have burned up its ‘fuel’ in a few time and this would have made life –as we know it -impossible). “In an ordinary laboratory settled on surface, the effects of the reaction studied by Luna would be totally hidden by similar, but much more abundant effects due to reactions caused by the cosmic rays rain that crashes into our planet without interruption. The Gran Sasso Laboratories are on the contrary located under 1.400 meters of rocks, which constitute an impenetrable barrier for almost all the particles coming from Space. Thanks to these particular conditions we could carry out our experiment”, says Carlo Broggini.
Carlo Broggini | alfa
Thin films from Braunschweig on the way to Mercury
19.10.2018 | Fraunhofer-Institut für Schicht- und Oberflächentechnik IST
Extremely close look at electron advances frontiers in particle physics
19.10.2018 | National Science Foundation
Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz (Germany) together with scientists from Dresden, Leipzig, Sofia (Bulgaria) and Madrid (Spain) have now developed and characterized a novel, metal-organic material which displays electrical properties mimicking those of highly crystalline silicon. The material which can easily be fabricated at room temperature could serve as a replacement for expensive conventional inorganic materials used in optoelectronics.
Silicon, a so called semiconductor, is currently widely employed for the development of components such as solar cells, LEDs or computer chips. High purity...
Augsburg chemists present a new technology for compressing, storing and transporting highly volatile gases in porous frameworks/New prospects for gas-powered vehicles
Storage of highly volatile gases has always been a major technological challenge, not least for use in the automotive sector, for, for example, methane or...
When we put water in a freezer, water molecules crystallize and form ice. This change from one phase of matter to another is called a phase transition. While this transition, and countless others that occur in nature, typically takes place at the same fixed conditions, such as the freezing point, one can ask how it can be influenced in a controlled way.
We are all familiar with such control of the freezing transition, as it is an essential ingredient in the art of making a sorbet or a slushy. To make a cold...
Thin organic layers provide machines and equipment with new functions. They enable, for example, tiny energy recuperators. In future, these will be installed...
Das Zusammenspiel aus Struktur und Dynamik bestimmt die Funktion von Proteinen, den molekularen Werkzeugen der Zelle. Durch Fortschritte in der...
17.10.2018 | Event News
16.10.2018 | Event News
02.10.2018 | Event News
19.10.2018 | Life Sciences
19.10.2018 | Physics and Astronomy
19.10.2018 | Trade Fair News