Neutron emission measurements, by means of He3 devices and bubble detectors, were performed during three different kinds of compression tests on brittle rocks: (i) under monotonic displacement control, (ii) under cyclic loading, and (iii) by ultrasonic vibration. The material used for the tests was Luserna stone, with different specimen sizes and shapes, and consequently with different brittleness numbers. Some studies had been already conducted on the different forms of energy emitted during the failure of brittle materials. They are based on the signals captured by acoustic emission measurement systems, or on the detection of electromagnetic charge. On the other hand, piezonuclear neutron emissions from very brittle rock specimens in compression have been discovered only very recently. In this paper, the authors analyse this phenomenon from an experimental point of view. Since the analyzed material contains iron, additional experiments have been performed on steel specimens subjected to tension and compression, observing, also in this case, neutron emissions well distinguishable from the background level. Our conjecture is that piezonuclear reactions involving fission of iron into aluminum, or into magnesium and silicon, should have occurred during compression damage and failure. This hypothesis is confirmed by the direct evidence of Energy Dispersive X-ray Spectroscopy (EDS) tests conducted on the specimens. It is also interesting to emphasize that the anomalous chemical balances of the major events that have affected the geomechanical and geochemical evolution of the Earth’s Crust should be considered as an indirect evidence of the piezonuclear fission reactions considered above.
Piezonuclear Fission Reactions from Earthquakes and Brittle Rocks Failure: Evidence of Neutron Emission and Non-Radioactive Product Elements / A. CARPINTERI; G. LACIDOGNA; A. MANUELLO; O. BORLA. - In: EXPERIMENTAL MECHANICS. - ISSN 0014-4851. - STAMPA. - 53:3(2013), pp. 345-365. [10.1007/s11340-012-9629-x]
|Titolo:||Piezonuclear Fission Reactions from Earthquakes and Brittle Rocks Failure: Evidence of Neutron Emission and Non-Radioactive Product Elements|
|Data di pubblicazione:||2013|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1007/s11340-012-9629-x|
|Appare nelle tipologie:||1.1 Articolo in rivista|