Piezonuclear Neutrons From Brittle Fracture: Early Results of Mechanical Compression Tests¹

Abstract

Neutron emission measurements by means of helium-3 neutron detectors were performed on solid test specimens during crushing failure. The materials used were marble and granite, selected in that they present a different behaviour in compression failure (i.e. a different brittleness index) and a different iron content. All the test specimens were of the same size and shape. Neutron emissions from the granite test specimens were found to be of about one order of magnitude larger than the natural background level at the time of failure. These neutron emissions were caused by piezonuclear reactions that occurred in the granite, but did not occur in the marble. This is because of the fact that in granite the release rate of accumulated elastic energy DE exceeds the power threshold for the generation of piezonuclear reactions, W strong = 7.69 · 10 11 W. Moreover, granite contains iron, which has been ascertained to be the most favourable element for the production of piezonuclear reactions when the nuclear interaction energy threshold, E 0,strong = 5.888 · 10 )8 J, is exceeded in deformed space-time conditions.

Piezonuclear Fission Reactions in Rocks: Evidences from Microchemical Analysis, Neutron Emission, and Geological Transformation

“…Piezonuclear fission reactions consist of a new nuclear phenomenon, produced by physical causes such as pressure, fracture or cavitation, and from which neutrons can be produced without gamma emission. This physical phenomenon could be the signature of a new physics of nuclear interactions, as it is theoretically and experimentally discussed in the literature (Cardone and Mignani 2004Cardone et al 2009). …”

“…They are based on the signals captured by the acoustic emission measurement systems, or on the detection of the electromagnetic charge. On the other hand, only very recently piezonuclear neutron emissions from very brittle rock specimens in compression have been discovered (Carpinteri et al 2009(Carpinteri et al , 2010aCardone et al 2009). Piezonuclear fission reactions consist of a new nuclear phenomenon, produced by physical causes such as pressure, fracture or cavitation, and from which neutrons can be produced without gamma emission.…”

“…In the experiments on liquid solutions (Cardone and Mignani 2007;Cardone et al 2009), aluminum atoms appeared at the end in a final quantity as large as about seven times the small initial quantity (Cardone et al 2009). By analogy with the case of piezonuclear reactions in liquids, a factor to be taken into account is the composition of the materials in which piezonuclear reactions may be produced.…”

“…We carried out three different kinds of compression tests: (1) under monotonic displacement control, (2) under cyclic loading, and (3) by ultrasonic solicitations. Similar to the preliminary piezonuclear experiments presented in (Carpinteri et al 2009(Carpinteri et al , 2010aCardone et al 2009), the material used for the tests is non-radioactive Luserna Stone, a metamorphic rock deriving from a granitoid protolith. In these new tests, cylindrical specimens with different size and slenderness are used to assess neutron emissions related to specimens with very brittle behavior.…”

“…Piezonuclear reactions with neutron emissions were obtained for the first time in liquids containing iron chloride or iron nitrate subjected to ultrasounds and cavitation (Cardone and Mignani 2007;Cardone et al 2009). In the experiments on liquid solutions (Cardone and Mignani 2007;Cardone et al 2009), aluminum atoms appeared at the end in a final quantity as large as about seven times the small initial quantity (Cardone et al 2009).…”