The production of the industrially significant radionuclide polonium-210 from the neutron irradiation of bismuth metal and the subsequent beta decay of bismuth-210 is highly inefficient due to the small neutron capture cross section of bismuth-209. In this paper, we report a previously undescribed self-sustaining nuclear chain reaction involving self-propagating neutron multiplication in bismuth salts that allow for rapid and cost-effective production of polonium-210. The reaction proceeds in a cycle of three alternating elementary steps – the capture of neutrons by bismuth-209 and the subsequent formation of polonium-210, the emission of high-energy alpha particles by polonium-210, and the production of more neutrons from (α, n) and (n,2n) reactions on light element and bismuth-209 nuclei respectively. Furthermore, the high hydrogen density of the compound also confers it intrinsic neutron moderation properties, increasing the neutron capture cross section of bismuth-209 at thermal neutron energies. The chain reaction was proven to have successfully occurred by irradiating a sample of the bismuth salt with a 80 μCi neutron source and monitoring the activity levels of the reaction. It was found that the activity of the reaction increased exponentially after an initial stable period following a derived formula for polonium production trends for the reaction, thus validating the occurrence of the reaction. Furthermore, alpha spectroscopy confirmed that polonium-210 had been produced by characterising the 5.30 MeV alpha emission peak of the reaction in addition to using beta spectroscopy to identify the parent nuclide bismuth-210, further proving that the reaction was successful. Hence, this paper reports the successful initiation and characterisation of a novel nuclear chain reaction, and its potential applications offered by a method of rapidly producing large quantities of polonium-210.

Abstract

The questions of reality have always followed mankind, at least, throughout the last two centuries. Does reality actually exist or is it just a simulation of a higher form of life? Are we alone in the universe? Is there any way to travel from one period of time to another? Does time have a certain direction? Could parallel worlds actually exist? This paper tries to answer these and more based on the thematic questions. I also analyze and reckon other paradoxes of the quantum world. My reflections and some sort of proof are mostly based on quantum physics and philosophical ways of thinking. From the very beginning, I would also like to emphasize the importance of the fact that a considerable part of the musings is only probabilistic, due to the current inability of mankind to prove such kinds of things.

The interest in using scalable data processing solutions based on Apache Hadoop ecosystem is constantly growing in the High Energy Physics (HEP) community. This drives the need for increased reliability and availability of the central Hadoop service and underlying infrastructure provided to the community by the CERN IT department. This paper reports on the overall status of the Hadoop platform and related Hadoop and Spark service at CERN, detailing recent enhancements and features introduced in many areas including the service configuration, availability, alerting, monitoring and data protection, in order to meet the new requirements posed by the users’ community