Cosmogenic radionuclides reveal an extreme solar particle storm near a solar minimum 9125 years BP

During solar storms, the Sun expels large amounts of energetic particles (SEP) that can react with the Earth’s atmospheric constituents and produce cosmogenic radionuclides such as 14C, 10Be and 36Cl. Here we present 10Be and 36Cl data measured in ice cores from Greenland and Antarctica. The data consistently show one of the largest 10Be and 36Cl production peaks detected so far, most likely produced by an extreme SEP event that hit Earth 9125 years BP (before present, i.e., before 1950 CE), i.e., 7176 BCE. Using the 36Cl/10Be ratio, we demonstrate that this event was characterized by a very hard energy spectrum and was possibly up to two orders of magnitude larger than any SEP event during the instrumental period. Furthermore, we provide 10Be-based evidence that, contrary to expectations, the SEP event occurred near a solar minimum.

IMAGE ANALYSIS OF PARTICLE FLOW IN CENTRIFUGAL SOLAR PARTICLE RECEIVER

Particle solar receivers promise economical and operational advantages compared to the molten salt based solar receivers. In this study, an experiment is designed to observe the particle flow characteristics in the Centrifugal Solar Particle Receiver. A set of experiments for various receiver rotation speeds and particle mass flow rates is conducted, and experimentally obtained raw results are post-processed by means of an Image Processing Routine based on 4BestEstimate algorithm[1]. The axial advance of the particles in one turn, the particle film thickness and the ratio of the stationary zone to the receiver circumference are measured in order to be later used in the validation study of the Discrete Element Method based numerical model.

Image Analysis of Particle Flow in Centrifugal Solar Particle Receiver

Particle solar receivers promise economical and operational advantages compared to the molten salt based solar receivers. In this study, an experiment is designed to observe the particle flow characteristics in the Centrifugal Solar Particle Receiver. A set of experiments for various receiver rotation speeds and particle mass flow rates is conducted, and experimentally obtained raw results are post-processed by means of an Image Processing Routine based on 4BestEstimate algorithm[1]. The axial advance of the particles in 1 turn, the particle film thickness and the ratio of the stationary zone to the receiver circumference are measured in order to be later used in the validation study of the Discrete Element Method based numerical model.