Bremen 2017 – wissenschaftliches Programm

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UP: Fachverband Umweltphysik

UP 4: Boden- und Agrarphysik

UP 4.3: Vortrag

Dienstag, 14. März 2017, 16:15–16:30, GW2 B3009

Detection systems for neutron-based soil moisture measurements — •Jannis Weimar¹, Markus Köhli¹, Martin Schrön², and Ulrich Schmidt¹ — ¹Physikalisches Institut, Heidelberg, Deutschland — ²Helmholtz-Zentrum für Umweltforschung, Leipzig, Deutschland

During the past years an interdisciplinary community of scientists has established a non-invasive soil moisture measurement technique using secondary cosmic ray neutrons. The method is based on the characteristic of hydrogen to effectively moderate neutrons. Consequently the amount of reflected fast neutrons strongly depends on the water content of the soil. The method has proven to be capable of closing the gap in spatial resolution between satellite and point-like measurements by providing a footprint of several hectares, which makes it a promising candidate for multiple applications in environmental science.

Neutron detection systems involve materials that convert weakly interacting neutrons into ionizing particles. For a long time such have relied on Helium-3 as an efficient agent with a high absorption cross-section. Its current scarcity demands for technological solutions with other converters. In Heidelberg a boron-10-lined detector has been designed offering lower costs at good detection rates. It is also the onset for a mobile detection system which allows for measurements on larger scales at otherwise inaccessible terrain. The talk will cover preliminary measurement results and comparisons to recent Monte-Carlo simulations.