Speaker
Mr
Bernhard Flierl
(LMU Munich)
Description
Position resolving detection of thermal neutrons combined with timing information and high flux capability are key features of detectors in spallation sources like the ESS. In order to reach the extremely low
spatial resolution of less than 200 µm for neutron tomography or radiography novel readout scheme based on the time-projection-chamber (TPC) concept is used in a gaseous electron multiplier (GEM) detector. Thermal neutrons are captured in a single 2 µm thick Boron-10 converter cathode and secondary Helium and Lithium ions are produced with a combined energy of 2.8 MeV. These ions have sufficient energy to form tracks of several mm length.
With a time resolving 2-dimensional readout of 400 µm pitch in both directions, based on APV25 chips, the ions are tracked and their respective origin in the cathode converter foil is reconstructed.
Using n Ar-CO2 93:7% gas mixture, a resolution of 100 µm has been observed with a triple GEM-detector setup at the Garching Neutron source (FRMII) for neutrons of 4.7 A.
Primary author
Mr
Bernhard Flierl
(LMU Munich)
Co-authors
Dr
Karl Zeitelhack
(Forschungsneutronenquelle Heinz-Meier-Leibnitz)
Prof.
Otmar Biebel
(LMU Munich)
Dr
Ralf Hertenberger
(LMU Munich)
