Scintillation crystals convert the energy of ionizing radiation (α, β, or γ radiation) into a flash of light that is subsequently detected by a photon detector like a photomultiplier tube or photodiode. In the section LM we develop better scintillation crystal for applications in medical diagnostics, home land security, and industrial applications. We pioneered the field of halide (chloride, bromide, iodide) based inorganic crystals and discovered around 2000 LaCl3:Ce3+ and LaBr3:Ce3+ that are commercialized under trade names BrilLanCeTM350 and BrilLanCeTM380. In 2013 we developed an improved version that still holds the world record low energy resolution of 2.0% (FWHM) for detection of 662 keV γ-photons.
The new scintillator was further developed by the company Saint-Gobain and is now commercial available under trade name BrilLanCeTM390 ( https://www.crystals.saint-gobain.com/products/brillance-labr3-lanthanum-bromidehttps://www.crystals.saint-gobain.com/products/brillance-labr3-lanthanum-bromide )
In collaboration with the European Space Agency (SA) and Saint-Gobain the section LM developed and tested LaBr3:Ce scintillators for the Mercury Gamma-Ray and neutron Spectrometer that will fly to the planet Mercury in the Bepi Colombo mission. The satellite will be launched in September 2019.
Scintillation pulse height spectrum of a 137Cs gamma-source detected with a ~10 mm3 sized LaBr3:Ce3+;Sr2+ crystal (Alekhin et al. Appl. Phys. Lett. 102 (2013) 161915).
The Bepi Colombo satellite in the testing hall at ESA, Noordwijk, The Netherlands with in the middle of the stack the MPO (Mercury Polar Orbiter) that contains the Mercury Gamma-Ray and Neutron Spectrometer (MGNS) with the bromide scintillator crystal. (https://www.cosmos.esa.int/web/bepicolombo/mgns)
Projects in scintillation research
Development of new scintillators
In collaboration with the University of Bern and the company Saint-Gobain we aim to develop new materials in the shape of single crystals for detection of ionizing radiation. Due the increasing demand in very fast scintillators we have an applied and fundamental research activity to study the very early stages (10-100 picoseconds) of the scintillation process.
Precise determination of the β-continuum
In the decay of radioactive isotopes like 138La, 40K, 176Lu a β-particle and a neutrino is emitted from the nucleus. By accurate measuring the scintillation pulses from those radioactive isotopes present as unintentional impurities in scintillation crystals, in collaboration with Gonitec BV the aim is to precisely measure the distribution in β-particle energy (the shape of the β-continuum). Accurate knowledge is of importance for fundamental understanding of the nuclear decay process and how, in the case of 40K, heat is generated in the interior of our planet.