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Abstract

In particle physics, especially in neutrino physics, there is rising demand for safe
liquid scintillators in large detectors. Therefore, different scintillators, which are
characterised by a high flash point and low vapour pressure, were studied in context
of this work. The optical properties of different safe solvent were optimized
by the selection of different wavelength shifters and variation of their concentration.
In particular, the light yield, attenuation length and the capability of Pulse
Shape Discrimination (PSD) of different scintillator samples were determined. In
this context we found three promising scintillator samples based on DIN, LAB
and silicone oil. The DIN based scintillator has an outstanding light yield and
PSD, but a relative low attenuation length. The LAB based scintillator on the
other hand has a more than five times larger attenuation length than DIN, but a
lower light yield and PSD. The silicone oil based scintillator has a slightly worse
light yield and PSD than LAB, but is characterised by a very high flash point and
very low vapour pressure even compared to other safe scintillators. Moreover, it
is chemical inert, simple disposable and classified with no GHS pictogram.