Impact of ADC non-linearities on the sensitivity to sterile keV neutrinos with a KATRIN-like experiment

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2016-12, Vol.848 (C)
• Main Authors: Dolde, Kai, Mertens, Susanne, Radford, David C., Bode, Tobias, Huber, Anton, Korzeczek, Marc, Lasserre, Thierry, Slezak, Martin
• Format: Article
• Language: English
• Subjects: ADC non-linearities; ATOMIC AND MOLECULAR PHYSICS; KATRIN; Sterile neutrinos; Tritium β-decay
• ISSN: 0168-9002; 1872-9576

Here, ADC non-linearities are a major systematic effect in the search for keV-scale sterile neutrinos with tritium β-decay experiments like KATRIN. They can significantly distort the spectral shape and thereby obscure the tiny kink-like signature of a sterile neutrino. In this work we demonstrate various mitigation techniques to reduce the impact of ADC non-linearities on the tritium β-decay spectrum to a level of < ppm. The best results are achieved with a multi-pixel (≥ 104 pixels) detector using full waveform digitization. In this case, active-to-sterile mixing angles of the order of sin2θ = 10–7 would be accessible from the viewpoint of ADC non-linearities. With purely peak-sensing ADCs a comparable sensitivity could be reached with highly linear ADCs, sufficient non-linearity corrections or by increasing the number of pixels to ≥ 105.