Speaker
Description
In the KArlsruhe TRItium Neutrino (KATRIN) experiment we perform a precision measurement of the tritium beta decay spectrum. Our goal is to determine the neutrino mass by investigating the spectrum shape near the endpoint region at around $18.6$ keV. Recently we have published a new direct upper limit on neutrino mass of $0.8$ eV/c${}^2$ (90% C.L.) which has been obtained with only 5% of the anticipated total measurement time. However, reaching the target sensitivity of $0.2$ eV/c${}^2$ at 90% C.L. not only requires the full measurement time, but also the detailed study of systematic measurement uncertainties. Several of them can be studied by measuring a shape distortion of the ${}^{\text{83m}}$Kr electron conversion lines which are commonly used for calibration purposes of different (astro-)particle physics experiments. This creates high demands on precise knowledge of the undistorted krypton spectrum.
In KATRIN we use the $32$ keV N-lines lying in the high energy region of the ${}^{\text{83m}}$Kr spectrum including the weaker N$_\text{1}$ line. In this talk I will present current results of a dedicated ${}^{\text{83m}}$Kr electron N-spectrum measurement with emphasis on N$_\text{1}$ line conducted at KATRIN.
