arXiv subjects

Florian Priester

Publications and source records attributed to Florian Priester.

7 recordsLinked to original sources

arXiv2026

Gaseous Tritium Activity Monitoring with Scintillators (GaTAMoS)

We present a novel device for the inline activity monitoring of gaseous tritium, named Gaseous Tritium Activity Monitoring with Scintillators (GaTAMOS). Unlike established methods that often rely on liquid scintillation or plastic scintillators with limited chemical resistance, this system utilises a chemically inert, inorganic Terbium-activated Gadolinium Oxysulfide (Gd2O2S:Tb) ceramic. A specialised soldering technique was developed to join the ceramic scintillator to a stainless-steel flange, achieving a vacuum-tight seal fully compatible with high-purity tritium applications. The device was characterised using pure tritium gas, demonstrating a linear response and high sensitivity across a dynamic range from < 1 kBq to >10 GBq. A key advantage of the ceramic material over organic alternatives is its high tolerance to aggressive cleaning agents. We demonstrate that the inevitable tritium memory effect can be significantly mitigated by flushing the cell with ethanol, removing >95% of residual contamination within minutes. The proposed system offers a compact, robust, and cost-effective alternative to ionisation chambers or BIXS systems for process monitoring in tritium handling facilities.

physics.ins-det↗

arXiv2025

Sterile-neutrino search based on 259 days of KATRIN data

Neutrinos are the most abundant fundamental matter particles in the Universe and play a crucial role in particle physics and cosmology. Neutrino oscillation, discovered about 25 years ago, reveals that the three known species mix with each other. Anomalous results from reactor and radioactive-source experiments suggest a possible fourth neutrino state, the sterile neutrino, which does not interact via the weak force. The KATRIN experiment, primarily designed to measure the neutrino mass via tritium $\beta$-decay, also searches for sterile neutrinos suggested by these anomalies. A sterile-neutrino signal would appear as a distortion in the $\beta$-decay energy spectrum, characterized by a discontinuity in curvature (kink) related to the sterile-neutrino mass. This signature, which depends only on the shape of the spectrum rather than its absolute normalization, offers a robust, complementary approach to reactor experiments. KATRIN examined the energy spectrum of 36 million tritium $\beta$-decay electrons recorded in 259 measurement days within the last 40 electronvolt below the endpoint. The results exclude a substantial part of the parameter space suggested by the gallium anomaly and challenge the Neutrino-4 claim. Together with other neutrino-disappearance experiments, KATRIN probes sterile-to-active mass splittings from a fraction of an electron-volt squared to several hundred electron-volts squared, excluding light sterile neutrinos with mixing angles above a few percent.

hep-ex↗

arXiv2022

ViMA -- the spinning rotor gauge to measure the viscosity of tritium between 77 and 300 K

Experimental values for the viscosity of the radioactive hydrogen isotope tritium (T$_2$) are currently unavailable in literature. The value of this material property over a wide temperature range is of interest for applications in the field of fusion, neutrino physics, as well as to test ab initio calculations. As a radioactive gas, tritium requires careful experiment design to ensure safe and environmental contamination free measurements. In this contribution, we present a spinning rotor gauge based, tritium compatible design of a gas viscosity measurement apparatus (ViMA) capable of covering the temperature range from 80 K to 300 K.

physics.ins-det↗

arXiv2022

Operation Modes of the KATRIN Experiment Tritium Loop System using $^{83\mathrm{m}}$Kr

The KArlsruhe TRItium Neutrino (KATRIN) experiment aims to search for the effective electron antineutrino mass with a sensitivity of 0.2 eV (90 % C.L.). In order to achieve this goal, KATRIN measurement phases focusing on the neutrino mass search are alternated with phases of investigations of systematic effects. During these phases, metastable $^{83\mathrm{m}}$Kr is used as a calibration source. The monoenergetic conversion electrons emitted accompanying the decay of $^{83\mathrm{m}}$Kr allow a direct access to the starting conditions of $β$-electrons produced inside the windowless gaseous tritium source (WGTS) of KATRIN. To make use of $^{83\mathrm{m}}$Kr in the WGTS, the Tritium Loop System, which provides a stable flow of tritium to the WGTS, needs to be operated in special modes. This paper focuses on the technical implementation of these modes and their performance with regard to the achievable $^{83\mathrm{m}}$Kr-rates, gas densities, and gas compositions inside the WGTS.

physics.ins-det↗

arXiv2022

Viscosity measurements of gaseous H2 between 200 K to 300 K with a spinning rotor gauge

Experimental values for the viscosity of the radioactive hydrogen isotopologue tritium are still unknown in literature. Existing values from ab initio calculations disregard quantum mechanic effects and are therefore only good approximations for room temperature and above. To fill in these missing experimental values, a measurement setup has been designed, to measure the viscosity of gaseous hydrogen and its isotopologues (H$_2$, HD, HT, D$_2$, DT, T$_2$) at cryogenic temperatures. In this paper, the first results with this Cryogenic Viscosity Measurement Apparatus (Cryo-ViMA) of the viscosity of gaseous hydrogen between 200 K to 300 K are presented.

physics.ins-det↗

arXiv2020

Neutral tritium gas reduction in the KATRIN differential pumping sections

The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to measure the effective electron anti-neutrino mass with an unprecedented sensitivity of $0.2\,\mathrm{eV}/\mathrm{c}^2$, using $β$-electrons from tritium decay. The electrons are guided magnetically by a system of superconducting magnets through a vacuum beamline from the windowless gaseous tritium source through differential and cryogenic pumping sections to a high resolution spectrometer and a segmented silicon pin detector. At the same time tritium gas has to be prevented from entering the spectrometer. Therefore, the pumping sections have to reduce the tritium flow by more than 14 orders of magnitude. This paper describes the measurement of the reduction factor of the differential pumping section performed with high purity tritium gas during the first measurement campaigns of the KATRIN experiment. The reduction factor results are compared with previously performed simulations, as well as the stringent requirements of the KATRIN experiment.

physics.ins-det↗

arXiv2012

Monitoring of tritium purity during long-term circulation in the KATRIN test experiment LOOPINO using laser Raman spectroscopy

The gas circulation loop LOOPINO has been set up and commissioned at Tritium Laboratory Karlsruhe (TLK) to perform Raman measurements of circulating tritium mixtures under conditions similar to the inner loop system of the neutrino-mass experiment KATRIN, which is currently under construction. A custom-made interface is used to connect the tritium containing measurement cell, located inside a glove box, with the Raman setup standing on the outside. A tritium sample (purity > 95%, 20 kPa total pressure) was circulated in LOOPINO for more than three weeks with a total throughput of 770 g of tritium. Compositional changes in the sample and the formation of tritiated and deuterated methanes CT_(4-n)X_n (X=H,D; n=0,1) were observed. Both effects are caused by hydrogen isotope exchange reactions and gas-wall interactions, due to tritium β decay. A precision of 0.1% was achieved for the monitoring of the T_2 Q_1-branch, which fulfills the requirements for the KATRIN experiment and demonstrates the feasibility of high-precision Raman measurements with tritium inside a glove box.

physics.ins-det↗