arXiv subjects

Dominic Batzler

Publications and source records attributed to Dominic Batzler.

4 recordsLinked to original sources

arXiv2025

Tritium accumulation and ozone decontamination of tungsten and beryllium

Tritium adsorption on surfaces creates a variety of issues, ranging from the fields of fusion applications to small and large-scale laboratory experiments using tritium. The extent to which tritium accumulates on surfaces is generally material-dependent and must be determined through experiments. Additionally, this surface contamination necessitates the implementation of appropriate decontamination procedures, preferably in-situ. A suitable method could be exposure to ozone during UV irradiation. However, it is currently not known if both components are necessary for the decontamination. At Tritium Laboratory Karlsruhe, both questions on contamination and decontamination can be addressed using a single experimental setup. With this, it is possible to expose solid samples to gaseous tritium to measure the temporal activity evolution. Furthermore, the system can be filled with dry air, and dry air containing ozone to explore their decontamination effect. Both measurement modes were applied to beryllium and tungsten samples, which were chosen for their relevance in fusion. The beryllium surface was observed to accumulate tritium more than four times faster than tungsten when exposed to gaseous tritium. Concerning the decontamination, without simultaneous UV irradiation, exposure to ozone did not have any distinct effect on the surface activity compared to simply using dry air. This leads to the conclusion that UV illumination of the surfaces is required to achieve a significant decontamination factor.

cond-mat.mtrl-sci↗

arXiv2025

First results of the Tritium Absorption InfraRed Spectroscopy (T2ApIR) experiment

The literature on experimentally verified material properties of tritium is sparse but information about this is crucial in fusion for pellet production (Magnetic Confined Fusion), target fueling (Inertial Confined Fusion), cryogenic distillation, as well as in astroparticle physics for neutrino experiments, and search for rare physics. To improve on this, the T$_2$ApIR experiment has been designed and built at the Tritium Laboratory Karlsruhe (TLK), and is in its scientific commissioning phase. The main focus of this experiment is to enable the investigation of the properties of all six hydrogen isotopologues and their mixtures in the gaseous, liquid, and solid phase, as well as the dynamics of their phase changes. In addition, mixtures with noble gases such as xenon and neon can be investigated. This is achieved using a cryogenic setup capable of reaching less than 10 in a measurement cell that allows optical access for infrared absorption spectroscopy, Raman spectroscopy and a polariscope setup, as well as temperature and pressure measurement.

physics.ins-det↗

arXiv2025

Commissioning of an experiment for thermodynamic and spectroscopic studies of hydrogen isotopologues at cryogenic conditions

To study thermodynamic properties and dynamic phase space behavior of hydrogen isotopologues (Q$_2$) at cryogenic temperatures and at high density, the Tritium Absorption InfraRed Spectroscopy 2 (T$_2$ApIR) experiment has been set up and commissioned at Tritium Laboratory Karlsruhe (TLK). In the frame of the experiment, Q$_2$ behavior in different phases, ortho/para states, temperatures (10 K - 300 K) and pressures (up to 2.5 bar a) will be investigated with optical methods, infrared and Raman spectroscopy. The facility consists of a fully tritium compatible cryostat, which includes an optical cell, ortho/para converter and windows for optical and spectroscopic studies. The cryostat can be cooled below the H$_2$ triple point by a two-stage cryocooler and contains openings in the cryogenic shielding for the optical access. The challenge of combining these scientific requirements in a design with high amounts of tritium (14 g), in a limited space, all while maintaining the TLK safety philosophy was solved by the presented design. The experiment is ready to be fully integrated into the TLK closed loop tritium infrastructure. This contribution reports a comprehensive overview of the commissioning phase of the experimental facility and the results of the first commissioning experiments, including cryogenic performance tests, commissioning experiments with non-radioactive gases, and tests of the analytical instruments.

cond-mat.stat-mech↗

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↗