Tritium permeation from Breeding Blanket (BB) towards Primary Heat Transfer System (PHTS) is an issue for operation of DEMO machine since, once permeated into PHTS, tritium can migrate to working areas and environment via permeation and leaks. In order to control radioactive release two strategies was individuated to keep tritium concentration within primary coolant below fixed limits: the use...
To measure the absolute neutrino mass by Cyclotron Radiation Emission Spectroscopy (CRES) following beta-decay of atomic tritium, it is essential to generate dense atomic beams, implement methods for state-selection and magnetic confinement of ground-state atoms, and perform high-precision in-situ magnetometry and electrometry. These represent some of the aims of the UK Quantum Technologies...
Metallic Magnetic Calorimeters (MMCs) are low temperature single particle detectors, whose working principle is based on quantum technology. Due to their excellent energy resolution, near linear detector response, fast signal rise time and close to 100\% quantum efficiency, MMCs outperform conventional detectors by several orders of magnitude, making them interesting for a wide range of...
KATRIN has recently reported a direct sub-eV upper bound on the neutrino mass from tritium beta-decay spectrum measurements. Along with the neutrino mass search, KATRIN has published recent results on searching for a fourth neutrino with a mass in the eV-range using the precision beta-decay spectra.
The fourth neutrino mass-eigenstate introduces an additional branch into the tritium...
The Karlsruhe Tritium Neutrino (KATRIN) experiment currently provides the world-leading upper limit on the effective neutrino mass, $m_{\nu}<0.8\,\text{eV}$. Since KATRIN performs a direct, model-independent measurement of the neutrino mass, the project is of high interest for the neutrino and particle physics community.
At KATRIN, anti-electron neutrinos are produced by tritium beta decays,...
The KATRIN collaboration aims to determine the neutrino mass with a sensitivity of 0.2 eV/c² (90% CL). This will be achieved by probing the endpoint region of the β-electron spectrum of gaseous tritium with an electrostatic spectrometer. A gold-coated stainless steel disk defines the reference potential for the high precision neutrino mass measurement and it terminates the β-electron flux as...
A major focus of the research at Tritium Laboratory Karlsruhe (TLK) is to develop key technologies needed both for fusion and for the operation of the KATRIN experiment. One important consideration towards maintenance and decommissioning of tritium experiments is the development of suitable decontamination procedures. These could also be applied to reduce tritium memory effects, e.g. of...
The KATRIN experiment at the Karlsruhe Institute of Technology (KIT) aims to determine the effective neutrino mass using the kinematics of electrons from the tritium 𝛽-decay. The integral energy spectrum of the electrons is measured by a electro-static high-pass filter, using the MAC-E filter principle (Magnetic Adiabatic Collimation and Energy filter). Only electrons with energies above the...
KATRIN is probing the effective electron anti-neutrino mass by a precision measurement of the tritium beta-decay spectrum near the kinematic endpoint. Based on the first two measurement campaigns a world-leading upper limit of 0.8 eV (90% CL) was placed. New operational conditions for an improved signal-to-background ratio, the steady reduction of systematic uncertainties and a substantial...
The KATRIN experiment aims at the direct measurement of the neutrino mass scale via precision endpoint spectroscopy of β-electrons produced in the decay of molecular tritium with a target sensitivity of 0.2 eV/c² (90% C.L.).
An important systematic effect entering the analysis are energy-losses of β-electrons due to scattering off tritium molecules inside the source. The energy-loss function...
Experimental values for the viscosity of tritium are still unknown in literature. Values to be found are ab initio calculated values, which are only valid for 300 K and higher. For lower temperatures, only values extrapolated from hydrogen and deuterium exist, with an uncertainty of 5-10 %. The viscosity of tritium is an important parameter, needed for gas dynamics simulations, for example in...
The UNITY (Unique Integrated Testing Facility) is currently under construction in Japan. The facility will be capable of performing integrated testing of components necessary for the primary and secondary thermal cycles used in power generation and fuel cycle of early fusion power plants. The thermal section of the facility will have heating capacity for blanket modules up to 0.1 m² of...
Not only the isotopologues of hydrogen can be separated by cryogenic distillation but also the nuclear spin isomers of H2, D2 and T2 (ortho, para). One application of the ortho para distillation is the measurement of the separation performance of a distillation column quantified by the height equivalent of theoretical plates (HETP). Compared to isotope mixtures the relative volatility of the...
In recent years, there has been a growing interest in conducting in-situ Raman measurements on tritium-loaded graphene or graphene-like samples due to proposals in neutrino physics programs like KATRIN and PTOLEMY. A confocal Raman microscope (CRM), which can used for spatio-chemical analysis of these samples, could become radioactive contaminated due to post-loading desorption of tritiated...
The Quantum Technologies for Neutrino Mass (QTNM) project aims to utilise Cyclotron Radiation Emission Spectroscopy, along with unique quantum breakthroughs, to make measurements of the effective neutrino mass at the sub-eV level. In order to design this experiment, bespoke simulation tools have been developed which allow various options to be evaluated. These tools allow us to effectively...
The current best limit on the anti-electron neutrino mass of $m_{\nu}<0.8\,\mathrm{eV \, c^{-2}\ (90\,\% \ CL)}$ was published by the KATRIN collaboration in 2021.
For this, spectroscopy of electrons from the decay of molecular tritium is used.
Due to molecular excitation states however, the sensitivity of experiments using molecular tritium is limited to $\approx 0.1\,\mathrm{eV \,...
Tests of molecular quantum electrodynamics in the hydrogen benchmark species have predominantly targeted stable isotopes such as H2, HD, and D2. Accurate dissociation energy measurements [1] have shown remarkable agreement with theoretical predictions [2,3]. While various cavity-enhanced techniques have been employed to measure vibrational splittings, particularly in HD [4,5], these endeavors...
Abstract — An unavoidable category of molecular species in large-scale tritium applications, such as nuclear fusion, are tritium-substituted hydrocarbons, which form by radiochemical reactions in the 10 presence of (circulating) tritium and carbon (mainly from the steel of vessels and tubing). Tritium substituted methane species, CQ4 (with Q = H,D,T), are often the precursor for higher-order...
Since 30 years tritium experiments and facilities are being set up at Tritium Laboratory Karlsruhe (TLK). This is done in a framework of technical and administrative rules to ensure that during all operation, the requirements set by the TLK tritium licence is upheld and a safe and reliable operation is guaranteed, while the environment in which science is performed has a maximum of...
Sterile neutrinos are a possible extension of the Standard Model of particle physics. If their mass is in the keV range, they are a suitable dark matter candidate. One way to search for sterile neutrinos in a laboratory-based experiment is via tritium beta decay. A sterile neutrino with a mass up to 18.6 keV would manifest itself in the decay spectrum as a kink-like distortion.
The Karlsruhe...
The Karlsruhe Tritium Neutrino experiment (KATRIN) measures the tritium β-spectrum close to the maximum decay energy to achieve the value of the electron-antineutrino mass with a sensitivity of 0.2 eV/c2 (90% C.L.). Since only a small fraction of the decay electrons carries nearly all the energy, a high luminous tritium source, with its supporting infrastructure facilities, is necessary.
Since...
An overview of the UKAEA Tritium Advanced Technology (H3AT) facility whose assembly will soon take place at UKAEA Culham after the successful completion of the detail design.
An overview of the tritium research strategy in the UKAEA Tritium Advanced Technology (H3AT) division. Based on tritium Quantification, Inventory minimisation and Containment, a four-year roadmap is presented.
The radioactive hydrogen isotope tritium is becoming increasingly important in research and industry. Since tritium has a very low availability, a closed tritium cycle is essential for applications on a technical scale, e.g. electricity generation from nuclear fusion. The physical properties of tritium present a particular challenge for safe handling. These include its (i) good permeability...
In tritium-bearing facilities such as fusion power plants, sorption processes form the basis for an accumulation of tritium at and behind contact surfaces. These processes, collectively called tritium memory effect, influence the accuracy of activity-based measurement methods such as BIXS or ionization counters. To quantify the properties of the tritium memory effect for different materials,...
