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We cordially invite you to the celebration of 30th anniversary of TLK on May 23rd, 2023 at KIT campus north. The day starts with a ceremonial act at the FTU with highlights from the last 30 years, current challenges and our view of the future. In the afternoon, we show you, what has been achieved in guided lab tours. The day ends with a barbecue at the TLK where you can meet former, current and future colleagues, partners and collaborators.
Furthermore, on May 24th & 25th there will be a symposium on tritium science and technology. More information can be found on this indico page.
As we prepare to make the final arrangements, please help us by registering until May 1st, 2023 via this indico page.
The event on the 23rd May is free of charge for invited guests. For the symposium on the 24th and 25th May, the conference fee of 100 € covers meals, coffee breaks, a conference dinner and bus transfers between Karlsruhe inner city and the KIT campus north.
We are looking forward to celebrate our anniversary with you.
Dr. Beate Bornschein, on behalf of the TLK
We thank our sponsors for their generous support of our event!
For 75 years the shape of the beta spectrum of tritium has been our clearest window on the most mysterious property of the neutrinos, their mass. The discovery of neutrino oscillations gave us proof that neutrinos have mass, which is a direct contradiction of the minimal standard model of particle physics. But how much mass? Oscillations cannot give a number for the mass, other than that the average of the three masses must be at least 0.02 eV. The mass is needed to build the new standard model, and to help pin down such things as the equation of state of dark energy and the evolution of structure in cosmology. KATRIN, the first new laboratory experiment on the beta spectrum of tritium in more than 20 years, has now shown the mass to be no greater than 0.8 eV. KATRIN continues toward its sensitivity goal of 0.2 eV. If the mass is not in this range, a very different approach called “Project 8” has passed proof-of-concept tests with a scheme that might have even greater sensitivity.
Highest precision electron spectroscopy is required to determine the neutrino mass from tritium beta-decay. In molecular tritium, initial and final state excitations limit the achievable resolution on the neutrino mass to 100meV. Trapping tritium atoms magnetically at high purity will avoid this systematic effect and allow to surpass the sensitivity limit. Towards this goal, Project 8 will use CRES technology, which is compatible with such a source concept.
However, providing such an atomic source at the number density and size required to achieve the required event statistics constitutes a major challenge. In this talk, I will present a conceptual design towards producing, cooling and trapping an atomic tritium flux meeting our requirements.
The objective of the KArlsruhe TRItium Neutrino (KATRIN) experiment is the direct measurement of the effective mass of the electron antineutrino with an expected sensitivity of 0.2 eV/c² (90% CL) on the neutrino mass. As β-particle source KATRIN uses molecular tritium which decays in a "Windowless Gaseous Tritium Source” (WGTS). This kind of source consists of a gas dynamic system with a source tube of 90 mm in diameter and 10 m in length. The source tube is placed in a magnetic field of approx. 3 T and is pumped with differential pumping stages at both ends. In total, 26 turbomolecular pumps (TMP) are continuously operated within the KATRIN tritium handling system (loop system). After pumping down by the TMP’s and compressing to approx. 250 hPa by the transfer pumps, the tritium is purified with a palladium membrane filter and re-injected into the middle of the source tube (“closed loop operation”).
This talk will give an overview over the KATRIN tritium system, its commissioning and the measurement phases so far culminating in a total throughput of 22 kg over the WGTS.
Quantum Technologies for Neutrino Mass (QTNM) is a project recently funded in the UK by the Quantum Technologies for Fundamental Physics programme. Its goal is to harness recent breakthroughs in quantum sensors to assess the feasibility of a positive neutrino mass measurement with a sensitivity in the 0.01 - 0.1 eV range. It will use the Cyclotron Radiation Emission Spectroscopy (CRES) technique to measure the energy of electrons emitted in the beta-decay of atomic tritium.
To accomplish this goal QTNM is developing a number of quantum technologies such as quantum noise limited microwave amplifiers and Rydberg atoms magnetometry.
I will review the status of the QTNM project, the technological developments pursued by the collaboration, and will give an outlook into the project’s future.
The Ptolemy experiment plans to observe the cosmic neutrino background through neutrino capture on a tritium target. It is currently in the R&D phase. We present an overview of the design and the current state of the experiment and more recent results on the tritium target.
KATRIN, the KArlsruhe TRItium Neutrino experiment, is leading the charge in measuring the mass of electron neutrinos with an unprecedented sensitivity through the beta-decay of tritium. However, it is ultimately limited by systematic uncertainties like the molecular final state distribution. New technologies must be developed to surpass the experiment's current sensitivity limits. One promising but challenging technology is an atomic tritium source for KATRIN. In this presentation, we outline our strategy towards achieving this goal, including new test experiments developed at the Tritium Laboratory Karlsruhe (TLK) that pave the way towards an atomic tritium source. We discuss the development of a high-luminosity atomic tritium source, as well as crucial aspects such as beam cooling, beam shaping, and the use of analytical tools for beam characterization.
Atomic tritium promises to circumvent the major systematic limitation on direct neutrino mass experiments, enabling Project 8 to reach a sensitivity of 40 meV. Building such an apparatus requires splitting copious quantities of tritium into atoms, and no existing atom source that is compatible with tritium can reach our required flux.
In Mainz, we have built a high-flow hydrogen/deuterium test facility and measured the output of a commercial tungsten-capillary atom source to a flow 20 times larger than previously published. Combined with supporting efforts across the Project 8 collaboration, we have developed new experimental methods to study intense atom sources. Our latest test stand now permits stable, long-duration experiments with outstanding signal to noise. I will recount the progression of the test stand, discuss some of the methods we have designed, and show recent results.
We are using these results to map out previously unknown shortcomings of the existing atom-source theory at high flow, and to guide the design of a new generation of custom atom sources to achieve high efficiency, high atom flux, and reliable operation with tritium. Such a source will support the Project 8 Atomic Tritium Demonstrator, including its full-flux cold atom beamline and cubic-meter atom trap.
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 of anti-permeation barriers and/or the adoption of the Coolant Purification System (CPS).
Nowadays, two BB concepts are under investigation for DEMO, namely the Helium-Cooled Pebble Bed (HCPB) and Water-Cooled Lithium Lead (WCLL). The first one relies on helium as heat transport media whereas the latter involves water as primary coolant. Depending on the coolant medium, the proper technology must be selected to fulfill the CPS objective. For the HCPB case, the reference configuration relies on copper oxide (CuO) beds, to oxidize all the hydrogen isotopes present in the helium coolant, and Zeolite Molecular Sieve (ZMS) beds for the adsorption of tritiated water formed in the CuO beds. For the WCLL BB concept, Water Distillation (WD) is the most promising technology, due to its simplicity and intrinsic safety.
The present work deals with the presentation of the ongoing design and optimization activity for both the CPS technologies. Regarding the helium CPS, emphasis is posed on the experimental activity programmed for the near future, whereas for the water CPS the main assumption and an optimization procedure to reduce energy consumption are presented.
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 for Neutrino Mass (QTNM) project. Here we report advances in each of these areas in preliminary studies with atomic hydrogen. The techniques used can be transferred to experiments with tritium.
We present the operation and initial characterisation of a pulsed supersonic beam of atomic hydrogen. This is based on a DC discharge of H2. Detection of the ground-state atoms in this beam is implemented by resonance-enhanced multi-photon ionisation via the 2S intermediate state. The resulting H+ ions are collected at a microchannel plate detector.
In parallel with this, we have designed and simulated the operation of a magnetic state selector for the ground state atoms in this beam. The construction of this is underway and its design and operation will be presented. After state-selection, we plan to inject the atoms into a magnetic storage ring for long-term confinement. This ring comprises 120 permanent hexapole Halbach array magnets that guide the beam using inhomogeneous magnetic fields. Ultimately, we plan to install CRES measurement modules within this ring. The detailed design of this magnetic storage ring, and the results of numerical particle trajectory calculations for hydrogen and tritium atoms will be presented.
To allow in-situ measurement of magnetic and electric fields in the CRES modules within this apparatus, we have recently demonstrated the use of circular Rydberg states for absolute magnetometry, magnetic gradiometry and vector electrometry. Results from this work will also be summarised.
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 different applications. The aim of the ELECTRON project is to demonstrate, for the first time, that MMC based detectors can be employed for a high resolution spectroscopy of external electron sources, namely electron-gun, Kr-83m and tritium.
As MMC-based detectors have never been used for measurements of light charged particles, understanding the interplay between the detector and the external electrons is of crucial importance. To this end, electron-gun, which offers a possibility to easily adjust the rate and the energy of the electrons, and Kr-83m, with its well defined spectral lines, will allow for a proper characterisation and calibration of the detectors. Once the detector behaviour is well understood and characterised, newly developed tritium sources will be employed for the first ever measurements of the tritium $\beta$-decay spectrum with a cryogenic microcalorimeter.
Technology and methods developed within the context of the ELECTRON project will pave a way for the next generation neutrino experiments with tritium, employing a differential detector based on quantum technology. Possible future applications include the potential next phase of the KATRIN neutrino mass experiment, aiming at sub-200 eV sensitivity to electron (anti-)neutrino mass, as well as the detection of the cosmic neutrino background.
Undoubtedly, application scope of such technology goes well beyond neutrino physics and will allow for completely new and ground-breaking experiments in both particle and in astroparticle physics.
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 $\beta$-spectrum which manifests as a kink in the differential spectrum. The position and amplitude of this kink correspond to the sterile neutrino mass $m_4$ and effective mixing angle $\sin^2(\theta) = |U_{e4}|^2$, respectively. In this work sensitivity studies to light sterile neutrinos based on new science runs and the effect of systematic uncertainties are presented. A grid scan is performed in the [$m_4^2$, $\sin^2(\theta)$] 2-D plane using the fitting tool "KaFit" and neural network "Netrium" and sensitivity contours are calculated within this parameter space. The obtained sensitivity is compared to current results and anomalies in the field of light sterile neutrinos.
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, which additionally generate He3+ atoms and electrons. The neutrino mass requires a fixed amount of rest energy, thus this section is not available to be converted into kinetic energy. The remaining kinetic energy is then arbitrarily distributed over the decay products. Therefore, the electrons‘ spectrum is measured around its endpoint, as the maximum electron energy (i.e. all kinetic energy is stored in the electron) is reduced by the mass of the neutrino.
By the end of measurement planned for KATRIN, the experiment aims to reach a sensitivity of $m_{\nu}<0.2\,\text{eV}$. However, the neutrino mass might not be discovered within the experiment's lifetime. Considering the theory of particle physics, the smallest allowed effective neutrino mass, depending on the hierarchy, results in 50$\,$meV (9$\,$meV) for inverted (normal) ordering. Furthermore, cosmology predicts values, highly dependent on the model used as a base for data analysis, and significantly below the KATRIN results.
This shows that by the end of KATRIN, the direct, model-independent search for the neutrino mass is not yet exhausted. The KATRIN collaboration continuously works on improvements and better understanding of the experiment's setup, while also having an increasing interest in future adjustments when planning the next decades for this research facility.
As being adaptable is of high importance, cutting-edge technology is not left out of sight while investigating the options of improving the neutrino source and the electron detector. Conceptual studies on the impact of a high-resolution detector are performed, additionally exploring the potential of using atomic tritium in place of the current molecular source. These studies take into account fundamental characteristics of these changes. They will explore and provide the demands on hardware technology to reach the future goal, determined by combining the studies' result as well as upcoming development in hardware technology. On this poster the simulation software is introduced and first results on possible neutrino mass sensitivities are presented.
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 the physical boundary of the tritium source. This so-called Rear Wall is exposed to tritium, which leads to ad- and absorption. This in turn leads to systematic uncertainties for the neutrino mass measurements that need to be understood and mitigated. In maintenance phases, during which the gaseous tritium source was emptied (<10$^{−5}$ of nominal gas density), the activity accumulated on the Rear Wall during normal operation was monitored using β-induced X-ray spectrometry (BIXS) and direct observation of emitted β-electrons with a silicon detector. The
dependency of the observed activity increase on the integral tritium throughput was investigated and found to converge from a limited exponential growth to a continuous linear growth. This poster gives an overview of the results we obtained using several methods of in-situ decontamination of the Rear Wall while continuously monitoring the activity. The decontamination methods included
heating during continuous evacuation, flushing the system with nitrogen, deuterium or air with residual humidity at different pressures and illumination of the Rear Wall with UV-light. These well-known methods led only to a small (≈ 15%) decrease in the observed activity. However, a decrease of the surface activity by three orders of magnitude in less than a week was achieved by
combination of different methods using UV light, a heated surface and a low (5 mbar–100 mbar) pressure of air inside the chamber, leading to the production of highly reactive ozone. This proved to be by far the most efficient method, drastically reducing the contribution of the Rear Wall surface activity to the β-spectrum of the gaseous source.
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 analytic tools used in process monitoring. In the case of the KATRIN experiment, adsorbed tritium is regularly removed from the "Rear Wall" located inside its tritium source, since it contributes to the systematic uncertainty on the tritium $\beta$-spectrum. This is done in-situ via UV/ozone cleaning, which is a method that has been mentioned in literature multiple times. However, the underlying mechanism leading to the decontamination effect is not yet well understood. To investigate this mechanism systematically and to optimise the decontamination procedure, the UV ozone (UVO) experiment was set up. Carried out in a controlled environment, its purpose is to explore the production and depletion rates of ozone, as well as chemical processes between contaminated surfaces, ozone, and flushing gases like N2, H2, D2 and others with spectroscopic tools. This poster gives an overview of the UVO experiment and presents first quantitative results of the pressure dependence of ozone production and depletion rates in synthetic air.
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 retarding potential of the filter are counted at the detector at the end of the MAC-E spectrometer. In order to give students the opportunity to learn more about the experimental principles behind KATRIN, a smaller version of the MAC-E filter setup, called MiniMACE, has been built, which will be used in the advanced physics lab course at KIT. With a scale of approximately 1:20 the MiniMACE experiment includes all the major components of KATRIN: a tritium source, the spectrometer with adjustable high voltage, a high resolution detector and the magnetic guiding field. Other than KATRIN, the source uses two implanted disks with tritium and 83𝑚𝐾𝑟 that can be exchanged inside the ultra-high vacuum source chamber. This poster shows the design of the physics lab setup and reports on first results. This project has been supported by RIRO (Research Infrastructure in Research- Oriented teaching), which is part of the ExU project at KIT.
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 increase in statistics allow us to expand this reach. Our poster displays the KATRIN neutrino mass analysis and provides insight into the neutral network approach used to perform the computationally challenging analysis.
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 can be determined by measuring integral (standard spectrometer mode) or differential (time-of-flight mode) transmission spectra using a pulsed mono-energetic and mono-angular electron beam which is guided through the whole tritium source. The electron beam is produced by a recently upgraded photo-electron source providing energies up to 27 keV, with an energy resolution of <0.1 eV. The poster presents measurements for the determination of the energy-dependent energy-loss function in molecular tritium gas with high purity which were recently taken with the new photo-electron source at KATRIN.
This work is supported by BMBF under contract number 05A20PMA and Deutsche Forschungsgemeinschaft DFG (Research Training Group GRK 2149) in Germany.
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 fusion science and particle physics experiments. We have now developed a Cryogenic Viscosity Measurement Apparatus (Cryo-ViMA), based on a spinning rotor gauge (SRG), with which we are able to measure the viscosity of tritium between 77 K and 300 K, with an uncertainty of 2 % without any systematic corrections. By including systematic corrections concerning the temperature and the pressure, the uncertainty on the measurements can even be reduced down to 1 %. This poster presents the final setup, the measurement procedure and first results from the cold commissioning in a narrow temperature range.
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 plasma-facing surface area. Of the three liquid coolants supported (Li, LiPb, FLiBe), the LiPb loop will be connected first, with an inventory of 100 litres. A uniform magnetic field of up to 4 T can be generated with a pair of NbTi magnets for liquid metal magneto hydrodynamics testing. A plasma exhaust pumping system for the inner fuel cycle, direct internal recycling, a fuel clean-up system, tritium extraction from the coolant, and storage will be integrated into one system, using deuterium as a proxy for tritium. As future iterations of UNITY will use tritium for fuel cycle demonstration, we conduct a safety evaluation of a hypothetical tritium release in accidental conditions, assuming the use of deuterium and tritium instead of only the deuterium proxy. The safety assessment goal for UNITY is to demonstrate that it can be easily sited in Japan (or another country), without public health and environmental concerns, or the need for any emergency planning. We employ proven risk assessment methodologies to select the most representative accident scenario in terms of potential consequences. From this scenario, we estimate the quantity of radioactive materials that could be released from a simplified loop. We also undertake a literature review of the likely tritium release fraction that is then used in the assessment. Finally, we perform a sensitivity analysis to identify the most impactful parameters, enabling us to make design-impacting decisions and proportionate safety systems.
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 isomers is much smaller than that of different isotopologues and therefore the concentration gradients along a distillation column are way smaller. Therefore, this can be used for high accurate measurement of the HETP of distillation column.
In addition, this also enables to produce high purity ortho or para samples. Typically, only the ground state can be achieved in high purity by cooling down and catalysing. The room temperature equilibrium of 75% ortho H2 and T2 (66% para for D2) can not be exceeded by this procedure, but the application of cryogenic distillation enables the generation of such unique samples. Those samples above the thermal equilibrium come to interest when investigating the fundamental properties like molecular interaction and thermodynamic properties in dependence of the ortho para ratio of H2, T2 and D2.
This contribution shows the current state of simulation and experiments of ortho para distillation at TLK.
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 species. Therefore, a suitable CRM has to (i) comply with tritium-safety regulations, (ii) should have a minimal number of parts exposed to contamination, and (iii) can allow for future integration into a tritium glovebox system.
In this work, the setup and the design of a self-built CRM are presented, as well as selected characterization and Raman imaging measurements. Additionally, the status of a graphene-loading chamber with in-situ resistivity and temperature measurements is shown.
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 simulate many areas of our proposed experiment, from the motion of electrons in electric and magnetic fields, to signal identification amongst a variety of noise backgrounds.
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 $\approx 0.1\,\mathrm{eV \, c^{-2}}$.
One approach to overcome this molecular barrier is to use atomic tritium sources for future experiments.
This poster presents studies and developments with the aim to determine how an atomic hydrogen source can be operated, characterized, and scaled up.
In the first iteration, an off-the-shelf source (Tectra H-flux) is commissioned in a test setup.
With this, a basic understanding of the system behavior and atomic hydrogen production was developed.
In addition, the status of design and implementation of a system which is capable to handle tritium is presented.
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 have encountered challenges due to dispersive line shapes with multiple interpretations [6,7], restricting the precision of determining molecular vibrational level splittings. However, comparisons of numerous P and R lines have enabled the determination of highly accurate rotational level splittings [7].
Incorporating tritium-containing isotopologues in QED tests of hydrogen species provides new perspectives and deepens our understanding of these systems. Coherent Anti-Stokes Raman spectroscopy (CARS) has recently been utilized to measure vibrational splitting in T2, HT, and DT [8], albeit with an accuracy limited to a few MHz. We aim to significantly enhance the accuracy by employing our developed NICE-OHMS technology to measure the HT overtone spectrum. We have developed a specialized setup for HT spectroscopy under radiation safety conditions. Loading and handling the HT gas is done by employing an non-evaporable getter. We present the newest results from this nowel setup.
[1] C. Cheng, J. Hussels, M. Niu, H.L. Bethlem, K.S.E. Eikema, E.J. Salumbides, W. Ubachs, M. Beyer, N. Hoelsch, J.A. Agner, F. Merkt, L.G. Tao, S.M. Hu, C. Jungen, PRL 121, 013001 (2018)
[2] J. Komasa, M. Puchalski, P. Czachorowski, G. Lach, K. Pachucki, Phys. Rev. A 100, 032519 (2019).
[3] M. Puchalski, J. Komasa, A. Spyszkiewicz, and K. Pachucki, Phys. Rev. A 100, 020503(R) (2019).
[4] F.M.J. Cozijn, P. Dupre, E.J. Salumbides, K.S.E. Eikema, W. Ubachs. PRL 120, 153002 (2018).
[5] L.G. Tao, A.W. Liu, K. Pachucki, J. Komasa, Y.R. Sun, J. Wang, S.-M. Hu, PRL 120, 153001 (2018).
[6] Y.N. Lv, A.W. Liu, Y. Tan, C.L. Hu, T.P. Hua, X.B. Zou, Y.R. Sun, C.L. Zou, G.C. Guo, S.M. Hu, PRL 129, 163201 (2022).
[7] M.L. Diouf, F.M.J. Cozijn, V. Hermann, E.J. Salumbides, M. Schloesser, W. Ubachs, Phys. Rev. A 105, 062823 (2022).
[8] K.F. Lai, V. Hermann, T.M. Trivikram, M.L. Diouf, M. Schloesser, W. Ubachs, E.J. Salumbides, Phys. Chem. Chem. Phys. 22, 8973-8987 (2020).
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 reaction chains, and thus are of particular interest. Here we describe the controlled production of CQ4 carried out in the CAPER facility of the Tritium Laboratory Karlsruhe, exploiting catalytic reactions and species enrichment via the CAPER integral permeator. CQ4 was generated in substantial quantities 15 (>1000 cm3 at ~850 mbar, with CQ4content of up to ~20%). The samples were analyzed using laser Raman and mass spectrometry to determine the relative isotopologue composition and to trace the generation of tritiated chain hydrocarbons. Keywords — Tritium-substituted methane, mass spectrometry, Raman spectroscopy, measurement and monitoring.
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 flexibility. With the collected experience as well as the existing present infrastructure, TLK is very adapt competent in setting up tritium experiments. All facilities built at TLK need have dto go through an administrative- and technical- documentation process aiding and accompanying design, setup and commissioning.
This contribution shows the typical steps involved in the setup of a tritium facility at TLK.
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 Tritium Neutrino (KATRIN) experiment currently investigates the endpoint region of the tritium beta-decay spectrum to measure the effective electron anti-neutrino mass. The main objective of the TRISTAN project is to extend this energy range to measure the entire beta-decay spectrum. To this end, a novel multi-pixel silicon drift detector and readout system is currently being developed which enables the search for sterile neutrinos in the keV-mass range. This poster will give an overview on the design and development of the new detector and show first test measurements of a detector module.
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 the start of the tritium operation of KATRIN back in May 2018, more than 700 days of 24/7 measuring campaigns with a total tritium throughput of more than 22 kg and a tritium concentration > 95 % were conducted. Despite several technical challenges occurring during the runtime, the necessary reliable supply of tritium was provided.
This contribution will give an overview of the current operational conditions of the Tritium Laboratory Karlsruhe (TLK) tritium facilities involved, as well as an overview of selected technical challenges we faced during the runtime.
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.
Near-term fusion reactor concepts are based on the fusion of deuterium-tritium in a magnetic confinement configuration. While deuterium is abundant in nature, tritium is virtually non-existent and it is, at the moment, only a man-made by-product of some specific types of fission reactors. The current global inventory of man-made tritium is very scarce and keeps diminshing in time due to the decaying nature (half-life of around 12 years) of this isotope. Therefore, tritium has to be bred in-situ in a fusion reactor in order to guarantee its fuel self-sufficiency. The tritium breeding is one of the key functions of the Breedign Blanket (BB), which constitutes the core of a D-T fusion reactor. Other key functions of the BB is the production of high grade heat for electricity production and the contribution to shielding of the vacuum vessel and superconducting magnets.
This contribution gives an overview on the key role of the Breeding Blanket in a fusion reactor, its possible architectures, associated Tritium Extraction and Removal (TER) systems technologies and describes the main EU candidate BB concepts being considered for the EU DEMOnstration fusion reactor.
The design of ITER/DEMO tritium processing systems should benefit from experimental data and process validation on experimental facilities that are relevant from size and operational parameters point of view. Several rigs and experimental facilities have been developed or are under development in order to characterize different materials and components for some ITER and DEMO Tritium Plants like packings for ITER WDS (Water Detritiation System) or zeolites for DEMO Helium Cooled Pebble Bed Tritium Extraction and Recovery system. Beside the experimental activities, several design activities have been performed with respect to the two systems. The main achievements concerning the R&D and design activities with contribution from ICSI and KIT are introduced.
Tritium self-sufficiency is one of the big challenges of a DEMO power plant. This means that the efficiency of all the aspects related to tritium production, recovery and processing must be improved and, at the same time, all possible losses and inventories must be reduced. The nuclear fusion technologies division of the ENEA FSN department is very active on these topics. This talk illustrates some of the activities currently carried out at ENEA Frascati and Brasimone mainly inside EUROfusion work packages named WPTFV and WPBB.
In the WPTFV, most of the work is dedicated to the design of the so-called DEMO outer tritium plant loop (OUTL). Compare with the others two loops of DEMO fuel cycle, the direct (DIRL) and the inner (INTL), the OUTL is the one that has most similarities with the processes inside the ITER fuel cycle since contains the systems to detritate water, to separate the hydrogen isotopes and process the exhaust gases prior their release. However, significant differences arise due to the presence of the blanket and the coolant. Referring to the coolant, the talk addresses the problem of tritium permeation and the activities carried out to mitigate this issue. Inside the WPBB, ENEA leads the activities related to the development of the water cooled lithium-lead (WCLL) blanket. In this regard, the talk shows the experiments dedicated to study the hydrogen properties inside the lead-lithium alloy and the activities to realize efficient technologies for tritium extraction from lead lithium.
The Fusion Materials Laboratory (FML) is a unique facility providing experimental techniques for the investigation of radioactive and toxic materials. Its main purpose is the development and qualification of functional and structural materials for fusion power plants. Consequently, the interaction of tritium with these material classes is one of the core research topics at the FML.
The talk will start with a short introduction to the instrumentation at the FML. Subsequently, examples for the global measurement of the tritium release of lithium orthosilicate-based breeder pebbles and the local measurement of tritium adsorption and segregation with near-atomic resolution will be presented. Finally, in an outlook we will shine light on the future of tritium research in the ERC funded Consolidator Grant “TRITIME” as well as currently envisaged future characterization techniques for tritium research.
Hydrogen's three naturally occurring isotopes, protium (H), deuterium (D) and tritium (T) lie at the focus of the DFG Research Training Group 1,2,3H (RTG 2721), which combines the expertise of Leipzig University, the Helmholtz-Zentrum Dresden-Rossendorf/Research Site Leipzig, and the Leibniz Institute of Surface Engineering in the fields of laser spectroscopy, materials science, lab-on-a-chip technology, advanced organic synthesis and radiochemistry. Our research and training programme is aimed at gaining an atomic-level understanding of nuclear quantum effects in nanostructured materials and nH-bonded networks in order to develop enabling technologies for H/D/T separation using porous materials, electrocatalytic D/T labelling and microscale T detection.
We have designed and build a new setup at the Tritium Laboratory Karlsruhe (TLK) for the measurement of the Sieverts-constant of lithium-lead (PbLi) with tritium. To reduce the systematic impact of hydrogen solubility in different materials, we used aluminium and glass parts for the majority of the setup choosing stainless steel only where no alternatives are available. Combined with a careful design and layout of all internal volumes and variable buffer vessel sizes combined with a flexible PbLi amount of 100 g or 1000 g, the setup provides high-sensitivity access to a broad range of possible Sieverts-constants. The symmetric layout of the feed and extraction side aims for both, adsorption and desorption measurements with high sensitivity in a wide range of Sieverts-constants mentioned in literature.
A second key feature for a successful determination of the Sieverts-constant is the handling of the lithium lead. Impurities such as oxides can have a great impact on the performance of the facility as well as on the Sieverts-constant itself. Therefore, methods for cleaning, storage and transfer have to be tested and defined.
In this contribution we will present the current status of the experiment including details on the design considerations. In addition, we show the efforts made to obtain best possible sample preparation for the lithium-lead used. This will be accompanied by an extensive series of commissioning measurements with hydrogen which are an absolute necessity to gain a deep understanding of the systematic effects of the facility prior to contamination with tritium.
JET has recently completed the second Deuterium/Tritium Campaign at JET (DTE2). Initiated in September 2020, it was the first experimental campaign since 2003, and the first major one since DTE1 in 1997. This has induced a lot of challenges for the Tritium Innovation Unit members, in charge of the recommissioning and operation of the Active Gas Handling System (AGHS). This presentation will present these challenges as well as some lessons learnt.
The presentation will provide a general overview of CNL, what we do and the recent major investments happening in the laboratories. An overview of the tritium and heavy water management, process and separation experience will follow, including an exciting description of the newly proposed Heavy Water Detritiation Facility. The HWDF is expected to be built in the next 2 to 3 years, using CNL hydrogen isotopes technology. A short description of new initiatives to separate deuterium and tritium gases using cryogenic distillation of thermal cycling absorption will also be given. Finally, the presentation will conclude with the newest program of work that incorporates tritium in the fusion fuel cycle and the opportunities that CNL is pursuing with its partners, showing its first-of-a-kind fully integrated fuel cycle demonstration facility.
Since starting operation in 1993 the Tritium Laboratory Karlsruhe (TLK) has developed into a unique pilot scale isotope laboratory focused on tritium handling and processing to conduct a variety of scientific experiments and development tasks.
While TLK was initially focused to develop technical tritium handling techniques and processes in view of the fuel cycle in future fusion power plants (development of processes and components for detritiation of gases expected from tokamak exhaust, development of a combined water detritiation and cryogenic distillation system and the application of different methods for tritium analytics), the current mission is to host the tritium source of the Karlsruhe Tritium Neutrino experiment (KATRIN), which will use tritium for direct measurement of the absolute mass of the electron (anti)neutrino, employing precise spectroscopy of the tritium β-spectrum close to the maximum energy of 18.6 keV.
In order to fulfil this mission, TLK currently operates a dedicated semi-technical-scale tritium- infrastructure for reliable and modular tritium confinement and processing. This system is comprising of tritium storage & delivery, isotope recovery and isotope separation, housed in 15 glove boxes of ~125 m³ total volume.
A set of regulations is applied as a basis for the operation of TLK, resulting in a regulatory framework of operation in view of licensing as well as administrative and technical regulations, that ensure a both safe and flexible environment, to legally and reliably operate an isotope laboratory of this scale.
This contribution will give an overview of both the past and current state of the TLK tritium infrastructure operations, as well as lessons learned.
Robert MICHLING, Ian BONNETT, David DEMANGE, Wataru SHU, Peter SPELLER, Scott WILLMS
ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul Lez Durance Cedex – France
Corresponding author: Robert.michling@iter.org
ITER is a joint international research and development project that aims to demonstrate the scientific and technical feasibility of fusion power. When ITER uses the real fusion fuel during operations — a mixture of deuterium and tritium — part of this fuel will not be burned. This leads to an exhaust mixture of fusion fuel, helium and other impurities, which needs to be processed at unprecedented flow rates by the Tritium Plant within the Fuel Cycle, with measures necessary for the confinement and safe handling of tritium.
The ITER Tritium Plant systems are a complicated and complex collection of small scale chemical plant sub-systems, utilising specialist technology with multiple confinement barriers. It uses well-proven fusion technologies and equipment (catalytic reactors, permeators, cryogenic distillation, chemical exchange columns, electrolysers, gas distribution, etc.), deployed at a larger scale than previously used.
For the operation and safety aspects the Tritium Plant systems have specific needs of analytical capabilities in view of hydrogen isotope measurements (absolute/relative) for online process control functions, as well for precise composition measurements linked to accountancy tasks within the facility. The detection of impurities in the hydrogen gas streams are also crucial for indication of healthy process conditions and off-sets events. The range of hydrogen isotope fractions to be analysed within gases or of water stretch from pure to ppt levels, which can only be covered by the implementation of different analytical technologies and measurement conditions to fulfil the needs of the Tritium Plant.
The presentation will give an overview of the different Tritium Plant systems under the most common operating conditions linked to individual analytical requirements. Also it will highlight available analytical technologies and identify areas of missing analytical performances to be resolved in future for a successful and safe operation of the Fuel Cycle of ITER.
“The views and opinions expressed herein do not necessarily reflect those of the ITER Organization.”
©2023, ITER Organization
The focus of the Tritium Laboratory Karlsruhe (TLK) is tritium R&D in support of a wide field of applications like neutrino mass measurement with KATRIN and the Fusion fuel cycle. One key aspect is tritium analytics, a broad and multifaceted field that can be sorted in many different ways. One useful way to group the analytic tools is by the properties of the tritium sample like its state of aggregation, the molecular state (e.g. elemental, water, tritiated carbon hydrogens and so on) or composition (like tritium traces in water or helium, pure hydrogen istopologues and so on). Another grouping is by the gathered information, e.g. total activity, total heat of decay, molecular composition etc. This kind of sorting will always be difficult, because this will open up many side conditions for a proper screening. In this contribution we are sorting by the order of magnitude of tritium density that the analytic tool can handle. Starting from a very high density with IR spectroscopy, that can be used for elemental solid and liquid Tritium like it is used in pellet production for fusion fuelling and isotope separation by cryogenic distillation. Passing several orders of magnitude with techniques like Raman spectroscopy and beta induced X-ray spectroscopy; which are for example used in inline process monitoring of KATRIN. Down to rare traces of tritium measured with scintillation counting like it is required in dual phase xenon time projection chambers in the search of ultra-rare physics.
In the framework of H2020 Euratom research and innovation programme, TRANSAT (TRANSversal Actions for Tritium) is a 54 months multidisciplinary project built to contribute to Research and Innovation on cross-cutting activities required to improve and disseminate knowledge on tritium management in fission and fusion facilities. TRANSAT has started in 2017 and was built to answer the main following challenges:
• tritium release mitigation strategies,
• waste management improvement,
• refinement of the knowledge in the field of radiotoxicity, radiobiology and dosimetry,
• promote the knowledge dissemination about tritium management.
To evaluate the scientific tasks to be covered in TRANSAT, all the open issues at each step of the tritium life cycle that have not yet been addressed within European research programs or in previous studies have been analyzed. This general landscape has been focused on crosscutting activities on fusion and fission.
The aim of this presentation is to give a general overview of the major outcomes of the technical topics that have been covered by the eighteen partners of the project.
In particular, this paper will focus on:
• the development and test of new permeation barriers,
• the control of online tritium effluents by innovative technical solution,
• the development of new diagnostics for tritiated Low Level Wastes characterization
• the improvement of the modelling tools of tritium migration in fusion/fission reactors.
In addition, part of the project deals with radiotoxicity, radioecology, radiobiology and dosimetry on tritiated particles produced during dismantling, whose impacts have never been addressed before. The results of these activities will be also presented.
Hydrogen Isotope Research Center (HRC), University of Toyama, Japan has been licensed to use 8 TBq of tritium per day. This handling capability of tritium allows to perform investigations on tritium measurements, tritium-material interactions and preparation of tritiated targets for nuclear reaction studies. The objective of this presentation is to introduce several tritium measurement techniques developed in HRC together with recent activities on tritium target fabrication.
β-ray induced x-ray spectrometry (BIXS) has been developed in HRC [1]. The escape depth of β-rays from tritium in a solid are just a few hundred nanometers to a few micrometers, depending on density of the solid. Hence, it is difficult to measure tritium content in a solid and that in gas and liquid phases from outside of a container by β-ray counting. Nevertheless, interactions between β-rays and matters result in generation of bremsstrahlung and characteristic x-rays. Because of far larger escape depths of x-rays than β-rays at the same energy, tritium content in a solid sample can be evaluated by x-ray measurements. Non-destructive depth profiling is possible by analysing x-ray spectrum with consideration of generation and attenuation of x-rays in a sample. A thin beryllium windows covered by high-Z material layer allows the evaluation of tritium content in gas and liquid phases from outside of the container.
HRC also developed a high sensitivity calorimeter capable to evaluate the amount of tritium as low as 40 MBq [2]. In Japan, the amount of tritium allowed to handle without control by regulations is limited to be less than 1 GBq. However, it is difficult to evaluate and control tritium content in imported products. This calorimeter is helping the security authority of Japan via non-destructive measurement of tritium content in imported products.
Dr. K. Miki in Tohoku University, Japan, has proposed to study multi-neutron systems using nuclear reactions of tritium. A self-standing Ti tritide target was prepared in HRC through the collaboration of Dr. Miki and researchers in HRC. Ti tritide targets supported by Cu plates were also prepared for 14 MeV neutron generator. HRC is currently the sole provider of tritide targets in Japan.
[1] M. Hara et al., Fusion Eng. Design 119 (2017) 12-16 and references there in.
[2] M. Matsuyama and M. Hara, Fusion Sci. Technol. 54 (2007) 16–21.
Raman spectroscopy has become one of the cornerstones of laser analytical methods to identify, and quantify, chemical compounds, and for use in determining material composition. Its great advantages are that (i) only one a single, fixed-wavelength laser is required; (ii) any molecular compound can be investigated, even in multi-component mixtures; (iii) any type of material can be probed, irrespective of aggregate state – gaseous, liquid or solid; and (iv) the analysis can be carried out contactless, in situ and with spatial resolution, if required.
After a brief introduction into the principles of Raman spectroscopy, a few key examples from operations at TLK will be discussed – ranging from fundamental science to chemical process control, and applications to surface science.
This is a joint session between two workshops which run in parallel
a) Symposium „30 Years of Tritium Laboratory Karlsruhe“ at Karlsruhe, Germany
b) Fusion Fuel Cycles and Blankets Workshop 2023 at Charlotte, USA
There is growing excitement about fusion energy as an option to contribute to the world’s low-carbon energy supply. Increasing numbers of private companies are aiming to deliver commercial fusion and are producing significant breakthroughs in the science and technology that will lead to a commercial power plant.
The Fusion Industry Association (FIA) is the unified voice of the fusion industry, working to transform the energy system with commercially viable fusion power. Founded as an initiative in 2018, the FIA has already made its mark in Washington and around the world. As it expands, the FIA will support the creation of a new industry that will change the world.
Decades of worldwide, government-sponsored research in fusion science have established the tokamak-based configuration as the leading approach to confining fusion-grade plasmas with strong magnetic fields. Yet, in the past, even state-of-the art superconducting magnet technology required tokamaks to be enormous to produce net fusion energy. Recently, a new high temperature superconductor has reached industrial maturity. CFS is using these high temperature superconductors to build smaller and lower-cost tokamak fusion systems. CFS will build first-of-its-kind high temperature superconducting magnets, followed by the world’s first net energy-producing fusion machine, called SPARC. SPARC will pave the way for the first commercially viable fusion power plant, called ARC. CFS has assembled a world-class team working to design and build fusion machines that will provide limitless, clean, fusion energy to combat climate change.
Public funded fusion experiments have stalled in recent years for several reasons. ITER is around 10 years away and Demo around 30 years. This timeline brings commercial fusion power plants to the grid by the end of this century.
Private fusion companies closing this gap and their mission is to provide commercial clean, sustainable and low carbon energy to the grid much earlier.
Tokamak Energy was founded in 2009 and has a road map to a pilot power plant in the 2030s.
The European startup Renaissance Fusion synergistically combines three main pillars: the stellarator, High Temperature Superconductors (HTS) and liquid metal walls. For simpler coil manufacturing, Renaissance is building machines to directly deposit HTS on large 2D surfaces. Engraving imposes specific current-patterns that generate specific 3D magnetic fields. Plasma-facing, liquid metal walls will be thick enough to shield structural materials and delicate HTS from fusion neutrons, yet not too thick, thanks to neutron-attenuating hydrides. The walls will flow, hence extract heat, and will contain lithium, hence breed tritium. Experiments are well on track to prove thick, free-surface liquid metal flows adhering to the interior of cylindrical chambers by means of electromagnetic and centrifugal forces, initially without plasmas. For initial experiments, the dense GaInSn alloy is being used, at room temperature. This will give confidence on the ability to sustain and stabilize flows of lighter fluids. Subsequently, we will adopt lighter, fusion-relevant materials and temperatures. A remarkably simple tritide extraction technique will be presented, based on phase transitions in solutions of lithium with its hydrides. Research needs, job openings and areas of possible collaboration will also be discussed.
The Institute for Astroparticle Physics (IAP) operates the European Tritium Laboratory Karlsruhe (TLK), a semi-technical scale facility for processing tritium, the radioactive hydrogen isotope. Its license to handle up to 40 grams of tritium, its present site inventory of about 30 grams of tritium, and its extensive infrastructure and experimental apparatus, make it a favorable location to contribute to research and developments for nuclear fusion research.
More than 20 glove box systems, total volume of about 190 m³, are operated in an area of 1600 m² for experiments and infrastructure facilities. The TLK can look back on a history of more than 30 years of safe operation and experience with tritium.
In this talk we will summarize possible opportunities by the TLK for the public-private R&D initiatives in the field of nuclear fusion.