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Start Over Author "A. Lokhov" Publisher escholarship, university of california
25 results on '"A. Lokhov"'

1. Direct neutrino-mass measurement based on 259 days of KATRIN data

Author

Aker, M, Batzler, D, Beglarian, A, Behrens, J, Beisenkötter, J, Biassoni, M, Bieringer, B, Biondi, Y, Block, F, Bobien, S, Böttcher, M, Bornschein, B, Bornschein, L, Caldwell, TS, Carminati, M, Chatrabhuti, A, Chilingaryan, S, Daniel, BA, Debowski, K, Descher, M, Barrero, D Díaz, Doe, PJ, Dragoun, O, Drexlin, G, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Felden, A, Fengler, C, Fiorini, C, Formaggio, JA, Forstner, C, Fränkle, FM, Gauda, K, Gavin, AS, Gil, W, Glück, F, Grohmann, S, Grössle, R, Gumbsheimer, R, Gutknecht, N, Hannen, V, Hasselmann, L, Haußmann, N, Helbing, K, Henke, H, Heyns, S, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Höhn, T, Huber, A, Jansen, A, Karl, C, Kellerer, J, Khosonthongkee, K, Kleifges, M, Klein, M, Kohpeiß, J, Köhler, C, Köllenberger, L, Kopmann, A, Kovač, N, Kovalík, A, Krause, H, Cascio, L La, Lasserre, T, Lauer, J, Le, T, Lebeda, O, Lehnert, B, Li, G, Lokhov, A, Machatschek, M, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Mertens, S, Mohanty, S, Mostafa, J, Müller, K, Nava, A, Neumann, H, Niemes, S, Onillon, A, Parno, DS, Pavan, M, Pinsook, U, Poon, AWP, Poyato, JM Lopez, Pozzi, S, Priester, F, Ráliš, J, Ramachandran, S, Robertson, RGH, and Rodenbeck, C

Subjects
nucl-ex, hep-ex
Abstract

The fact that neutrinos carry a non-vanishing rest mass is evidence ofphysics beyond the Standard Model of elementary particles. Their absolute massbears important relevance from particle physics to cosmology. In this work, wereport on the search for the effective electron antineutrino mass with theKATRIN experiment. KATRIN performs precision spectroscopy of the tritium$\beta$-decay close to the kinematic endpoint. Based on the first fiveneutrino-mass measurement campaigns, we derive a best-fit value of $m_u^{2} ={-0.14^{+0.13}_{-0.15}}~\mathrm{eV^2}$, resulting in an upper limit of $m_u <{0.45}~\mathrm{eV}$ at 90 % confidence level. With six times the statistics ofprevious data sets, amounting to 36 million electrons collected in 259measurement days, a substantial reduction of the background level and improvedsystematic uncertainties, this result tightens KATRIN's previous bound by afactor of almost two.

Published
2024

2. Search for Lorentz-invariance violation with the first KATRIN data

Author

Aker, M, Batzler, D, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Block, F, Bobien, S, Bornschein, B, Bornschein, L, Böttcher, M, Brunst, T, Caldwell, TS, Carney, RMD, Chilingaryan, S, Choi, W, Debowski, K, Descher, M, Barrero, D Díaz, Doe, PJ, Dragoun, O, Drexlin, G, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gavin, AS, Gil, W, Glück, F, Grössle, R, Gumbsheimer, R, Hannen, V, Haußmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Höhn, T, Houdy, T, Huber, A, Jansen, A, Karl, C, Kellerer, J, Kleifges, M, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, La Cascio, L, Lasserre, T, Le, TL, Lebeda, O, Lehnert, B, Lokhov, A, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Mertens, S, Mostafa, J, Müller, K, Neumann, H, Niemes, S, Oelpmann, P, Parno, DS, Poon, AWP, Poyato, JML, Priester, F, Ráliš, J, Ramachandran, S, Robertson, RGH, Rodejohann, W, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Salomon, R, Schäfer, P, Schimpf, L, Schlösser, M, Schlösser, K, and Schlüter, L

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences
Abstract

Some extensions of the Standard Model of particle physics allow for Lorentz invariance and charge-parity-time invariance violations. In the neutrino sector strong constraints have been set by neutrino-oscillation and time-of-flight experiments. However, some Lorentz-invariance-violating parameters are not accessible via these probes. In this work, we focus on the parameters (aof(3))00, (aof(3))10, and (aof(3))11 which would manifest themselves in a nonisotropic β-decaying source as a sidereal oscillation and an overall shift of the spectral endpoint. Based on the data of the first scientific run of the KATRIN experiment, we set the first 90% confidence-level limit on |(aof(3))11| of

Published
2023

3. Search for keV-scale sterile neutrinos with the first KATRIN data

Author

Aker, M, Batzler, D, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Block, F, Bobien, S, Bornschein, B, Bornschein, L, Böttcher, M, Brunst, T, Caldwell, TS, Chilingaryan, S, Choi, W, Debowski, K, Descher, M, Barrero, D Díaz, Doe, PJ, Dragoun, O, Drexlin, G, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gavin, AS, Gil, W, Glück, F, Grössle, R, Gumbsheimer, R, Hannen, V, Haußmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Höhn, T, Houdy, T, Huber, A, Jansen, A, Karl, C, Kellerer, J, Kleifges, M, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, La Cascio, L, Lasserre, T, Le, TL, Lebeda, O, Lehnert, B, Lokhov, A, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Mertens, S, Mostafa, J, Müller, K, Neumann, H, Niemes, S, Oelpmann, P, Parno, DS, Poon, AWP, Poyato, JML, Priester, F, Ráliš, J, Ramachandran, S, Robertson, RGH, Rodejohann, W, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Salomon, R, Schäfer, P, Schimpf, L, Schlösser, M, Schlösser, K, Schlüter, L, and Schneidewind, S

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

In this work we present a keV-scale sterile-neutrino search with a low-tritium-activity data set of the KATRIN experiment, acquired in a commissioning run in 2018. KATRIN performs a spectroscopic measurement of the tritium β -decay spectrum with the main goal of directly determining the effective electron anti-neutrino mass. During this commissioning phase a lower tritium activity facilitated the measurement of a wider part of the tritium spectrum and thus the search for sterile neutrinos with a mass of up to 1.6keV . We do not find a signal and set an exclusion limit on the sterile-to-active mixing amplitude of sin 2θ< 5 × 10 - 4 (95 % C.L.) at a mass of 0.3 keV. This result improves current laboratory-based bounds in the sterile-neutrino mass range between 0.1 and 1.0 keV.

Published
2023

4. KATRIN: status and prospects for the neutrino mass and beyond

Author

Aker, M, Balzer, M, Batzler, D, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Biassoni, M, Bieringer, B, Block, F, Bobien, S, Bombelli, L, Bormann, D, Bornschein, B, Bornschein, L, Böttcher, M, Brofferio, C, Bruch, C, Brunst, T, Caldwell, TS, Carminati, M, Carney, RMD, Chilingaryan, S, Choi, W, Cremonesi, O, Debowski, K, Descher, M, Barrero, D Díaz, Doe, PJ, Dragoun, O, Drexlin, G, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Felden, A, Fink, D, Fiorini, C, Formaggio, JA, Forstner, C, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gavin, AS, Gil, W, Glück, F, Grande, A, Grössle, R, Gugiatti, M, Gumbsheimer, R, Hannen, V, Hartmann, J, Haußmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Höhn, T, Houdy, T, Huber, A, Jansen, A, Karl, C, Kellerer, J, King, P, Kleifges, M, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, Lasserre, T, La Cascio, L, Lebeda, O, Lechner, P, Lehnert, B, Le, TL, Lokhov, A, Machatschek, M, Malcherek, E, Manfrin, D, Mark, M, Marsteller, A, Martin, EL, Mazzola, E, Melzer, C, Mertens, S, Mostafa, J, Müller, K, Nava, A, Neumann, H, Niemes, S, Oelpmann, P, and Onillon, A

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, neutrino, neutrino mass, sterile neutrino, tritium beta decay, krypton, beyond standard model, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Nuclear and plasma physics, Particle and high energy physics
Abstract

The Karlsruhe Tritium Neutrino (KATRIN) experiment is designed to measure a high-precision integral spectrum of the endpoint region of T2 β decay, with the primary goal of probing the absolute mass scale of the neutrino. After a first tritium commissioning campaign in 2018, the experiment has been regularly running since 2019, and in its first two measurement campaigns has already achieved a sub-eV sensitivity. After 1000 days of data-taking, KATRIN’s design sensitivity is 0.2 eV at the 90% confidence level. In this white paper we describe the current status of KATRIN; explore prospects for measuring the neutrino mass and other physics observables, including sterile neutrinos and other beyond-Standard-Model hypotheses; and discuss research-and-development projects that may further improve the KATRIN sensitivity.

Published
2022

5. New Constraint on the Local Relic Neutrino Background Overdensity with the First KATRIN Data Runs

Author

Aker, M, Batzler, D, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Block, F, Bobien, S, Bornschein, B, Bornschein, L, Böttcher, M, Brunst, T, Caldwell, TS, Carney, RMD, Chilingaryan, S, Choi, W, Debowski, K, Descher, M, Barrero, D Díaz, Doe, PJ, Dragoun, O, Drexlin, G, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gavin, AS, Gil, W, Glück, F, Grössle, R, Gumbsheimer, R, Hannen, V, Haußmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Höhn, T, Houdy, T, Huber, A, Jansen, A, Karl, C, Kellerer, F, Kellerer, J, Kleifges, M, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, La Cascio, L, Lasserre, T, Le, TL, Lebeda, O, Lehnert, B, Lokhov, A, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Mertens, S, Mostafa, J, Müller, K, Neumann, H, Niemes, S, Oelpmann, P, Parno, DS, Poon, AWP, Poyato, JML, Priester, F, Ráliš, J, Ramachandran, S, Robertson, RGH, Rodejohann, W, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Salomon, R, Schäfer, P, Schimpf, L, Schlösser, M, and Schlösser, K

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, KATRIN Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

We report on the direct search for cosmic relic neutrinos using data acquired during the first two science campaigns of the KATRIN experiment in 2019. Beta-decay electrons from a high-purity molecular tritium gas source are analyzed by a high-resolution MAC-E filter around the end point at 18.57 keV. The analysis is sensitive to a local relic neutrino overdensity ratio of η

Published
2022

6. Improved eV-scale sterile-neutrino constraints from the second KATRIN measurement campaign

Author

Aker, M, Batzler, D, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Block, F, Bobien, S, Bornschein, B, Bornschein, L, Böttcher, M, Brunst, T, Caldwell, TS, Carney, RMD, Chilingaryan, S, Choi, W, Debowski, K, Descher, M, Barrero, D Díaz, Doe, PJ, Dragoun, O, Drexlin, G, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gavin, AS, Gil, W, Glück, F, Grössle, R, Gumbsheimer, R, Hannen, V, Haußmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Höhn, T, Houdy, T, Huber, A, Jansen, A, Karl, C, Kellerer, J, Kleifges, M, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, La Cascio, L, Lasserre, T, Le, TL, Lebeda, O, Lehnert, B, Lokhov, A, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Mertens, S, Mostafa, J, Müller, K, Neumann, H, Niemes, S, Oelpmann, P, Parno, DS, Poon, AWP, Poyato, JML, Priester, F, Ráliš, J, Ramachandran, S, Robertson, RGH, Rodejohann, W, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Salomon, R, Schäfer, P, Schimpf, L, Schlösser, M, Schlösser, K, and Schlüter, L

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Mathematical physics, Astronomical sciences, Particle and high energy physics
Abstract

We present the results of the light sterile neutrino search from the second Karlsruhe Tritium Neutrino (KATRIN) measurement campaign in 2019. Approaching nominal activity, 3.76×106 tritium β-electrons are analyzed in an energy window extending down to 40 eV below the tritium end point at E0=18.57 keV. We consider the 3ν+1 framework with three active and one sterile neutrino flavors. The analysis is sensitive to a fourth mass eigenstate m42≲1600 eV2 and active-to-sterile mixing |Ue4|2≳6×10-3. As no sterile-neutrino signal was observed, we provide improved exclusion contours on m42 and |Ue4|2 at 95% C.L. Our results supersede the limits from the Mainz and Troitsk experiments. Furthermore, we are able to exclude the large Δm412 solutions of the reactor antineutrino and gallium anomalies to a great extent. The latter has recently been reaffirmed by the BEST Collaboration and could be explained by a sterile neutrino with large mixing. While the remaining solutions at small Δm412 are mostly excluded by short-baseline reactor experiments, KATRIN is the only ongoing laboratory experiment to be sensitive to relevant solutions at large Δm412 through a robust spectral shape analysis.

Published
2022

7. Direct neutrino-mass measurement with sub-electronvolt sensitivity

Author

Aker, M, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Block, F, Bobien, S, Boettcher, M, Bornschein, B, Bornschein, L, Brunst, T, Caldwell, TS, Carney, RMD, La Cascio, L, Chilingaryan, S, Choi, W, Debowski, K, Deffert, M, Descher, M, Barrero, D Diaz, Doe, PJ, Dragoun, O, Drexlin, G, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Felden, A, Formaggio, JA, Fraenkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gil, W, Glueck, F, Groessle, R, Gumbsheimer, R, Gupta, V, Hoehn, T, Hannen, V, Haussmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Houdy, T, Huber, A, Jansen, A, Karl, C, Kellerer, F, Kellerer, J, Kleifges, M, Klein, M, Koehler, C, Koellenberger, L, Kopmann, A, Korzeczek, M, Kovalik, A, Krasch, B, Krause, H, Kunka, N, Lasserre, T, Le, TL, Lebeda, O, Lehnert, B, Lokhov, A, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Menshikov, A, Mertens, S, Mostafa, J, Mueller, K, Neumann, H, Niemes, S, Oelpmann, P, Parno, DS, Poon, AWP, Poyato, JML, Priester, F, Ramachandran, S, Robertson, RGH, Rodejohann, W, Roellig, M, Roettele, C, Rodenbeck, C, Rysavy, M, Sack, R, Saenz, A, Schaefer, P, Pollithy, A Schaller Nee, Schimpf, L, Schloesser, K, and Schloesser, M

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Mathematical Sciences, Fluids & Plasmas, Mathematical sciences, Physical sciences
Abstract

Since the discovery of neutrino oscillations, we know that neutrinos have non-zero mass. However, the absolute neutrino-mass scale remains unknown. Here we report the upper limits on effective electron anti-neutrino mass, mν, from the second physics run of the Karlsruhe Tritium Neutrino experiment. In this experiment, mν is probed via a high-precision measurement of the tritium β-decay spectrum close to its endpoint. This method is independent of any cosmological model and does not rely on assumptions whether the neutrino is a Dirac or Majorana particle. By increasing the source activity and reducing the background with respect to the first physics campaign, we reached a sensitivity on mν of 0.7 eV c–2 at a 90% confidence level (CL). The best fit to the spectral data yields mν2 = (0.26 ± 0.34) eV2 c–4, resulting in an upper limit of mν < 0.9 eV c–2 at 90% CL. By combining this result with the first neutrino-mass campaign, we find an upper limit of mν < 0.8 eV c–2 at 90% CL.

Published
2022

8. Analysis methods for the first KATRIN neutrino-mass measurement

Author

Aker, M, Altenmüller, K, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Blaum, K, Block, F, Bornschein, B, Bornschein, L, Böttcher, M, Brunst, T, Caldwell, TS, La Cascio, L, Chilingaryan, S, Choi, W, Díaz Barrero, D, Debowski, K, Deffert, M, Descher, M, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Fedkevych, M, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gil, W, Glück, F, Grössle, R, Gumbsheimer, R, Höhn, T, Hannen, V, Haußmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Houdy, T, Huber, A, Jansen, A, Köllenberger, L, Karl, C, Kellerer, J, Kippenbrock, L, Klein, M, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, Lasserre, T, Le, TL, Lebeda, O, Lehnert, B, Lokhov, A, Lopez Poyato, JM, Müller, K, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Mertens, S, Niemes, S, Oelpmann, P, Osipowicz, A, Parno, DS, Poon, AWP, Priester, F, Röllig, M, Röttele, C, Rest, O, Robertson, RGH, Rodenbeck, C, Ryšavý, M, Sack, R, Saenz, A, Schaller, A, Schäfer, P, Schimpf, L, Schlösser, K, Schlösser, M, Schlüter, L, Schrank, M, Schulz, B, and Šefčík, M

Abstract

We report on the dataset, data handling, and detailed analysis techniques of the first neutrino-mass measurement by the Karlsruhe Tritium Neutrino (KATRIN) experiment, which probes the absolute neutrino-mass scale via the β-decay kinematics of molecular tritium. The source is highly pure, cryogenic T2 gas. The β electrons are guided along magnetic field lines toward a high-resolution, integrating spectrometer for energy analysis. A silicon detector counts β electrons above the energy threshold of the spectrometer, so that a scan of the thresholds produces a precise measurement of the high-energy spectral tail. After detailed theoretical studies, simulations, and commissioning measurements, extending from the molecular final-state distribution to inelastic scattering in the source to subtleties of the electromagnetic fields, our independent, blind analyses allow us to set an upper limit of 1.1 eV on the neutrino-mass scale at a 90% confidence level. This first result, based on a few weeks of running at a reduced source intensity and dominated by statistical uncertainty, improves on prior limits by nearly a factor of two. This result establishes an analysis framework for future KATRIN measurements, and provides important input to both particle theory and cosmology.

Published
2021

9. Precision measurement of the electron energy-loss function in tritium and deuterium gas for the KATRIN experiment

Author

Aker, M, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Block, F, Bornschein, B, Bornschein, L, Böttcher, M, Brunst, T, Caldwell, TS, Carney, RMD, Chilingaryan, S, Choi, W, Debowski, K, Deffert, M, Descher, M, Barrero, D Díaz, Doe, PJ, Dragoun, O, Drexlin, G, Edzards, F, Eitel, K, Ellinger, E, Miniawy, A El, Engel, R, Enomoto, S, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gil, W, Glück, F, Groh, S, Grössle, R, Gumbsheimer, R, Hannen, V, Haußmann, N, Heizmann, F, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Höhn, T, Houdy, T, Huber, A, Jansen, A, Karl, C, Kellerer, J, Kleesiek, M, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, Kunka, N, Lasserre, T, La Cascio, L, Lebeda, O, Lehnert, B, Le, TL, Lokhov, A, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Meier, M, Melzer, C, Menshikov, A, Mertens, S, Mostafa, J, Müller, K, Niemes, S, Oelpmann, P, Parno, DS, Poon, AWP, Poyato, JML, Priester, F, Ranitzsch, PC-O, Robertson, RGH, Rodejohann, W, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Schäfer, P, Schaller, A, Schimpf, L, and Schlösser, K

Subjects
Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics
Abstract

AbstractThe KATRIN experiment is designed for a direct and model-independent determination of the effective electron anti-neutrino mass via a high-precision measurement of the tritium $$\upbeta $$ β -decay endpoint region with a sensitivity on $$m_\nu $$ m ν of 0.2 $$\hbox {eV}/\hbox {c}^2$$ eV / c 2 (90% CL). For this purpose, the $$\upbeta $$ β -electrons from a high-luminosity windowless gaseous tritium source traversing an electrostatic retarding spectrometer are counted to obtain an integral spectrum around the endpoint energy of 18.6 keV. A dominant systematic effect of the response of the experimental setup is the energy loss of $$\upbeta $$ β -electrons from elastic and inelastic scattering off tritium molecules within the source. We determined the energy-loss function in-situ with a pulsed angular-selective and monoenergetic photoelectron source at various tritium-source densities. The data was recorded in integral and differential modes; the latter was achieved by using a novel time-of-flight technique. We developed a semi-empirical parametrization for the energy-loss function for the scattering of 18.6-keV electrons from hydrogen isotopologs. This model was fit to measurement data with a 95% $$\hbox {T}_2$$ T 2 gas mixture at 30 K, as used in the first KATRIN neutrino-mass analyses, as well as a $$\hbox {D}_2$$ D 2 gas mixture of 96% purity used in KATRIN commissioning runs. The achieved precision on the energy-loss function has abated the corresponding uncertainty of $$\sigma (m_\nu ^2)< {{10}^{-2}}{\hbox {eV}^{2}}$$ σ ( m ν 2 ) < 10 - 2 eV 2 [1] in the KATRIN neutrino-mass measurement to a subdominant level.

Published
2021

10. Bound on 3+1 Active-Sterile Neutrino Mixing from the First Four-Week Science Run of KATRIN

Author

Aker, M, Altenmüller, K, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Blaum, K, Block, F, Bornschein, B, Bornschein, L, Böttcher, M, Brunst, T, Caldwell, TS, La Cascio, L, Chilingaryan, S, Choi, W, Barrero, D Díaz, Debowski, K, Deffert, M, Descher, M, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Fedkevych, M, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gil, W, Glück, F, Grössle, R, Gumbsheimer, R, Höhn, T, Hannen, V, Haußmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Houdy, T, Huber, A, Jansen, A, Köllenberger, L, Karl, C, Kellerer, J, Kippenbrock, L, Klein, M, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, Lasserre, T, Le, TL, Lebeda, O, Le Guennic, N, Lehnert, B, Lokhov, A, Poyato, JM Lopez, Müller, K, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Mertens, S, Niemes, S, Oelpmann, P, Osipowicz, A, Parno, DS, Poon, AWP, Priester, F, Röllig, M, Röttele, C, Rest, O, Robertson, RGH, Rodenbeck, C, Ryšavý, M, Sack, R, Saenz, A, Schaller, A, Schäfer, P, Schimpf, L, Schlösser, M, Schlösser, K, Schlüter, L, Schrank, M, and Schulz, B

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, KATRIN Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

We report on the light sterile neutrino search from the first four-week science run of the KATRIN experiment in 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are analyzed by a high-resolution MAC-E filter down to 40 eV below the endpoint at 18.57 keV. We consider the framework with three active neutrinos and one sterile neutrino. The analysis is sensitive to the mass, m_{4}, of the fourth mass state for m_{4}^{2}≲1000  eV^{2} and to active-to-sterile neutrino mixing down to |U_{e4}|^{2}≳2×10^{-2}. No significant spectral distortion is observed and exclusion bounds on the sterile mass and mixing are reported. These new limits supersede the Mainz results for m_{4}^{2}≲1000  eV^{2} and improve the Troitsk bound for m_{4}^{2}

Published
2021

11. Suppression of Penning discharges between the KATRIN spectrometers

Author

Aker, M, Altenmüller, K, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Blaum, K, Block, F, Bobien, S, Bornschein, B, Bornschein, L, Bouquet, H, Brunst, T, Caldwell, TS, Chilingaryan, S, Choi, W, Debowski, K, Deffert, M, Descher, M, Díaz Barrero, D, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Eversheim, D, Fedkevych, M, Felden, A, Formaggio, JA, Fränkle, F, Franklin, GB, Frankrone, H, Friedel, F, Fulst, A, Gauda, K, Gil, W, Glück, F, Grohmann, S, Grössle, R, Gumbsheimer, R, Hackenjos, M, Hannen, V, Hartmann, J, Haußmann, N, Heizmann, F, Heizmann, J, Helbing, K, Hickford, S, Hillesheimer, D, Hinz, D, Höhn, T, Holzapfel, B, Holzmann, S, Houdy, T, Jansen, A, Karl, C, Kellerer, J, Kernert, N, Kippenbrock, L, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, Kuffner, B, Kunka, N, Lasserre, T, La Cascio, L, Lebeda, O, Lehnert, B, Letnev, J, Leven, F, Le, TL, Lichter, S, Lokhov, A, Machatschek, M, Malcherek, E, Marsteller, A, Martin, EL, Melzer, C, Menshikov, A, Mertens, S, Mirz, S, Monreal, B, Müller, K, Naumann, U, Neumann, H, Niemes, S, Noe, M, Ortjohann, HW, Osipowicz, A, Otten, E, Parno, DS, and Pollithy, A

Subjects
Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to determine the effective electron (anti)-neutrino mass with a sensitivity of 0.2eV/c2 by precisely measuring the endpoint region of the tritium β-decay spectrum. It uses a tandem of electrostatic spectrometers working as magnetic adiabatic collimation combined with an electrostatic (MAC-E) filters. In the space between the pre-spectrometer and the main spectrometer, creating a Penning trap is unavoidable when the superconducting magnet between the two spectrometers, biased at their respective nominal potentials, is energized. The electrons accumulated in this trap can lead to discharges, which create additional background electrons and endanger the spectrometer and detector section downstream. To counteract this problem, “electron catchers” were installed in the beamline inside the magnet bore between the two spectrometers. These catchers can be moved across the magnetic-flux tube and intercept on a sub-ms time scale the stored electrons along their magnetron motion paths. In this paper, we report on the design and the successful commissioning of the electron catchers and present results on their efficiency in reducing the experimental background.

Published
2020

12. Quantitative Long-Term Monitoring of the Circulating Gases in the KATRIN Experiment Using Raman Spectroscopy.

Author

Aker, Max, Altenmüller, Konrad, Beglarian, Armen, Behrens, Jan, Berlev, Anatoly, Besserer, Uwe, Bieringer, Benedikt, Blaum, Klaus, Block, Fabian, Bornschein, Beate, Bornschein, Lutz, Böttcher, Matthias, Brunst, Tim, Caldwell, Thomas C, Chilingaryan, Suren, Choi, Wonqook, Díaz Barrero, Deseada D, Debowski, Karol, Deffert, Marco, Descher, Martin, Doe, Peter J, Dragoun, Otokar, Drexlin, Guido, Dyba, Stephan, Edzards, Frank, Eitel, Klaus, Ellinger, Enrico, Engel, Ralph, Enomoto, Sanshiro, Fedkevych, Mariia, Felden, Arne, Formaggio, Joseph F, Fränkle, Florian, Franklin, Gregg B, Friedel, Fabian, Fulst, Alexander, Gauda, Kevin, Gil, Woosik, Glück, Ferenc, Größle, Robin, Gumbsheimer, Rainer, Hannen, Volker, Haußmann, Norman, Helbing, Klaus, Hickford, Stephanie, Hiller, Roman, Hillesheimer, David, Hinz, Dominic, Höhn, Thomas, Houdy, Thibaut, Huber, Anton, Jansen, Alexander, Karl, Christian, Kellerer, Jonas, Kippenbrock, Luke, Klein, Manuel, Köhler, Christoph, Köllenberger, Leonard, Kopmann, Andreas, Korzeczek, Marc, Kovalík, Alojz, Krasch, Bennet, Krause, Holger, La Cascio, Luisa, Lasserre, Thierry, Le, Thanh-Long, Lebeda, Ondřej, Lehnert, Bjoern, Lokhov, Alexey, Machatschek, Moritz, Malcherek, Emma, Marsteller, Alexander, Martin, Eric L, Meier, Matthias, Melzer, Christin, Mertens, Susanne, Müller, Klaus, Niemes, Simon, Oelpmann, Patrick, Osipowicz, Alexander, Parno, Diana S, Poon, Alan WP, Lopez Poyato, Jose M, Priester, Florian, Rest, Oliver, Röllig, Marco, Röttele, Carsten, Robertson, RG Hamish, Rodenbeck, Caroline, Ryšavỳ, Milos, Sack, Rudolf, Saenz, Alejandro, Schäfer, Peter, Schaller Née Pollithy, Anna, Schimpf, Lutz, Schlösser, Klaus, Schlösser, Magnus, Schlüter, Lisa, Schrank, Michael, and Schulz, Bruno

Subjects
KATRIN, Raman spectroscopy, gas composition monitoring, tritium, Analytical Chemistry, Distributed Computing, Electrical and Electronic Engineering, Environmental Science and Management, Ecology
Abstract

The Karlsruhe Tritium Neutrino (KATRIN) experiment aims at measuring the effective electron neutrino mass with a sensitivity of 0.2 eV/c2, i.e., improving on previous measurements by an order of magnitude. Neutrino mass data taking with KATRIN commenced in early 2019, and after only a few weeks of data recording, analysis of these data showed the success of KATRIN, improving on the known neutrino mass limit by a factor of about two. This success very much could be ascribed to the fact that most of the system components met, or even surpassed, the required specifications during long-term operation. Here, we report on the performance of the laser Raman (LARA) monitoring system which provides continuous high-precision information on the gas composition injected into the experiment's windowless gaseous tritium source (WGTS), specifically on its isotopic purity of tritium-one of the key parameters required in the derivation of the electron neutrino mass. The concentrations cx for all six hydrogen isotopologues were monitored simultaneously, with a measurement precision for individual components of the order 10-3 or better throughout the complete KATRIN data taking campaigns to date. From these, the tritium purity, εT, is derived with precision of

Published
2020

13. High-resolution spectroscopy of gaseous 83mKr conversion electrons with the KATRIN experiment

Author

Altenmüller, K, Arenz, M, Baek, WJ, Beck, M, Beglarian, A, Behrens, J, Bergmann, T, Berlev, A, Besserer, U, Blaum, K, Block, F, Bobien, S, Bode, T, Bornschein, B, Bornschein, L, Brunst, T, Buzinsky, N, Chilingaryan, S, Choi, WQ, Deffert, M, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Eversheim, D, Fedkevych, M, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gil, W, Glück, F, Ureña, AG, Grohmann, S, Grössle, R, Gumbsheimer, R, Hackenjos, M, Hannen, V, Harms, F, Haußmann, N, Heizmann, F, Helbing, K, Hickford, S, Hilk, D, Hillesheimer, D, Hinz, D, Howe, MA, Huber, A, Jansen, A, Kellerer, J, Kernert, N, Kippenbrock, L, Klein, M, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Kraus, M, Lasserre, T, Lebeda, O, Letnev, J, Lokhov, A, Machatschek, M, Marsteller, A, Martin, EL, Mertens, S, Mirz, S, Monreal, B, Neumann, H, Niemes, S, Off, A, Osipowicz, A, Otten, E, Parno, DS, Plischke, P, Pollithy, A, Poon, AWP, Priester, F, C-O Ranitzsch, P, Rest, O, Robertson, RGH, Roccati, F, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Schimpf, L, Schlösser, K, Schlösser, M, Schönung, K, Schrank, M, and Seitz-Moskaliuk, H

Subjects
Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

In this work, we present the first spectroscopic measurements of conversion electrons originating from the decay of metastable gaseous 83mKr with the Karlsruhe Tritium Neutrino (KATRIN) experiment. The obtained results represent one of the major commissioning milestones for the subsequent direct neutrino mass measurement with KATRIN. The successful campaign demonstrates the functionalities of the KATRIN beamline. Precise measurement of the narrow K-32, L3-32, and N2,3-32 conversion electron lines allowed to verify the eV-scale energy resolution of the KATRIN main spectrometer necessary for competitive measurement of the absolute neutrino mass scale.

Published
2020

14. First operation of the KATRIN experiment with tritium

Author

Aker, M, Altenmüller, K, Arenz, M, Baek, WJ, Barrett, J, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Blaum, K, Block, F, Bobien, S, Bornschein, B, Bornschein, L, Bouquet, H, Brunst, T, Caldwell, TS, Chilingaryan, S, Choi, W, Debowski, K, Deffert, M, Descher, M, Díaz Barrero, D, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Eversheim, D, Fedkevych, M, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Frankrone, H, Friedel, F, Fuchs, D, Fulst, A, Gauda, K, Gil, W, Glück, F, Grohmann, S, Grössle, R, Gumbsheimer, R, Hackenjos, M, Hannen, V, Hartmann, J, Haußmann, N, Ha-Minh, M, Heizmann, F, Heizmann, J, Helbing, K, Hickford, S, Hillesheimer, D, Hinz, D, Höhn, T, Holzapfel, B, Holzmann, S, Houdy, T, Howe, MA, Huber, A, Jansen, A, Karl, C, Kellerer, J, Kernert, N, Kippenbrock, L, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, Kuffner, B, Kunka, N, Lasserre, T, La Cascio, L, Lebeda, O, Lebert, M, Lehnert, B, Letnev, J, Leven, F, Le, TL, Lichter, S, Lokhov, A, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Megas, F, Melzer, C, Menshikov, A, Mertens, S, and Meier, M

Subjects
Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

The determination of the neutrino mass is one of the major challenges in astroparticle physics today. Direct neutrino mass experiments, based solely on the kinematics of β -decay, provide a largely model-independent probe to the neutrino mass scale. The Karlsruhe Tritium Neutrino (KATRIN) experiment is designed to directly measure the effective electron antineutrino mass with a sensitivity of 0.2eV (90 % CL). In this work we report on the first operation of KATRIN with tritium which took place in 2018. During this commissioning phase of the tritium circulation system, excellent agreement of the theoretical prediction with the recorded spectra was found and stable conditions over a time period of 13 days could be established. These results are an essential prerequisite for the subsequent neutrino mass measurements with KATRIN in 2019.

Published
2020

15. Gamma-induced background in the KATRIN main spectrometer

Author

Altenmüller, K, Arenz, M, Baek, WJ, Beck, M, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Blaum, K, Block, F, Bobien, S, Bode, T, Bornschein, B, Bornschein, L, Bouquet, H, Brunst, T, Buzinsky, N, Chilingaryan, S, Choi, WQ, Deffert, M, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Erhard, M, Eversheim, D, Fedkevych, M, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gil, W, Glück, F, Ureña, AG, Grössle, R, Gumbsheimer, R, Hackenjos, M, Hannen, V, Harms, F, Haußmann, N, Heizmann, F, Helbing, K, Herz, W, Hickford, S, Hilk, D, Hillesheimer, D, Howe, MA, Huber, A, Jansen, A, Karl, C, Kellerer, J, Kernert, N, Kippenbrock, L, Klein, M, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Kraus, A, Kraus, M, Lasserre, T, Lebeda, O, Lehnert, B, Letnev, J, Lokhov, A, Machatschek, M, Marsteller, A, Martin, EL, Mertens, S, Mirz, S, Monreal, B, Neumann, H, Niemes, S, Osipowicz, A, Otten, E, Parno, DS, Pollithy, A, Poon, AWP, Priester, F, Ranitzsch, PCO, Rest, O, Robertson, RGH, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Schimpf, L, Schlösser, K, Schlösser, M, Schlüter, L, Schrank, M, Seitz-Moskaliuk, H, and Sibille, V

Subjects
Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

The KATRIN experiment aims to measure the effective electron antineutrino mass mν¯e with a sensitivity of 0.2eV/c2 using a gaseous tritium source combined with the MAC-E filter technique. A low background rate is crucial to achieving the proposed sensitivity, and dedicated measurements have been performed to study possible sources of background electrons. In this work, we test the hypothesis that gamma radiation from external radioactive sources significantly increases the rate of background events created in the main spectrometer (MS) and observed in the focal-plane detector. Using detailed simulations of the gamma flux in the experimental hall, combined with a series of experimental tests that artificially increased or decreased the local gamma flux to the MS, we set an upper limit of 0.006count/s (90% C.L.) from this mechanism. Our results indicate the effectiveness of the electrostatic and magnetic shielding used to block secondary electrons emitted from the inner surface of the MS.

Published
2019

16. Muon-induced background in the KATRIN main spectrometer

Author

Altenmüller, K, Arenz, M, Baek, W-J, Beck, M, Beglarian, A, Behrens, J, Bergmann, T, Berlev, A, Besserer, U, Blaum, K, Bobien, S, Bode, T, Bornschein, B, Bornschein, L, Brunst, T, Buzinsky, N, Chilingaryan, S, Choi, WQ, Deffert, M, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Erhard, M, Eversheim, D, Fedkevych, M, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gil, W, Glück, F, Ureña, A Gonzalez, Grohmann, S, Grössle, R, Gumbsheimer, R, Hackenjos, M, Hannen, V, Harms, F, Haußmann, N, Heizmann, F, Helbing, K, Herz, W, Hickford, S, Hilk, D, Hillesheimer, D, Howe, MA, Huber, A, Jansen, A, Kellerer, J, Kernert, N, Kippenbrock, L, Kleesiek, M, Klein, M, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Kraus, M, Kuckert, L, Lasserre, T, Lebeda, O, Leiber, B, Letnev, J, Linek, J, Lokhov, A, Machatschek, M, Marsteller, A, Martin, EL, Mertens, S, Mirz, S, Monreal, B, Neumann, H, Niemes, S, Off, A, Osipowicz, A, Otten, E, Parno, DS, Pollithy, A, Poon, AWP, Priester, F, Ranitzsch, PC-O, Rest, O, Rink, R, Robertson, RGH, Roccati, F, Rodenbeck, C, Röllig, M, Röttele, C, Rovedo, P, Ryšavý, M, Sack, R, Saenz, A, and Schimpf, L

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Cosmic-ray muon backgrounds, Electrostatic spectrometer, Neutrino mass, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Astronomical sciences, Particle and high energy physics
Abstract

The KArlsruhe TRItium Neutrino (KATRIN) experiment aims to make a model-independent determination of the effective electron antineutrino mass with a sensitivity of 0.2 eV/c 2 . It investigates the kinematics of β-particles from tritium β-decay close to the endpoint of the energy spectrum. Because the KATRIN main spectrometer (MS) is located above ground, muon-induced backgrounds are of particular concern. Coincidence measurements with the MS and a scintillator-based muon detector system confirmed the model of secondary electron production by cosmic-ray muons inside the MS. Correlation measurements with the same setup showed that about 12% of secondary electrons emitted from the inner surface are induced by cosmic-ray muons, with approximately one secondary electron produced for every 17 muon crossings. However, the magnetic and electrostatic shielding of the MS is able to efficiently suppress these electrons, and we find that muons are responsible for less than 17% (90% confidence level) of the overall MS background.

Published
2019

17. Reduction of stored-particle background by a magnetic pulse method at the KATRIN experiment

Author

Arenz, M, Baek, W-J, Bauer, S, Beck, M, Beglarian, A, Behrens, J, Berendes, R, Bergmann, T, Berlev, A, Besserer, U, Blaum, K, Bode, T, Bornschein, B, Bornschein, L, Brunst, T, Buglak, W, Buzinsky, N, Chilingaryan, S, Choi, WQ, Deffert, M, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Erhard, M, Eversheim, D, Fedkevych, M, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Furse, D, Gil, W, Glück, F, Ureña, A Gonzalez, Grohmann, S, Grössle, R, Gumbsheimer, R, Hackenjos, M, Hannen, V, Harms, F, Haußmann, N, Heizmann, F, Helbing, K, Herz, W, Hickford, S, Hilk, D, Howe, MA, Huber, A, Jansen, A, Kellerer, J, Kernert, N, Kippenbrock, L, Kleesiek, M, Klein, M, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Kraus, M, Kuckert, L, Lasserre, T, Lebeda, O, Letnev, J, Lokhov, A, Machatschek, M, Marsteller, A, Martin, EL, Mertens, S, Mirz, S, Monreal, B, Neumann, H, Niemes, S, Off, A, Osipowicz, A, Otten, E, Parno, DS, Pollithy, A, Poon, AWP, Priester, F, Ranitzsch, PC-O, Rest, O, Robertson, RGH, Roccati, F, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Schimpf, L, Schlösser, K, Schlösser, M, and Schönung, K

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, physics.ins-det, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

The KATRIN experiment aims to determine the effective electron neutrino mass with a sensitivity of 0.2eV/c2 (%90 CL) by precision measurement of the shape of the tritium β -spectrum in the endpoint region. The energy analysis of the decay electrons is achieved by a MAC-E filter spectrometer. A common background source in this setup is the decay of short-lived isotopes, such as 219Rn and 220Rn , in the spectrometer volume. Active and passive countermeasures have been implemented and tested at the KATRIN main spectrometer. One of these is the magnetic pulse method, which employs the existing air coil system to reduce the magnetic guiding field in the spectrometer on a short timescale in order to remove low- and high-energy stored electrons. Here we describe the working principle of this method and present results from commissioning measurements at the main spectrometer. Simulations with the particle-tracking software Kassiopeia were carried out to gain a detailed understanding of the electron storage conditions and removal processes.

Published
2018

18. The KATRIN superconducting magnets: Overview and first performance results

Author

Arenz, M, Baek, WJ, Beck, M, Beglarian, A, Behrens, J, Bergmann, T, Berlev, A, Besserer, U, Blaum, K, Bode, T, Bornschein, B, Bornschein, L, Brunst, T, Buzinsky, N, Chilingaryan, S, Choi, WQ, Deffert, M, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Erhard, M, Eversheim, D, Fedkevych, M, Formaggio, JA, Frankle, FM, Franklin, GB, Friedel, F, Fulst, A, Gil, W, Glück, F, Urena, AG, Grohmann, S, Grössle, R, Gumbsheimer, R, Hackenjos, M, Hannen, V, Harms, F, Haußmann, N, Heizmann, F, Helbing, K, Herz, W, Hickford, S, Hilk, D, Howe, MA, Huber, A, Jansen, A, Kellerer, J, Kernert, N, Kippenbrock, L, Kleesiek, M, Klein, M, Kopmann, A, Korzeczek, M, Kovalik, A, Krasch, B, Kraus, M, Kuckert, L, Lasserre, T, Lebeda, O, Letnev, J, Lokhov, A, Machatschek, M, Marsteller, A, Martin, EL, Mertens, S, Mirz, S, Monreal, B, Neumann, H, Niemes, S, Off, A, Osipowicz, A, Otten, E, Parno, DS, Pollithy, A, Poon, AWP, Priester, F, Ranitzsch, PCO, Rest, O, Robertson, RGH, Roccati, F, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Schimpf, L, Schlösser, K, Schlösser, M, Schönung, K, Schrank, M, Seitz-Moskaliuk, H, Sentkerestiová, J, and Sibille, V

Subjects
Acceleration cavities and magnets superconducting, Control systems, Cryogenics, Spectrometers, Nuclear & Particles Physics, Other Physical Sciences, Physical Sciences, Engineering
Abstract

The KATRIN experiment aims for the determination of the effective electron anti-neutrino mass from the tritium beta-decay with an unprecedented sub-eV sensitivity. The strong magnetic fields, designed for up to 6 T, adiabatically guide β-electrons from the source to the detector within a magnetic flux of 191 Tcm2. A chain of ten single solenoid magnets and two larger superconducting magnet systems have been designed, constructed, and installed in the 70-m-long KATRIN beam line. The beam diameter for the magnetic flux varies from 0.064 m to 9 m, depending on the magnetic flux density along the beam line. Two transport and tritium pumping sections are assembled with chicane beam tubes to avoid direct "line-of-sight" molecular beaming effect of gaseous tritium molecules into the next beam sections. The sophisticated beam alignment has been successfully cross-checked by electron sources. In addition, magnet safety systems were developed to protect the complex magnet systems against coil quenches or other system failures. The main functionality of the magnet safety systems has been successfully tested with the two large magnet systems. The complete chain of the magnets was operated for several weeks at 70% of the design fields for the first test measurements with radioactive krypton gas. The stability of the magnetic fields of the source magnets has been shown to be better than 0.01% per month at 70% of the design fields. This paper gives an overview of the KATRIN superconducting magnets and reports on the first performance results of the magnets.

Published
2018

19. Calibration of high voltages at the ppm level by the difference of 83mKr conversion electron lines at the KATRIN experiment

Author

Arenz, M, Baek, W-J, Beck, M, Beglarian, A, Behrens, J, Bergmann, T, Berlev, A, Besserer, U, Blaum, K, Bode, T, Bornschein, B, Bornschein, L, Brunst, T, Buzinsky, N, Chilingaryan, S, Choi, WQ, Deffert, M, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Erhard, M, Eversheim, D, Fedkevych, M, Fischer, S, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gil, W, Glück, F, Ureña, A Gonzalez, Grohmann, S, Grössle, R, Gumbsheimer, R, Hackenjos, M, Hannen, V, Harms, F, Haußmann, N, Heizmann, F, Helbing, K, Herz, W, Hickford, S, Hilk, D, Hillesheimer, D, Howe, MA, Huber, A, Jansen, A, Kellerer, J, Kernert, N, Kippenbrock, L, Kleesiek, M, Klein, M, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Kraus, M, Kuckert, L, Lasserre, T, Lebeda, O, Letnev, J, Lokhov, A, Machatschek, M, Marsteller, A, Martin, EL, Mertens, S, Mirz, S, Monreal, B, Neumann, H, Niemes, S, Off, A, Osipowicz, A, Otten, E, Parno, DS, Pollithy, A, Poon, AWP, Priester, F, Ranitzsch, PC-O, Rest, O, Robertson, RGH, Roccati, F, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Schimpf, L, Schlösser, K, Schlösser, M, Schönung, K, Schrank, M, and Seitz-Moskaliuk, H

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

The neutrino mass experiment KATRIN requires a stability of 3 ppm for the retarding potential at − 18.6 kV of the main spectrometer. To monitor the stability, two custom-made ultra-precise high-voltage dividers were developed and built in cooperation with the German national metrology institute Physikalisch-Technische Bundesanstalt (PTB). Until now, regular absolute calibration of the voltage dividers required bringing the equipment to the specialised metrology laboratory. Here we present a new method based on measuring the energy difference of two 83 mKr conversion electron lines with the KATRIN setup, which was demonstrated during KATRIN’s commissioning measurements in July 2017. The measured scale factor M= 1972.449 (10) of the high-voltage divider K35 is in agreement with the last PTB calibration 4 years ago. This result demonstrates the utility of the calibration method, as well as the long-term stability of the voltage divider.

Published
2018

20. Calibration of high voltages at the ppm level by the difference of 83 m Kr conversion electron lines at the KATRIN experiment

Author

Arenz, M, Baek, WJ, Beck, M, Beglarian, A, Behrens, J, Bergmann, T, Berlev, A, Besserer, U, Blaum, K, Bode, T, Bornschein, B, Bornschein, L, Brunst, T, Buzinsky, N, Chilingaryan, S, Choi, WQ, Deffert, M, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Erhard, M, Eversheim, D, Fedkevych, M, Fischer, S, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gil, W, Glück, F, Ureña, AG, Grohmann, S, Grössle, R, Gumbsheimer, R, Hackenjos, M, Hannen, V, Harms, F, Haußmann, N, Heizmann, F, Helbing, K, Herz, W, Hickford, S, Hilk, D, Hillesheimer, D, Howe, MA, Huber, A, Jansen, A, Kellerer, J, Kernert, N, Kippenbrock, L, Kleesiek, M, Klein, M, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Kraus, M, Kuckert, L, Lasserre, T, Lebeda, O, Letnev, J, Lokhov, A, Machatschek, M, Marsteller, A, Martin, EL, Mertens, S, Mirz, S, Monreal, B, Neumann, H, Niemes, S, Off, A, Osipowicz, A, Otten, E, Parno, DS, Pollithy, A, Poon, AWP, Priester, F, Ranitzsch, PCO, Rest, O, Robertson, RGH, Roccati, F, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Schimpf, L, Schlösser, K, Schlösser, M, Schönung, K, Schrank, M, and Seitz-Moskaliuk, H

Subjects
Nuclear & Particles Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

The neutrino mass experiment KATRIN requires a stability of 3 ppm for the retarding potential at − 18.6 kV of the main spectrometer. To monitor the stability, two custom-made ultra-precise high-voltage dividers were developed and built in cooperation with the German national metrology institute Physikalisch-Technische Bundesanstalt (PTB). Until now, regular absolute calibration of the voltage dividers required bringing the equipment to the specialised metrology laboratory. Here we present a new method based on measuring the energy difference of two 83 mKr conversion electron lines with the KATRIN setup, which was demonstrated during KATRIN’s commissioning measurements in July 2017. The measured scale factor M= 1972.449 (10) of the high-voltage divider K35 is in agreement with the last PTB calibration 4 years ago. This result demonstrates the utility of the calibration method, as well as the long-term stability of the voltage divider.

Published
2018

21. First transmission of electrons and ions through the KATRIN beamline

Author

Arenz, M, Baek, WJ, Beck, M, Beglarian, A, Behrens, J, Bergmann, T, Berlev, A, Besserer, U, Blaum, K, Bode, T, Bornschein, B, Bornschein, L, Brunst, T, Buzinsky, N, Chilingaryan, S, Choi, WQ, Deffert, M, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Erhard, M, Eversheim, D, Fedkevych, M, Fischer, S, Formaggio, JA, Frankle, FM, Franklin, GB, Friedel, F, Fulst, A, Gil, W, Glück, F, Urena, AG, Grohmann, S, Grössle, R, Gumbsheimer, R, Hackenjos, M, Hannen, V, Harms, F, Haußmann, N, Heizmann, F, Helbing, K, Herz, W, Hickford, S, Hilk, D, Hillesheimer, D, Howe, MA, Huber, A, Jansen, A, Kellerer, J, Kernert, N, Kippenbrock, L, Kleesiek, M, Klein, M, Kopmann, A, Korzeczek, M, Kovalik, A, Krasch, B, Kraus, M, Kuckert, L, Lasserre, T, Lebeda, O, Letnev, J, Lokhov, A, Machatschek, M, Marsteller, A, Martin, EL, Mertens, S, Mirz, S, Monreal, B, Naumann, U, Neumann, H, Niemes, S, Off, A, Ortjohann, HW, Osipowicz, A, Otten, E, Parno, DS, Pollithy, A, Poon, AWP, Priester, F, Ranitzsch, PCO, Rest, O, Robertson, RGH, Roccati, F, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Schimpf, L, Schlösser, K, Schlösser, M, and Schönung, K

Subjects
Ion sources (positive ions, negative ions, electron cyclotron resonance (ECR), electron beam (EBIS)), Detector control systems, Beam-line instrumentation, Spectrometers, Ion sources (positive ions, negative ions, electron cyclotron resonance, electron beam (EBIS)), Nuclear & Particles Physics, Other Physical Sciences, Physical Sciences, Engineering
Abstract

The Karlsruhe Tritium Neutrino (KATRIN) experiment is a large-scale effort to probe the absolute neutrino mass scale with a sensitivity of 0.2 eV (90% confidence level), via a precise measurement of the endpoint spectrum of tritium β-decay. This work documents several KATRIN commissioning milestones: the complete assembly of the experimental beamline, the successful transmission of electrons from three sources through the beamline to the primary detector, and tests of ion transport and retention. In the First Light commissioning campaign of autumn 2016, photoelectrons were generated at the rear wall and ions were created by a dedicated ion source attached to the rear section; in July 2017, gaseous 83mKr was injected into the KATRIN source section, and a condensed 83mKr source was deployed in the transport section. In this paper we describe the technical details of the apparatus and the configuration for each measurement, and give first results on source and system performance. We have successfully achieved transmission from all four sources, established system stability, and characterized many aspects of the apparatus.

Published
2018

22. Integrated multi-scale data analytics and machine learning for the distribution grid

Author

Stewart, EM, Top, P, Chertkov, M, Deka, D, Backhaus, S, Lokhov, A, Roberts, C, Hendrix, V, Peisert, S, Florita, A, King, TJ, and Reno, MJ

Subjects
Analytics, Machine Learning, Distribution Grid, DER, validation, verification, prediction, incipient failure
Abstract

We consider the field of machine learning and where it is both useful, and not useful, for the distribution grid and buildings interface. While analytics, in general, is a growing field of interest, and often seen as the golden goose in the burgeoning distribution grid industry, its application is often limited by communications infrastructure, or lack of a focused technical application. Overall, the linkage of analytics to purposeful application in the grid space has been limited. In this paper we consider the field of machine learning as a subset of analytical techniques, and discuss its ability and limitations to enable the future distribution grid. To that end, we also consider the potential for mixing distributed and centralized analytics and the pros and cons of these approaches. There is an exponentially expanding volume of measured data being generated on the distribution grid, which, with appropriate application of analytics, may be transformed into intelligible, actionable information that can be provided to the right actors - such as grid and building operators, at the appropriate time to enhance grid or building resilience, efficiency, and operations against various metrics or goals - such as total carbon reduction or other economic benefit to customers. While some basic analysis into these data streams can provide a wealth of information, computational and human boundaries on performing the analysis are becoming significant, with more data and multi-objective concerns. Efficient applications of analysis and the machine learning field are being considered in the loop. This paper describes benefits and limits of present machine-learning applications for use on the grid and presents a series of case studies that illustrate the potential benefits of developing advanced local multi-variate analytics machine-learning-based applications.

Published
2018

23. Integrated Multi-Scale Data Analytics and Machine Learning for the Distribution Grid

Author

Stewart, Emma M, Florita, Anthony, King, Thomas J, Reno, Matthew J, Top, Philip, Chertkov, Michael, Deka, Deepjyoti, Backhaus, Scott, Lokhov, Andrey, Roberts, Ciaran, Hendrix, Val, and Peisert, Sean

Subjects
Analytics, Machine Learning, Distribution Grid, DER, validation, verification, prediction, incipient failure
Abstract

We consider the field of machine learning and where it is both useful, and not useful, for the distribution grid and buildings interface. While analytics, in general, is a growing field of interest, and often seen as the golden goose in the burgeoning distribution grid industry, its application is often limited by communications infrastructure, or lack of a focused technical application. Overall, the linkage of analytics to purposeful application in the grid space has been limited. In this paper we consider the field of machine learning as a subset of analytical techniques, and discuss its ability and limitations to enable the future distribution grid. To that end, we also consider the potential for mixing distributed and centralized analytics and the pros and cons of these approaches. There is an exponentially expanding volume of measured data being generated on the distribution grid, which, with appropriate application of analytics, may be transformed into intelligible, actionable information that can be provided to the right actors - such as grid and building operators, at the appropriate time to enhance grid or building resilience, efficiency, and operations against various metrics or goals - such as total carbon reduction or other economic benefit to customers. While some basic analysis into these data streams can provide a wealth of information, computational and human boundaries on performing the analysis are becoming significant, with more data and multi-objective concerns. Efficient applications of analysis and the machine learning field are being considered in the loop. This paper describes benefits and limits of present machine-learning applications for use on the grid and presents a series of case studies that illustrate the potential benefits of developing advanced local multi-variate analytics machine-learning-based applications.

Published
2017

24. Commissioning of the vacuum system of the KATRIN Main Spectrometer

Author

Arenz, M, Babutzka, M, Bahr, M, Barrett, JP, Bauer, S, Beck, M, Beglarian, A, Behrens, J, Bergmann, T, Besserer, U, Blümer, J, Bodine, LI, Bokeloh, K, Bonn, J, Bornschein, B, Bornschein, L, Büsch, S, Burritt, TH, Chilingaryan, S, Corona, TJ, De Viveiros, L, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Ebenhöch, S, Eitel, K, Ellinger, E, Enomoto, S, Erhard, M, Eversheim, D, Fedkevych, M, Felden, A, Fischer, S, Formaggio, JA, Fränkle, F, Furse, D, Ghilea, M, Gil, W, Glück, F, Ureña, A Gonzalez, Görhardt, S, Groh, S, Grohmann, S, Grössle, R, Gumbsheimer, R, Hackenjos, M, Hannen, V, Harms, F, Haußmann, N, Heizmann, F, Helbing, K, Herz, W, Hickford, S, Hilk, D, Hillen, B, Höhn, T, Holzapfel, B, Hötzel, M, Howe, MA, Huber, A, Jansen, A, Kernert, N, Kippenbrock, L, Kleesiek, M, Klein, M, Kopmann, A, Kosmider, A, Kovalík, A, Krasch, B, Kraus, M, Krause, H, Krause, M, Kuckert, L, Kuffner, B, La Cascio, L, Lebeda, O, Leiber, B, Letnev, J, Lobashev, VM, Lokhov, A, Malcherek, E, Mark, M, Martin, EL, Mertens, S, Mirz, S, Monreal, B, Müller, K, Neuberger, M, Neumann, H, Niemes, S, Noe, M, Oblath, NS, Off, A, Ortjohann, H-W, Osipowicz, A, Otten, E, Parno, DS, Plischke, P, and Poon, AWP

Subjects
Gas systems and purification, Neutrino detectors, Spectrometers, Vacuum-based detectors, physics.ins-det, Physical Sciences, Engineering, Nuclear & Particles Physics
Abstract

The KATRIN experiment will probe the neutrino mass by measuring the β-electron energy spectrum near the endpoint of tritium β-decay. An integral energy analysis will be performed by an electro-static spectrometer (“Main Spectrometer”), an ultra-high vacuum vessel with a length of 23.2 m, a volume of 1240 m3, and a complex inner electrode system with about 120 000 individual parts. The strong magnetic field that guides the β-electrons is provided by super-conducting solenoids at both ends of the spectrometer. Its influence on turbo-molecular pumps and vacuum gauges had to be considered. A system consisting of 6 turbo-molecular pumps and 3 km of non-evaporable getter strips has been deployed and was tested during the commissioning of the spectrometer. In this paper the configuration, the commissioning with bake-out at 300◦C, and the performance of this system are presented in detail. The vacuum system has to maintain a pressure in the 10−11 mbar range. It is demonstrated that the performance of the system is already close to these stringent functional requirements for the KATRIN experiment, which will start at the end of 2016.

Published
2016

25. Integrated Multi-Scale Data Analytics and Machine Learning for the Distribution Grid

Author

Anthony R. Florita, Deepjyoti Deka, Matthew J. Reno, Scott Backhaus, Ciaran Roberts, Sean Peisert, Michael Chertkov, Emma Stewart, Andrey Y. Lokhov, Philip Top, Valerie Hendrix, and Thomas J. King

Subjects
0209 industrial biotechnology, Analytics, Computer science, Interface (computing), 02 engineering and technology, 010501 environmental sciences, Machine learning, computer.software_genre, 01 natural sciences, Field (computer science), Machine Learning, 020901 industrial engineering & automation, Resilience (network), 0105 earth and related environmental sciences, incipient failure, validation, business.industry, Data stream mining, Distribution Grid, prediction, Grid, DER, Smart grid, Data analysis, Artificial intelligence, business, verification, computer
Abstract

We consider the field of machine learning and where it is both useful, and not useful, for the distribution grid and buildings interface. While analytics, in general, is a growing field of interest, and often seen as the golden goose in the burgeoning distribution grid industry, its application is often limited by communications infrastructure, or lack of a focused technical application. Overall, the linkage of analytics to purposeful application in the grid space has been limited. In this paper we consider the field of machine learning as a subset of analytical techniques, and discuss its ability and limitations to enable the future distribution grid. To that end, we also consider the potential for mixing distributed and centralized analytics and the pros and cons of these approaches. There is an exponentially expanding volume of measured data being generated on the distribution grid, which, with appropriate application of analytics, may be transformed into intelligible, actionable information that can be provided to the right actors - such as grid and building operators, at the appropriate time to enhance grid or building resilience, efficiency, and operations against various metrics or goals - such as total carbon reduction or other economic benefit to customers. While some basic analysis into these data streams can provide a wealth of information, computational and human boundaries on performing the analysis are becoming significant, with more data and multi-objective concerns. Efficient applications of analysis and the machine learning field are being considered in the loop. This paper describes benefits and limits of present machine-learning applications for use on the grid and presents a series of case studies that illustrate the potential benefits of developing advanced local multi-variate analytics machine-learning-based applications.

Published
2017

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