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KATRIN Sensitivity to keV Sterile Neutrinos with the TRISTAN Detector Upgrade
Authors:
H. Acharya,
M. Aker,
D. Batzler,
A. Beglarian,
J. Beisenkötter,
M. Biassoni,
B. Bieringer,
Y. Biondi,
B. Bornschein,
L. Bornschein,
M. Böttcher,
M. Carminati,
A. Chatrabhuti,
S. Chilingaryan,
B. A. Daniel,
M. Descher,
D. Díaz Barrero,
P. J. Doe,
O. Dragoun,
G. Drexlin,
E. Ellinger,
R. Engel,
K. Erhardt,
L. Fallböhmer,
A. Felden
, et al. (105 additional authors not shown)
Abstract:
Sterile neutrinos in the keV mass range are a well-motivated extension of the Standard Model and viable dark matter candidates. Their existence can be probed in laboratory experiments, as the admixture of a sterile state would induce a characteristic kink-like distortion in the $β$-decay electron energy spectrum. The KATRIN experiment is designed to measure the effective electron neutrino mass wit…
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Sterile neutrinos in the keV mass range are a well-motivated extension of the Standard Model and viable dark matter candidates. Their existence can be probed in laboratory experiments, as the admixture of a sterile state would induce a characteristic kink-like distortion in the $β$-decay electron energy spectrum. The KATRIN experiment is designed to measure the effective electron neutrino mass with sub-eV sensitivity by analyzing the endpoint region of the tritium $β$-decay spectrum. Following the completion of its neutrino mass program, KATRIN will extend its physics reach to the search for keV-scale sterile neutrinos. This effort will be enabled by the TRISTAN detector, a newly developed silicon drift detector array optimized for differential measurements at high rates and energies well below the endpoint. In this article, we present the projected sensitivity of KATRIN to keV-scale sterile neutrinos using a dedicated simulation framework. With four months of detector livetime, KATRIN has the statistical power to probe mixing amplitudes at the level of $|U_{e4}|^2 \sim 10^{-6}$ for sterile neutrino masses in the (4$-$13) keV range, significantly extending the reach of previous laboratory searches. The major experimental systematic uncertainties investigated in this work reduces the sensitivity by a factor of 10$-$50 over the same mass range.
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Submitted 15 April, 2026; v1 submitted 24 March, 2026;
originally announced March 2026.
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Measurement of the inhomogeneity of the KATRIN tritium source electric potential by high-resolution spectroscopy of conversion electrons from $^{83m}$Kr
Authors:
H. Acharya,
M. Aker,
D. Batzler,
A. Beglarian,
J. Beisenkötter,
M. Biassoni,
B. Bieringer,
Y. Biondi,
F. Block,
B. Bornschein,
L. Bornschein,
M. Böttcher,
M. Carminati,
A. Chatrabhuti,
S. Chilingaryan,
B. A. Daniel,
M. Descher,
D. Díaz Barrero,
O. Dragoun,
G. Drexlin,
F. Edzards,
K. Eitel,
E. Ellinger,
R. Engel,
S. Enomoto
, et al. (108 additional authors not shown)
Abstract:
Precision spectroscopy of the electron spectrum of the tritium $β$-decay near the kinematic endpoint is a direct method to determine the effective electron antineutrino mass. The KArlsruhe TRItium Neutrino (KATRIN) experiment aims to determine this quantity with a sensitivity of better than 0.3$\,$eV (90$\,$% C.L.). An inhomogeneous electric potential in the tritium source of KATRIN can lead to di…
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Precision spectroscopy of the electron spectrum of the tritium $β$-decay near the kinematic endpoint is a direct method to determine the effective electron antineutrino mass. The KArlsruhe TRItium Neutrino (KATRIN) experiment aims to determine this quantity with a sensitivity of better than 0.3$\,$eV (90$\,$% C.L.). An inhomogeneous electric potential in the tritium source of KATRIN can lead to distortions of the $β$-spectrum, which directly impact the neutrino-mass observable. This effect can be quantified through precision spectroscopy of the conversion-electrons of co-circulated metastable $^{83m}$Kr. Therefore, dedicated, several-weeks long measurement campaigns have been performed within the KATRIN data taking schedule. In this work, we infer the tritium source potential observables from these measurements, and present their implications for the neutrino-mass determination.
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Submitted 17 March, 2025;
originally announced March 2025.
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First constraints on general neutrino interactions based on KATRIN data
Authors:
M. Aker,
D. Batzler,
A. Beglarian,
J. Beisenkötter,
M. Biassoni,
B. Bieringer,
Y. Biondi,
F. Block,
B. Bornschein,
L. Bornschein,
M. Böttcher,
M. Carminati,
A. Chatrabhuti,
S. Chilingaryan,
B. A. Daniel,
M. Descher,
D. Díaz Barrero,
P. J. Doe,
O. Dragoun,
G. Drexlin,
F. Edzards,
K. Eitel,
E. Ellinger,
R. Engel,
S. Enomoto
, et al. (108 additional authors not shown)
Abstract:
The precision measurement of the tritium $β$-decay spectrum performed by the KATRIN experiment provides a unique way to search for general neutrino interactions (GNI). All theoretical allowed GNI terms involving neutrinos are incorporated into a low-energy effective field theory, and can be identified by specific signatures in the measured tritium $β$-spectrum. In this paper an effective descripti…
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The precision measurement of the tritium $β$-decay spectrum performed by the KATRIN experiment provides a unique way to search for general neutrino interactions (GNI). All theoretical allowed GNI terms involving neutrinos are incorporated into a low-energy effective field theory, and can be identified by specific signatures in the measured tritium $β$-spectrum. In this paper an effective description of the impact of GNI on the $β$-spectrum is formulated and the first constraints on the effective GNI parameters are derived based on the 4 million electrons collected in the second measurement campaign of KATRIN in 2019. In addition, constraints on selected types of interactions are investigated, thereby exploring the potential of KATRIN to search for more specific new physics cases, including a right-handed W boson, a charged Higgs or leptoquarks.
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Submitted 12 November, 2024; v1 submitted 14 October, 2024;
originally announced October 2024.
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Direct neutrino-mass measurement based on 259 days of KATRIN data
Authors:
M. Aker,
D. Batzler,
A. Beglarian,
J. Behrens,
J. Beisenkötter,
M. Biassoni,
B. Bieringer,
Y. Biondi,
F. Block,
S. Bobien,
M. Böttcher,
B. Bornschein,
L. Bornschein,
T. S. Caldwell,
M. Carminati,
A. Chatrabhuti,
S. Chilingaryan,
B. A. Daniel,
K. Debowski,
M. Descher,
D. Díaz Barrero,
P. J. Doe,
O. Dragoun,
G. Drexlin,
F. Edzards
, et al. (124 additional authors not shown)
Abstract:
The fact that neutrinos carry a non-vanishing rest mass is evidence of physics beyond the Standard Model of elementary particles. Their absolute mass bears important relevance from particle physics to cosmology. In this work, we report on the search for the effective electron antineutrino mass with the KATRIN experiment. KATRIN performs precision spectroscopy of the tritium $β$-decay close to the…
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The fact that neutrinos carry a non-vanishing rest mass is evidence of physics beyond the Standard Model of elementary particles. Their absolute mass bears important relevance from particle physics to cosmology. In this work, we report on the search for the effective electron antineutrino mass with the KATRIN experiment. KATRIN performs precision spectroscopy of the tritium $β$-decay close to the kinematic endpoint. Based on the first five neutrino-mass measurement campaigns, we derive a best-fit value of $m_ν^{2} = {-0.14^{+0.13}_{-0.15}}~\mathrm{eV^2}$, resulting in an upper limit of $m_ν< {0.45}~\mathrm{eV}$ at 90 % confidence level. With six times the statistics of previous data sets, amounting to 36 million electrons collected in 259 measurement days, a substantial reduction of the background level and improved systematic uncertainties, this result tightens KATRIN's previous bound by a factor of almost two.
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Submitted 19 June, 2024;
originally announced June 2024.
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Search for keV-scale Sterile Neutrinos with first KATRIN Data
Authors:
M. Aker,
D. Batzler,
A. Beglarian,
J. Behrens,
A. Berlev,
U. Besserer,
B. Bieringer,
F. Block,
S. Bobien,
B. Bornschein,
L. Bornschein,
M. Böttcher,
T. Brunst,
T. S. Caldwell,
R. M. D. Carney,
S. Chilingaryan,
W. Choi,
K. Debowski,
M. Descher,
D. Díaz Barrero,
P. J. Doe,
O. Dragoun,
G. Drexlin,
F. Edzards,
K. Eitel
, et al. (106 additional authors not shown)
Abstract:
In this work we present a keV-scale sterile-neutrino search with the first tritium data of the KATRIN experiment, acquired in the 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 search…
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In this work we present a keV-scale sterile-neutrino search with the first tritium data of the KATRIN experiment, acquired in the 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 search for sterile neutrinos with a mass of up to $1.6\, \mathrm{keV}$. We do not find a signal and set an exclusion limit on the sterile-to-active mixing amplitude of down to $\sin^2θ< 5\cdot10^{-4}$ ($95\,\%$ C.L.), improving current laboratory-based bounds in the sterile-neutrino mass range between 0.1 and $1.0\, \mathrm{keV}$.
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Submitted 13 July, 2022;
originally announced July 2022.
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Search for Lorentz-Invariance Violation with the first KATRIN data
Authors:
M. Aker,
D. Batzler,
A. Beglarian,
J. Behrens,
A. Berlev,
U. Besserer,
B. Bieringer,
F. Block,
S. Bobien,
B. Bornschein,
L. Bornschein,
M. Böttcher,
T. Brunst,
T. S. Caldwell,
R. M. D. Carney,
S. Chilingaryan,
W. Choi,
K. Debowski,
M. Deffert,
M. Descher,
D. Díaz Barrero,
P. J. Doe,
O. Dragoun,
G. Drexlin,
F. Edzards
, et al. (108 additional authors not shown)
Abstract:
Some extensions of the Standard Model of Particle Physics allow for Lorentz invariance and Charge-Parity-Time (CPT)-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…
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Some extensions of the Standard Model of Particle Physics allow for Lorentz invariance and Charge-Parity-Time (CPT)-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 $(a_{\text{of}}^{(3)})_{00}$, $(a_{\text{of}}^{(3)})_{10}$ and $(a_{\text{of}}^{(3)})_{11}$ which would manifest themselves in a non-isotropic beta-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 limit on $\left|(a_{\text{of}}^{(3)})_{11}\right|$ of $< 3.7\cdot10^{-6}$ GeV at 90\% confidence level. Moreover, we derive new constraints on $(a_{\text{of}}^{(3)})_{00}$ and $(a_{\text{of}}^{(3)})_{10}$.
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Submitted 13 July, 2022;
originally announced July 2022.
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KATRIN: Status and Prospects for the Neutrino Mass and Beyond
Authors:
M. Aker,
M. Balzer,
D. Batzler,
A. Beglarian,
J. Behrens,
A. Berlev,
U. Besserer,
M. Biassoni,
B. Bieringer,
F. Block,
S. Bobien,
L. Bombelli,
D. Bormann,
B. Bornschein,
L. Bornschein,
M. Böttcher,
C. Brofferio,
C. Bruch,
T. Brunst,
T. S. Caldwell,
M. Carminati,
R. M. D. Carney,
S. Chilingaryan,
W. Choi,
O. Cremonesi
, et al. (137 additional authors not shown)
Abstract:
The Karlsruhe Tritium Neutrino (KATRIN) experiment is designed to measure a high-precision integral spectrum of the endpoint region of T2 beta 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 su…
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The Karlsruhe Tritium Neutrino (KATRIN) experiment is designed to measure a high-precision integral spectrum of the endpoint region of T2 beta 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.
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Submitted 16 June, 2023; v1 submitted 15 March, 2022;
originally announced March 2022.
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New Constraint on the Local Relic Neutrino Background Overdensity with the First KATRIN Data Runs
Authors:
M. Aker,
D. Batzler,
A. Beglarian,
J. Behrens,
A. Berlev,
U. Besserer,
B. Bieringer,
F. Block,
S. Bobien,
B. Bornschein,
L. Bornschein,
M. Böttcher,
T. Brunst,
T. S. Caldwell,
R. M. D. Carney,
S. Chilingaryan,
W. Choi,
K. Debowski,
M. Descher,
D. Díaz Barrero,
P. J. Doe,
O. Dragoun,
G. Drexlin,
F. Edzards,
K. Eitel
, et al. (107 additional authors not shown)
Abstract:
We report on the direct cosmic relic neutrino background search from the first two science runs 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 kinematic endpoint at 18.57 keV. The analysis is sensitive to a local relic neutrino overdensity of 9.7e10 (1.1e11) at a 90% (95%) confidence l…
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We report on the direct cosmic relic neutrino background search from the first two science runs 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 kinematic endpoint at 18.57 keV. The analysis is sensitive to a local relic neutrino overdensity of 9.7e10 (1.1e11) at a 90% (95%) confidence level. A fit of the integrated electron spectrum over a narrow interval around the kinematic endpoint accounting for relic neutrino captures in the Tritium source reveals no significant overdensity. This work improves the results obtained by the previous kinematic neutrino mass experiments at Los Alamos and Troitsk. We furthermore update the projected final sensitivity of the KATRIN experiment to <1e10 at 90% confidence level, by relying on updated operational conditions.
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Submitted 9 February, 2022;
originally announced February 2022.
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First direct neutrino-mass measurement with sub-eV sensitivity
Authors:
M. Aker,
A. Beglarian,
J. Behrens,
A. Berlev,
U. Besserer,
B. Bieringer,
F. Block,
B. Bornschein,
L. Bornschein,
M. Böttcher,
T. Brunst,
T. S. Caldwell,
R. M. D. Carney,
L. La Cascio,
S. Chilingaryan,
W. Choi,
K. Debowski,
M. Deffert,
M. Descher,
D. Díaz Barrero,
P. J. Doe,
O. Dragoun,
G. Drexlin,
K. Eitel,
E. Ellinger
, et al. (103 additional authors not shown)
Abstract:
We report the results of the second measurement campaign of the Karlsruhe Tritium Neutrino (KATRIN) experiment. KATRIN probes the effective electron anti-neutrino mass, $m_ν$, via a high-precision measurement of the tritium $β$-decay spectrum close to its endpoint at $18.6\,\mathrm{keV}$. In the second physics run presented here, the source activity was increased by a factor of 3.8 and the backgro…
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We report the results of the second measurement campaign of the Karlsruhe Tritium Neutrino (KATRIN) experiment. KATRIN probes the effective electron anti-neutrino mass, $m_ν$, via a high-precision measurement of the tritium $β$-decay spectrum close to its endpoint at $18.6\,\mathrm{keV}$. In the second physics run presented here, the source activity was increased by a factor of 3.8 and the background was reduced by $25\,\%$ with respect to the first campaign. A sensitivity on $m_ν$ of $0.7\,\mathrm{eV/c^2}$ at $90\,\%$ confidence level (CL) was reached. This is the first sub-eV sensitivity from a direct neutrino-mass experiment. The best fit to the spectral data yields $m_ν^2 = (0.26\pm0.34)\,\mathrm{eV^4/c^4}$, resulting in an upper limit of $m_ν<0.9\,\mathrm{eV/c^2}$ ($90\,\%$ CL). By combining this result with the first neutrino mass campaign, we find an upper limit of $m_ν<0.8\,\mathrm{eV/c^2}$ ($90\,\%$ CL).
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Submitted 18 May, 2021;
originally announced May 2021.
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Analysis methods for the first KATRIN neutrino-mass measurement
Authors:
M. Aker,
K. Altenmüller,
A. Beglarian,
J. Behrens,
A. Berlev,
U. Besserer,
B. Bieringer,
K. Blaum,
F. Block,
B. Bornschein,
L. Bornschein,
M. Böttcher,
T. Brunst,
T. S. Caldwell,
L. La Cascio,
S. Chilingaryan,
W. Choi,
D. Díaz Barrero,
K. Debowski,
M. Deffert,
M. Descher,
P. J. Doe,
O. Dragoun,
G. Drexlin,
S. Dyba
, et al. (104 additional authors not shown)
Abstract:
We report on the data set, 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 T$_2$ gas. The $β$ electrons are guided along magnetic field lines toward a high-resolution, inte…
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We report on the data set, 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 T$_2$ 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.
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Submitted 12 May, 2021; v1 submitted 13 January, 2021;
originally announced January 2021.
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Bound on 3+1 active-sterile neutrino mixing from the first four-week science run of KATRIN
Authors:
M. Aker,
K. Altenmueller,
A. Beglarian,
J. Behrens,
A. Berlev,
U. Besserer,
B. Bieringer,
K. Blaum,
F. Block,
B. Bornschein,
L. Bornschein,
M. Boettcher,
T. Brunst,
T. S. Caldwell,
L. La Cascio,
S. Chilingaryan,
W. Choi,
D. Diaz Barrero,
K. Debowski,
M. Deffert,
M. Descher,
P. J. Doe,
O. Dragoun,
G. Drexlin,
S. Dyba
, et al. (104 additional authors not shown)
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 of mass $m_{4}$. The analysis is sen…
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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 of mass $m_{4}$. The analysis is sensitive to a fourth mass state $m^2_{4} \lesssim$ 1000 eV$^2$ and to active-to-sterile neutrino mixing down to $|U_{e4}|^2 \gtrsim 2\cdot10^{-2}$. No significant spectral distortion is observed and exclusion bounds on the sterile mass and mixing are reported. These new limits supersede the Mainz results and improve the Troitsk bound for $m^2_{4} <$ 30 eV$^2$. The reactor and gallium anomalies are constrained for $ 100 < Δ{m}^2_{41} < 1000$ eV$^2$.
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Submitted 10 November, 2020;
originally announced November 2020.
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First operation of the KATRIN experiment with tritium
Authors:
M. Aker,
K. Altenmüller,
M. Arenz,
W. -J. Baek,
J. Barrett,
A. Beglarian,
J. Behrens,
A. Berlev,
U. Besserer,
K. Blaum,
F. Block,
S. Bobien,
B. Bornschein,
L. Bornschein,
H. Bouquet,
T. Brunst,
T. S. Caldwell,
S. Chilingaryan,
W. Choi,
K. Debowski,
M. Deffert,
M. Descher,
D. Díaz Barrero,
P. J. Doe,
O. Dragoun
, et al. (146 additional authors not shown)
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 beta-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.…
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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 beta-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 0.2 eV 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.
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Submitted 13 September, 2019;
originally announced September 2019.
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An improved upper limit on the neutrino mass from a direct kinematic method by KATRIN
Authors:
M. Aker,
K. Altenmüller,
M. Arenz,
M. Babutzka,
J. Barrett,
S. Bauer,
M. Beck,
A. Beglarian,
J. Behrens,
T. Bergmann,
U. Besserer,
K. Blaum,
F. Block,
S. Bobien,
K. Bokeloh,
J. Bonn,
B. Bornschein,
L. Bornschein,
H. Bouquet,
T. Brunst,
T. S. Caldwell,
L. La Cascio,
S. Chilingaryan,
W. Choi,
T. J. Corona
, et al. (184 additional authors not shown)
Abstract:
We report on the neutrino mass measurement result from the first four-week science run of the Karlsruhe Tritium Neutrino experiment KATRIN in spring 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are energy analyzed by a high-resolution MAC-E filter. A fit of the integrated electron spectrum over a narrow interval around the kinematic endpoint at 18.57 keV gives an…
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We report on the neutrino mass measurement result from the first four-week science run of the Karlsruhe Tritium Neutrino experiment KATRIN in spring 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are energy analyzed by a high-resolution MAC-E filter. A fit of the integrated electron spectrum over a narrow interval around the kinematic endpoint at 18.57 keV gives an effective neutrino mass square value of $(-1.0^{+0.9}_{-1.1})$ eV$^2$. From this we derive an upper limit of 1.1 eV (90$\%$ confidence level) on the absolute mass scale of neutrinos. This value coincides with the KATRIN sensitivity. It improves upon previous mass limits from kinematic measurements by almost a factor of two and provides model-independent input to cosmological studies of structure formation.
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Submitted 13 September, 2019;
originally announced September 2019.
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High-resolution spectroscopy of gaseous $^\mathrm{83m}$Kr conversion electrons with the KATRIN experiment
Authors:
K. Altenmüller,
M. Arenz,
W. -J. Baek,
M. Beck,
A. Beglarian,
J. Behrens,
T. Bergmann,
A. Berlev,
U. Besserer,
K. Blaum,
F. Block,
S. Bobien,
T. Bode,
B. Bornschein,
L. Bornschein,
T. Brunst,
N. Buzinsky,
S. Chilingaryan,
W. Q. Choi,
M. Deffert,
P. J. Doe,
O. Dragoun,
G. Drexlin,
S. Dyba,
F. Edzards
, et al. (102 additional authors not shown)
Abstract:
In this work, we present the first spectroscopic measurements of conversion electrons originating from the decay of metastable gaseous $^\mathrm{83m}$Kr with the Karlsruhe Tritium Neutrino (KATRIN) experiment. The results obtained in this calibration measurement represent a major commissioning milestone for the upcoming direct neutrino mass measurement with KATRIN. The successful campaign demonstr…
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In this work, we present the first spectroscopic measurements of conversion electrons originating from the decay of metastable gaseous $^\mathrm{83m}$Kr with the Karlsruhe Tritium Neutrino (KATRIN) experiment. The results obtained in this calibration measurement represent a major commissioning milestone for the upcoming direct neutrino mass measurement with KATRIN. The successful campaign demonstrates the functionalities of the full KATRIN beamline. The KATRIN main spectrometer's excellent energy resolution of ~ 1 eV made it possible to determine the narrow K-32 and L$_3$-32 conversion electron line widths with an unprecedented precision of ~ 1 %.
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Submitted 18 March, 2019; v1 submitted 15 March, 2019;
originally announced March 2019.
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Muon-induced background in the KATRIN main spectrometer
Authors:
K. Altenmüller,
M. Arenz,
W. -J. Baek,
M. Beck,
A. Beglarian,
J. Behrens,
T. Bergmann,
A. Berlev,
U. Besserer,
K. Blaum,
S. Bobien,
T. Bode,
B. Bornschein,
L. Bornschein,
T. Brunst,
N. Buzinsky,
S. Chilingaryan,
W. Q. Choi,
M. Deffert,
P. J. Doe,
O. Dragoun,
G. Drexlin,
S. Dyba,
F. Edzards,
K. Eitel
, et al. (109 additional authors not shown)
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 part…
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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.
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Submitted 13 December, 2018; v1 submitted 30 May, 2018;
originally announced May 2018.
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First transmission of electrons and ions through the KATRIN beamline
Authors:
M. Arenz,
W. -J. Baek,
M. Beck,
A. Beglarian,
J. Behrens,
T. Bergmann,
A. Berlev,
U. Besserer,
K. Blaum,
T. Bode,
B. Bornschein,
L. Bornschein,
T. Brunst,
N. Buzinsky,
S. Chilingaryan,
W. Q. Choi,
M. Deffert,
P. J. Doe,
O. Dragoun,
G. Drexlin,
S. Dyba,
F. Edzards,
K. Eitel,
E. Ellinger,
R. Engel
, et al. (104 additional authors not shown)
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 beta decay. This work documents several KATRIN commissioning milestones: the complete assembly of the experimental beamline, the successful transmission of electrons fr…
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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 beta 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 Kr-83m was injected into the KATRIN source section, and a condensed Kr-83m 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.
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Submitted 7 July, 2018; v1 submitted 12 February, 2018;
originally announced February 2018.
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Ultra-stable implanted 83Rb/83mKr electron sources for the energy scale monitoring in the KATRIN experiment
Authors:
M. Zbořil,
S. Bauer,
M. Beck,
J. Bonn,
O. Dragoun,
J. Jakůbek,
K. Johnston,
A. Kovalík,
E. W. Otten,
K. Schlösser,
M. Slezák,
A. Špalek,
T. Thümmler,
D. Vénos,
J. Žemlička,
C. Weinheimer
Abstract:
The KATRIN experiment aims at the direct model-independent determination of the average electron neutrino mass via the measurement of the endpoint region of the tritium beta decay spectrum. The electron spectrometer of the MAC-E filter type is used, requiring very high stability of the electric filtering potential. This work proves the feasibility of implanted 83Rb/83mKr calibration electron sourc…
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The KATRIN experiment aims at the direct model-independent determination of the average electron neutrino mass via the measurement of the endpoint region of the tritium beta decay spectrum. The electron spectrometer of the MAC-E filter type is used, requiring very high stability of the electric filtering potential. This work proves the feasibility of implanted 83Rb/83mKr calibration electron sources which will be utilised in the additional monitor spectrometer sharing the high voltage with the main spectrometer of KATRIN. The source employs conversion electrons of 83mKr which is continuously generated by 83Rb. The K-32 conversion line (kinetic energy of 17.8 keV, natural line width of 2.7 eV) is shown to fulfill the KATRIN requirement of the relative energy stability of +/-1.6 ppm/month. The sources will serve as a standard tool for continuous monitoring of KATRIN's energy scale stability with sub-ppm precision. They may also be used in other applications where the precise conversion lines can be separated from the low energy spectrum caused by the electron inelastic scattering in the substrate.
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Submitted 5 February, 2013; v1 submitted 20 December, 2012;
originally announced December 2012.
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Feasibility of photoelectron sources for testing the energy scale stablity of the KATRIN beta-ray spectrometer
Authors:
O. Dragoun,
A. Spalek,
J. Kaspar,
J. Bonn,
A. Kovalik,
E. W. Otten,
D. Venos,
Ch. Weinheimer
Abstract:
Photoabsorption of nuclear gamma-rays in thin metallic convertors was examined with the aim to produce monoenergetic photoelectrons of kinetic energy around 18.6 keV and natural width of about 1 eV. Calculations were carried out for commercial photon sources of 241Am (1.1 GBq) and 119mSn (0.5 GBq) irradiating Co and Ti convertors. Photoelectrons ejected by 241Am gamma- and X-rays from Co convertor…
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Photoabsorption of nuclear gamma-rays in thin metallic convertors was examined with the aim to produce monoenergetic photoelectrons of kinetic energy around 18.6 keV and natural width of about 1 eV. Calculations were carried out for commercial photon sources of 241Am (1.1 GBq) and 119mSn (0.5 GBq) irradiating Co and Ti convertors. Photoelectrons ejected by 241Am gamma- and X-rays from Co convertors of various thickness were measured with two electrostatic spectrometers.
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Submitted 19 March, 2010;
originally announced March 2010.
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Distribution of the 83Rb/83mKr activity on vacuum evaporated samples examined with the Timepix position sensitive detector
Authors:
D. Venos,
J. Jakubek,
O. Dragoun,
S. Pospisil
Abstract:
Properties of vacuum evaporated 83Rb/83mKr sources of low-energy conversion electrons, which are under development for monitoring the energy scale stability of the Karlsruhe Tritium Neutrino experiment KATRIN, were examined by the Timepix pixel detector exhibiting the position resolution of at least 55 microm. No distinct local inhomogeneities in the surface distribution of 83Rb/83mKr were obser…
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Properties of vacuum evaporated 83Rb/83mKr sources of low-energy conversion electrons, which are under development for monitoring the energy scale stability of the Karlsruhe Tritium Neutrino experiment KATRIN, were examined by the Timepix pixel detector exhibiting the position resolution of at least 55 microm. No distinct local inhomogeneities in the surface distribution of 83Rb/83mKr were observed. The source diameter derived from the recorded image agrees within 5 % with that expected from evaporation geometry. More precise determination of the actual source diameter is complicated by Compton scattered electrons caused by 83Rb gamma-rays.
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Submitted 22 December, 2007;
originally announced December 2007.
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On the reliability of the theoretical internal conversion coefficients
Authors:
M. Rysavy,
O. Dragoun
Abstract:
Possible sources of uncertainties in the calculations of the internal conversion coefficients are studied. The uncertainties induced by them are estimated.
Possible sources of uncertainties in the calculations of the internal conversion coefficients are studied. The uncertainties induced by them are estimated.
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Submitted 16 June, 2000;
originally announced June 2000.
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Internal conversion coefficients for superheavy elements
Authors:
O. Dragoun,
M. Rysavy,
A. Spalek
Abstract:
The internal conversion coefficients (ICC) were calculated for all atomic subshells of the elements with 104<=Z<=126, the E1...E4, M1...M4 multipolarities and the transition energies between 10 and 1000 keV. The atomic screening was treated in the relativistic Hartree-Fock-Slater model. The Tables comprising almost 90000 subshell and total ICC were recently deposited at LANL preprint server.
The internal conversion coefficients (ICC) were calculated for all atomic subshells of the elements with 104<=Z<=126, the E1...E4, M1...M4 multipolarities and the transition energies between 10 and 1000 keV. The atomic screening was treated in the relativistic Hartree-Fock-Slater model. The Tables comprising almost 90000 subshell and total ICC were recently deposited at LANL preprint server.
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Submitted 7 April, 2000;
originally announced April 2000.
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Tables of internal conversion coefficients for superheavy elements
Authors:
M. Rysavy,
O. Dragoun
Abstract:
The internal conversion coefficients for the elements 104 <= Z <= 126 are presented.
The internal conversion coefficients for the elements 104 <= Z <= 126 are presented.
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Submitted 4 April, 2000;
originally announced April 2000.