Showing papers by "Sanshiro Enomoto published in 2018"
University of Bonn1, Karlsruhe Institute of Technology2, University of Mainz3, Russian Academy of Sciences4, Max Planck Society5, Technische Universität München6, Massachusetts Institute of Technology7, University of Washington8, University of Münster9, University of Wuppertal10, Carnegie Mellon University11, Complutense University of Madrid12, Durham University13, University of North Carolina at Chapel Hill14, Commissariat à l'énergie atomique et aux énergies alternatives15, Case Western Reserve University16, Lawrence Berkeley National Laboratory17, Humboldt University of Berlin18
TL;DR: 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.
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.
41 citations
University of Bonn1, Karlsruhe Institute of Technology2, University of Mainz3, Russian Academy of Sciences4, Max Planck Society5, Technische Universität München6, Massachusetts Institute of Technology7, University of Washington8, University of Münster9, University of Wuppertal10, Carnegie Mellon University11, Complutense University of Madrid12, University of North Carolina at Chapel Hill13, Durham University14, Commissariat à l'énergie atomique et aux énergies alternatives15, Case Western Reserve University16, Lawrence Berkeley National Laboratory17, Humboldt University of Berlin18
TL;DR: The KATRIN experiment as discussed by the authors used a chain of ten single solenoid magnets and two larger superconducting magnet systems to guide β-electrons from the source to the detector within a magnetic flux of 191 Tcm2.
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.
34 citations
University of Bonn1, Karlsruhe Institute of Technology2, University of Mainz3, Russian Academy of Sciences4, Max Planck Society5, Technische Universität München6, Massachusetts Institute of Technology7, University of Washington8, University of Münster9, University of Wuppertal10, Carnegie Mellon University11, Complutense University of Madrid12, University of North Carolina at Chapel Hill13, Commissariat à l'énergie atomique et aux énergies alternatives14, Case Western Reserve University15, Lawrence Berkeley National Laboratory16, Humboldt University of Berlin17
TL;DR: In this paper, the energy difference of two Kr conversion electron lines with the KATRIN setup was measured and the measured scale factor of the voltage divider K35 was shown to be in agreement with the last PTB calibration 4 years ago.
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 $$^{83{\mathrm{m}}}$$
Kr 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.
31 citations
University of Bonn1, Karlsruhe Institute of Technology2, University of Mainz3, Russian Academy of Sciences4, Max Planck Society5, Technische Universität München6, Massachusetts Institute of Technology7, University of Washington8, University of Münster9, University of Wuppertal10, Carnegie Mellon University11, Complutense University of Madrid12, University of North Carolina at Chapel Hill13, Durham University14, Commissariat à l'énergie atomique et aux énergies alternatives15, Case Western Reserve University16, Lawrence Berkeley National Laboratory17, Humboldt University of Berlin18
TL;DR: 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 as discussed by the authors.
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 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.
31 citations
TL;DR: The KATRIN experiment as discussed by the authors used a chain of ten single solenoid magnets and two larger superconducting magnet systems to determine the effective electron anti-neutrino mass from tritium beta decay with an unprecedented sub-eV sensitivity.
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 $\beta$-electrons from the source to the detector within a magnetic flux of 191~Tcm$^2$. 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.
25 citations
01 Sep 2018
TL;DR: The KATRIN experiment as mentioned in this paper used a MAC-E filter spectrometer 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 spectrum in the endpoint region.
Abstract: The KATRIN experiment aims to determine the effective electron neutrino mass with a sensitivity of $${0.2}{\hbox { eV/c}^{2}}$$0.2eV/c2 (%90 CL) by precision measurement of the shape of the tritium $$\upbeta $$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 $${}^{\text {219}}\text {Rn}$$219Rn and $${}^{\text {220}}\text {Rn}$$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.
7 citations
TL;DR: The KATRIN experiment as mentioned in this paper uses the shape of tritium β-spectrum in the endpoint region to determine the effective electron neutrino mass with a sensitivity of 90% C.L. The energy analysis of the decay electrons is achieved by a MAC-E filter spectrometer.
Abstract: The KATRIN experiment aims to determine the effective electron neutrino mass with a sensitivity of $0.2\,{\text{eV}/c^2}$ (90\% C.L.) by precision measurement of the shape of the tritium \textbeta-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 $\textsuperscript{219}$Rn and $\textsuperscript{220}$Rn, 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.
5 citations
University of Bonn1, Karlsruhe Institute of Technology2, University of Münster3, University of Mainz4, Russian Academy of Sciences5, Max Planck Society6, Technische Universität München7, Massachusetts Institute of Technology8, University of Washington9, University of Wuppertal10, Carnegie Mellon University11, Complutense University of Madrid12, Durham University13, University of North Carolina at Chapel Hill14, Commissariat à l'énergie atomique et aux énergies alternatives15, Case Western Reserve University16, Lawrence Berkeley National Laboratory17, Humboldt University of Berlin18, Oak Ridge National Laboratory19
TL;DR: The KATRIN experiment as discussed by the authors used a MAC-E filter spectrometer to determine the effective electron neutrino mass by precision measurement of the shape of the tritium spectrum in the endpoint region.
Abstract: The KATRIN experiment aims to determine the effective electron neutrino mass with a sensitivity of $${0.2}{\hbox { eV/c}^{2}}$$
(%90 CL) by precision measurement of the shape of the tritium $$\upbeta $$
-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 $${}^{\text {219}}\text {Rn}$$
and $${}^{\text {220}}\text {Rn}$$
, 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.
4 citations
University of Bonn1, Karlsruhe Institute of Technology2, University of Mainz3, Russian Academy of Sciences4, Max Planck Society5, Technische Universität München6, Massachusetts Institute of Technology7, University of Washington8, University of Münster9, University of Wuppertal10, Carnegie Mellon University11, Complutense University of Madrid12, University of North Carolina at Chapel Hill13, Commissariat à l'énergie atomique et aux énergies alternatives14, Case Western Reserve University15, Lawrence Berkeley National Laboratory16, Humboldt University of Berlin17
TL;DR: In this article, the energy difference of two $83\mathrm{m}}$Kr conversion electron lines with the neutrino mass experiment KATRIN setup is measured.
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 $^{83\mathrm{m}}$Kr 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 four years ago. This result demonstrates the utility of the calibration method, as well as the long-term stability of the voltage divider.