Search results for "KATRIN"
showing 10 items of 30 documents
Commissioning of the vacuum system of the KATRIN Main Spectrometer
2016
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 m[superscript 3], 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 ha…
How Critical Infrastructure Orients International Relief in Cascading Disasters
2016
Critical infrastructure and facilities are central assets in modern societies, but their impact on international disaster relief remains mostly associated with logistics challenges. The emerging literature on cascading disasters suggests the need to integrate the nonlinearity of events in the analyses. This article investigates three case studies: the 2002 floods in the Czech Republic, Hurricane Katrina in 2005 and the 2011 Tohoku earthquake, tsunami and Fukushima meltdown in Japan. We explore how the failure of critical infrastructure can orient international disaster relief by shifting its priorities during the response. We argue that critical infrastructure can influence aid request and …
Biblical Echoes and Communal Home in Jesmyn Ward's Salvage the Bones
2020
Jesmyn Ward’s second novel, Salvage the Bones (2011), offers a literary account of an African American family in dire poverty struggling to weather the horrors of Hurricane Katrina on the outskirts of Bois Sauvage, Mississippi. This article focuses on the novel’s ‘ideology of form’, which is premised on biblical models of narration —grounded on a literary transposition of The Book of Deuteronomy— that serves to portray the victimization of African Americans in mythical tones to evoke the country’s failed covenant between God and his chosen people. It also brings into focus the affective bonds of unity and communal healing relying on the idiosyncratic tenet of home understood as national spa…
Impact of a cryogenic baffle system on the suppression of radon-induced background in the KATRIN Pre-Spectrometer
2018
The KATRIN experiment will determine the effective electron anti-neutrino mass with a sensitivity of 200 meV/c2 at 90% CL. The energy analysis of tritium β-decay electrons will be performed by a tandem setup of electrostatic retarding spectrometers which have to be operated at very low background levels of <10−2 counts per second. This benchmark rate can be exceeded by background processes resulting from the emanation of single 219,220Rn atoms from the inner spectrometer surface and an array of non-evaporable getter strips used as main vacuum pump. Here we report on the impact of a cryogenic technique to reduce this radon-induced background in electrostatic spectrometers. It is based on ins…
Exact relativistic beta decay endpoint spectrum
2007
5 pages, 3 figures.-- PACS nrs.: 14.60.Pq; 13.30.-a; 23.40.-s; 23.40.Bw.-- ISI Article Identifier: 000250620900070.-- ArXiv pre-print available at: http://arxiv.org/abs/0706.0897
High-resolution spectroscopy of gaseous $^\mathrm{83m}$Kr conversion electrons with the KATRIN experiment
2020
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 %.
T2-beta-spectroscopy at KATRIN and the challenge of controlling the electrostatic potentials
2013
Abstract The KATRIN-Collaboration at KIT-Karlsruhe is setting up a huge electrostatic spectrometer in order to search for the absolute value of the neutrino mass from the beta-spectrum of molecular tritium with a sensitivity limit of 0.2 eV. Apart from high intensity, high resolution and low background, this goal requires control of the 18.6 kV filter potential on the ppm level. The paper starts with discussing the impact of uncertainties of beta-endpoint, energy loss and filter potential on the uncertainty of the neutrino mass. Then it describes the various measures for controlling the applied high voltage as well as the potential distribution within the spectrometer and the gaseous tritiu…
First operation of the KATRIN experiment with tritium
2020
AbstractThe 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 $$\upbeta $$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 $$0.2\hbox { eV}$$0.2eV ($$90\%$$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 …
First transmission of electrons and ions through the KATRIN beamline
2018
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, …
The Cryogenic Pumping Section of the KATRIN Experiment
2010
In order to determine the absolute scale of the neutrino mass with a sensitivity of 0.2 (90% Confidence Level), the Karlsruhe Tritium Neutrino experiment (KATRIN) operates a series of superconducting magnet systems, which guide the electrons adiabatically from the source of tritium beta-decay to the detector within a magnetic flux of 191 . The 7 m long Cryogenic Pumping Section (CPS) is designed as the final barrier of tritium circulation. It has to reduce the tritium partial pressure below Pa in order to limit the background count rate in the measurement. To achieve this, the tritium entering the CPS must be adsorbed onto a pre-condensed argon layer on the inner surface of the beam tube at…