KIT – University of the State of Baden-Wuerttemberg andNational Research Center of the Helmholtz Association
Raman spectroscopy for the Windowless Gaseous Tritium Source of the KATRIN experimentSimone Rupp for the KATRIN Collaboration
The KATRIN experiment
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1
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Essential for KATRIN sensitivity:Control and monitoring of
source parameters on 0.1% levelM
. Bab
utzk
a et
al.,
New
J. P
hys.
14
(201
2) 1
0304
6
• Model-independent measurement of the neutrino mass, based on kinematics of b-decay
•200 meV sensitivity (90% C.L.) on neutrino mass
The WGTS cryostat
Source activity: 1011 e- / sThroughput: 10 kg tritium/year in closed tritium cycleRequirements: 0.1% stability for small systematic uncertainties
S. F
isch
er e
t al.,
Fus
ion
Sci
. Tec
hnol
., 60
3 9
25 (2
011)
Measurement principle
DetectorSpectrometers
Transport sectionTritium source (WGTS)CMS
KATRIN Setup
More about KATRIN:
Talk by T. Thümmler
Thursday, 18:58,
Working Group 2
The Windowless Gaseous Tritium Source (WGTS)
Perm
eato
r
T2
Waste
Principle of the WGTS
p- & T-controlled
buffer vessel
Buffer vessel
Pump
Raman
Column density stabilityAchievements:
Pressure: 0.02% stabilityTemperature: 0.005% stability
Gas composition monitoringAchievements:
Precision < 0.1% in 60 sCalibration uncertainty < 3%
Control and monitoring
Raman spectroscopy – a high precision composition monitoring tool for KATRIN
LARA cell
Quantitative analysis of gas sample composition based on Raman line intensities
Characteristic wavelength shift for each molecule simultaneous detectionContact-free, in-line gas analysis
Long term measurementObservation of
Exchange reactionsSurface reactionsImpurities
0.1% precision verified under
realistic conditions
Institute of Experimental Nuclear Physics & Institute of Technical Physics, KIT