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

3

1

222

iiei mUm

220 )( mEE

dEdN

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)

Simone.Rupp@kit.edu

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