systematic effects in laser raman measurements for katrin · systematic effects in laser raman...
TRANSCRIPT
![Page 1: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/1.jpg)
KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH) www.kit.edu
Systematic effects in Laser Raman measurements for KATRIN
Magnus Schlösser
IEKP, Universität
Karlsruhe (TH)
Teilprojekt
A1
![Page 2: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/2.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)2
Content
LARA for KATRIN
Fundamentals
Setup of Laser-Raman system
Systematic effectDetection limitBackground featuresLong term stability
Quantitative analysis
Summary / Outlook Tritium Laboratory Karlsruhe
![Page 3: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/3.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)3
CMS
The KATRIN-Experiment
column density
ρd
= 5·1017cm-2
tritium injection rate qin
= 1.8 mbar l s-1
beam tube temperature T = 30 Ktritium purity
εT
≥
95%
Main spectrometer
Detector
WGTS
Transport section
Laser-Raman Spectroscopymonitoring
Source strength = AQ
·
ρd · εT
stability in the range of 10-3
![Page 4: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/4.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)4
Isotopic purity (εT
)
T2
DT
HT
H2
D2
HD
Isotopologues of hydrogen
Requirements for LARAMeasurement of tritium purity before injection into WGTS with a precision of 0,1 %Determination of isotopologue compositionAcquisition time as short as possible (minutes)Entire T2 pumped through LARA-cell (no Bypass)
Direct contribution to count rate at endpoint
Different final states
![Page 5: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/5.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)5
LARA for KATRIN
Q = H, D, T
Tritium throughput
40 g/d
=
1,5·1016
Bq/d
ISS glove box
Inner LoopOuter Loop
FIRC
PIRCA±
from TLK isotope
separation system
palladiummembran
filterbuffer
vessel
(pure
T2
)
pressurecontrolled
WGTS
buffer
vessel
Q2 only
beam tube to spectrometers
transferpump
to TLK tritium recovery and purification system
gaseouswastebuffervessel
LARA-Measurements @ p ≈
100 mbar
Flow diagram of Inner Loops and
Source
![Page 6: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/6.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)6
FundamentalsLight scattering on molecules elastic collisions
Rayleigh-scattering
wavelength of photons invariantmolecule remains in state of
excitement
![Page 7: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/7.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)7
elastic
collisions
Rayleigh-scattering
wavelength of photons invariantmolecule remains in state of
excitement
FundamentalsLight scattering on molecules
inelastic collisions
Raman-scattering
photon loses a fraction of its energy wavelength increases
energy is transferred to moleculevice versa process also possible!
Rotation Vibration
![Page 8: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/8.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)8
Fundamentals
Spectrum of different gasesexcitation with 532 nm
simulated spectrum
(SpecGen)
Rotational
Rotation-vibrational
S0 -branch
Q1 -branch
S1 -branchO1 -branch
![Page 9: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/9.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)9
Fundamentals
Spectrum of different gases
quantitative analysis of mixture possible
simulated spectrum
(SpecGen)
excitation with 532 nm
![Page 10: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/10.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)10
Setup of LARA-system
Laser
5W 532 nm
CCD
Filter
Spectrometer
Fibre
LARA-cell
Photo diode
developed over more than 2 years in collaboration with U Swansea
![Page 11: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/11.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)11
Setup of LARA-system1:1 image of scattered light on a fibre bundle
Laser-Raman-CellVolume: 7,1 cm3
Operation: „static“ or „in flow“
Laser beam
Raman-Collection
axis (90°)
Collection optics
Fibre
Fibre48 single fibres adjoining simple adjustmentrobust construction
![Page 12: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/12.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)12
Setup of LARA-systemTransmission Spectrometer
high light throughput high intensitymoderate resolution 600mm-1 covers region of interest
CCD2048 x 512 Pixelcooled down to -75° C
designed for detection of minimal intensities
Diffraction grating
Detector plane
532 nm edge filter Fibre connection
![Page 13: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/13.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)13
Detection limit
Detection limit for hydrogen isotopologues < 0,06 mbar partial
pressure
(250s, 5W)
tottot
min psignal
level-noise2p ⋅⋅
=∑
Detection limitPeak height ≈
2 ·
noise-levelThis sample:
Total pressure:
ptot
≈
110 mbarnoise-level = 0.32Sum of all 6 peak intensities:
Σtot
signal
= 1274minimal detectable partial pressure:
![Page 14: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/14.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)14
Background featuresSpectrum of T / D / H -mixture Spectrum of evacuated cell
Raman-scattering in SiO2
LARA -
Cell
Reflections on windows
acq.time
= 250 s acq.time
= 1000 s
![Page 15: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/15.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)15
Precision
PrecisionNoiseΔI=Signal
Isotop. Intensity S/N Precision
= N/S
T2 33 108 0.92 %DT 139 462 0.22 %HT 190 636 0.15 %D2 148 494 0.20 %HD 417 1392 0.07 %H2 318 1060 0.09
%
NoiseDefinition: Noise-amplitude N = 2 σ
2 σ
2 σ
![Page 16: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/16.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)16
Stability of long term runsTest of stability
Repeated measurements of static mixtureAll fluctuations are related to acquisition and analysisCalculate σ
for each peak from all acquisitions
Long term run
(p≈100mbar) 1329 x 250 s = 95 h
HD Intensity precision
Abs. 431 0.82%
Rel. 33.84 % 0.31%
T2 Intensity precision
Abs. 29 2.21%
Rel. 2.28 % 1.98%
Highest fraction in KATRIN will be T2 (95%) ≈
3 x HD(this
Run)
0.1% seems to be feasible in 250 s
![Page 17: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/17.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)17
Stability of long term runsLong term measurement -
Laser power
Diametric trend of laser power / background visible!
Wear out of coating? Thermal misalignment? Pointing stability?
▬ Laser power
(photo
diode)
▬ Background intensity
▬ Peak
Intensity
![Page 18: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/18.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)18
Stability of long term runs
Influence on laser powerand background
scattering region
beam width≈20µm
Pointing stability Thermal lensing Dust on optics or laser beam
-
Trace laser beam with modified webcam
-
Laser service
-
Keep dust out (Tubes)-
Sequential shutter up/down measurements
![Page 19: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/19.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)19
Stability of the Laser Raman SystemLong term measurement
Peak stability for accumulated intensity values100 mbar
1x25
0s
2x25
0s3x
250s # of accumulations
Sensitivity to fast changes
Precision
![Page 20: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/20.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)20
Quantitative analysis
Until now: Investigation of systematic effect via peak area
measurementsrelative spectral intensities not proportional to relative composition
Indirect Hard ModellingUses quantum mechanical models for quantitative
analysisFurther advantage: Use of theoretical known peak shapes reduces systematic uncertainties
(e.g. base line detection)
Intensities from QM
Spectrometer
resolution
Spectral
efficiency
Theoretical model
+ +
![Page 21: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/21.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)21
Indirect Hard ModellingPrinciple of indirect hard modelling
Measured spectrum
Pure substance spectra
H2
HD
D2
+IHM Fit
Prediction from spectral weights and calibration data
![Page 22: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/22.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)22
Indirect Hard Modelling
Precision T2 HD
“Peak areas” 1.50% 0.28%IHM 1.02% 0.20%
Most KATRIN-a-like measurement
(p≈100mbar, 250s)
each time analysis of 322 spectra
Comparison of precision (First results)First tests (demonstration)
semi-quantum mechanical model
usedspectral corrections missingno calibration
Stability of relative measurements
IHM increases precision by about 30%
![Page 23: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/23.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)23
Summary and OutlookLaser Raman monitors the isotopic purity for KATRINSystem has been invested for more than 8 month on systematic effects (e.g. background, long term stability,…)
StatusKATRIN requirements (0.1% precision) reachable At the moment: Laser stability is not satisfyingIHM method can improve analysis precision and allows quantitative analysisActual detection limit < 0.06 mbar in 250 s
Next stepsInvestigations and improvements of laser stabilityTheoretical modelling and spectra corrections for IHMDetermination of spectroscopic data for tritium
Michael Sturm, Sebastian Fischer, Helmut Telle, Richard Lewis, Magnus Schlösser, Beate
Bornschein
![Page 24: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/24.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)24
![Page 25: Systematic effects in Laser Raman measurements for KATRIN · Systematic effects in Laser Raman measurements for KATRIN Magnus Schlösser IEKP, Universität Karlsruhe (TH) ... Magnus](https://reader030.vdokument.com/reader030/viewer/2022021804/5b9f54fd09d3f26e288cae55/html5/thumbnails/25.jpg)
Magnus Schlösser | SFB - Transregio 27 Heidelberg | 10.July 2009KIT – die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)25
Data-Processing
MVA (IHM,…)MVA (IHM,…)
KATRIN-
Database
KATRIN-
DatabaseLARALARA
Spectrum-
Pre-
Processing
Spectrum-
Pre-
Processing
Training spectra
Training spectra
unknown
sample
unknown
sample compositioncomposition
“hard model”“hard model”
raw data
cleaned spectra
rel. composition
IHM:
Indirect Hard Modelling
Add quantum efficiency of integral system
Add quantum efficiency of integral system