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NEMO3 analysis and NEMO3 analysis and SuperNEMO developmentSuperNEMO development
Benjamin RichardsBenjamin Richards
Brief Nemo3 IntroBrief Nemo3 Intro The Neutrino Ettore Majorana Observatory (NEMO 3)
detector, which is now running in the Frejus Underground Laboratory and was begun more than ten years ago.
Description of detector Description of detector partsparts
Tracking wires
PMTs Source foil
Scintillator blocks wrapped in mylar
Last year: PMT coating / Last year: PMT coating / Analysis fitAnalysis fit
Development of PMT Development of PMT coating. coating. Shows Shows 10% ~ 15%increase in Q.E.
Wrote an automated Wrote an automated fit for Bifit for Bi207 207 energyenergy
spectrumspectrum
Experimented with Experimented with Phoswich ideaPhoswich idea
Photons
From
LED
Coating
Photo
cathode
layer
dynodes
No.
of
Eve
nts
ADC counts (Energy)
This year: Uniformity study of This year: Uniformity study of scintillator block for scintillator block for
SuperNEMOSuperNEMO
PMT 8”
Source
Energy bins
Frequency
Scintilator wrapped in PTFE 976 KeV electron
peak
Model of NEMO3 from TDRModel of NEMO3 from TDR
TDR Drawing
s
3D Reconstructi
on
Model of NEMO3 from TDRModel of NEMO3 from TDR
Neutrinoless double beta Neutrinoless double beta decaydecay
Theory for Theory for molybdenummolybdenum to to ground state and excited ground state and excited
statesstates We can calculate We can calculate
the matrix elements the matrix elements of other decay of other decay modes of modes of 100100Mo, To Mo, To more accurately more accurately estimate the matrix estimate the matrix element for the element for the neutrinoless double neutrinoless double beta decay. beta decay.
100Mo
γ
γ
100Ru
2e2ν
Cuts MadeCuts Made No. of scintillator hits = 2No. of scintillator hits = 2 No. of tracks = 2No. of tracks = 2 Check if scintillator hits have associated tracksCheck if scintillator hits have associated tracks Both tracks are from negatively charged particlesBoth tracks are from negatively charged particles Cut if track reconstruction failsCut if track reconstruction fails Cut on the source used (Mo only)Cut on the source used (Mo only) Cut if PMT is above max energy thresholdCut if PMT is above max energy threshold Cut if electrons are below 200KeVCut if electrons are below 200KeV Check track starts from first 4 tracking wiresCheck track starts from first 4 tracking wires Check track end on last 3 tracking wiresCheck track end on last 3 tracking wires TOF cut to check its an internal electronTOF cut to check its an internal electron Check if scintillator is isolatedCheck if scintillator is isolated
ResultsResults
Energy (MeV)
Energy (MeV) Energy (MeV)
Freq
uen
cyFre
qu
en
cy
Freq
uen
cyFre
qu
en
cy
Cos (θ)
1 Months data
ResultsResults
Active time over which data was used Active time over which data was used = 31.4648 days= 31.4648 days
No. of events that passed cuts = 18313 No. of events that passed cuts = 18313 ±135±135
Efficiency calculated from MC = 0.051Efficiency calculated from MC = 0.051 Half-life calculated = (6.90 Half-life calculated = (6.90 ± 0.05)± 0.05)x10x10
1818 yryr
events
/
N
tNT 021 )2ln(
What I will do in the futureWhat I will do in the future
Understand the backgrounds of the Understand the backgrounds of the experimentexperiment
Make analysis of Make analysis of 100100Mo transitions to Mo transitions to excited states for Ph IIexcited states for Ph II
Work on development for Work on development for SuperNemo, including work on the SuperNemo, including work on the module prototype.module prototype.
