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Low Energy Neutrino Astronomy in the
futurelarge-volume Liquid-Scintillator Detector
LENA Michael Wurm, F. v. Feilitzsch, M.
Göger-Neff, T. Lewke, T. Marrodán Undagoitia, L.
Oberauer, W. Potzel, S. Todor, J. Winter E15
Chair for Astroparticle Physics, Technische
Universität München, Physik Department,
James-Franck-Str., D-85748 Garching b. München,
Germany.www.e15.physik.tu-muenchen.de,
mwurm_at_ph.tum.de

DETECTOR LAYOUTCavernheight 115 m, diameter
50 mshielding from cosmic rays 4,000
m.w.e.Muon Vetoplastic scintillator panels (on
top)Water Cherenkov Detector3,000
phototubes100 kt of waterreduction of
fastneutron backgroundSteel Cylinderheight
100 m, diameter 30 m70 kt of organic
liquid 13,500 phototubesBufferthickness 2
mnon-scintillating organic liquidshielding from
external radioactivityNylon Vesselseparating
buffer liquidand liquid scintillatorTarget
Volumeheight 100 m, diameter 26 m50 kt of
liquid scintillator -vertical design is
favourable in terms of rock pressure and buoyancy
forces
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SOLAR NEUTRINOS Detection Channels -
neutrino-electron scattering ? Compton-like
shoulder- CC reaction on 13C (1 of
12C)Background Sources- external gammas/fast
neutrons - intrinsic contamination of the
liquid radionuclides as 210Po, 210Bi, 85Kr
etc. - µ-induced cosmogenic radionuclides 11C,
10C, 9Li, 8He, Scientific Motivation- search
for temporal variations in 7Be n flux due to
density/temperature fluctuations inside the
sun- probing the MSW effect in the vacuum
transition region ? new osc. physics- determine
contribution of CNO cycle to solar energy
production- search for ne?ne conversion
SUPERNOVA NEUTRINOS Neutrino Detection - SN of 8
solar masses, 10 kpc away 20,000 events in 10
seconds- event signatures and spatial reconstr.
allow to distinguish the flux and mean energy
of ne, ne and nx- golden channels the inverse
beta decay provides detailed information on
ne, proton recoils spectral information on
nx Scientific Motivation- information on
core-collapse SN average n energies of
neutrino flavours ratio of n flavour
luminosities overall normalisation of the
flux- information on neutrino properties
matter effects in SN envelope ? neutrino mass
hierarchy Earth matter effect ? strong bound
on value of q13
Channel thr (MeV)
ne p ? n e 1.8 9200
ne12C ?12N e- 17.3 250
ne12C ?12B e 13.4 500
nx12C ?12Cnx 15.1 1250
nx p ? p nx 0.2 2350
nx e- ? e- nx 0.2 700
ne13C ?13N e- 2.2 15
nx13C ?13C nx 3.7 20
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DETECTOR CONSTRUCTIONPreferred Location still
active Pyhäsalmi Cu/Ni-mine in central
FinlandDepth 1.4 km, laboratory will be
attached to the deepest mining levelLENA Time
Schedule for Pyhäsalmi 2012 start of
excavation 2016 detector construction
2020 filling of scintillator and water 2022
start of data taking
n type E (MeV) ev/d
7Be 0.86 5400
pep 1.44 210
CNO lt1.8 ? 300
8B (ne-scat.) lt15 50
8B (13C) lt15 1
EarthMatterEffect
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Work is in progress
Winter, dipl. thesis, Skadhauge, hep-ph/0611194
Dighe et al., hep-ph/0304150
TERRESTRIAL NEUTRINOS
LIQUID SCINTILLATORDEVELOPMENT Liquid
Scintillator consist of a solventand one or
several wavelength shiftersTested
MaterialsSolvents PXE, LAB, PC,
DodecaneFluors PPO, pTP, bisMSB,
PMP Scintillator Parameters and theirInfluence
on Detector Performance- density and chemical
composition ? volume, buoyancy, self-shielding
number of target protons, electrons
C-atoms - light yield and quenching ? energy
resolution, background identification-
absorption/emission spectra ? light propagation
in the scintillator- fluorescence decay times
? time resolution, particle identification
by pulse shape analysis - large-scale solvent
transparency absorption, re-emission,
scattering ? light propagation, effective light
yield and time resolution
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ne are produced by U/Th decay chains in the
Earths crust/mantle.Detection- channel
inverse beta decay, threshold of 1.8 MeV (no
40K)- expected rate 4x10(2-3) /yr- main
background reactor neScientific Motivation-
determine the contribution of radio- active
decays to Earths heatflow- measure the relative
contributions of U/Th decay chains- with a 2nd
detector like Hanohano disentangle U/Th
abundancies of oceanic and continental crust-
test of the hypothesis of a geo- reactor in the
Earths core (gt2TW)
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based on an on-going pre-feasibility study by
Rockplan Ltd.
LAGUNALarge Apparatus for Grand Unificationand
Neutrino Astrophysics coordinated RD design
studyin European collaboration, Laboratory site
study funded by EU
arXiv0705.0116
LENALiquid-Scintillator Detector,50 kt of
target, 15,000 PMs
MEMPHYSWater Cerenkov Detector500 kt target3
shafts3x 81k PMs
GLACIER, Liquid-Argon Detector100 kt target, 20m
drift length, LEM-foil readout28,000 PMs for
Cerenkov- and scintillation light
S. Enomoto, DOANOW07, Hochmuth et al.,
hep-ph/0509136
A MULTI-PURPOSE OBSERVATORY Further Fields of
Research - atmospheric neutrinos at low
energies- refined measurements of solar osc.
parameters using reactor neutrinos - indirect
search for MeV dark matter detection of
annihilation neutrinos- far detector for a
neutrino/beta beam
MC SIMULATIONS
investigatedsites
SITE STUDYCandidate Sites- Boulby, UK-
Canfránc, Spain- Fréjus, France- Pyhäsalmi,
Finland- Sieroszowice, Poland- Slanic,
RomaniaLAGUNA Collaboration- 100 scientists-
more than 20 institutes- 11 European countries
Purpose of MC- determine energy/time/spatial
resolution, capability of particle
identification etc. of the detector- test
influence of scintillator parameters to
optimize the composition of solvent/solutes
atmospheric nm rate in LENA,energy-
angular-dependent
energy dependenceof spatial resolution,light
yield 180 pe/MeV
Petcov, Schwetz,hep-ph/0607155 Measuring
reactor ns for solar oscillation parameters in
Fréjus
time profile10 MeV event, 5 m off-axis
Spectral signature of 20/60 MeV dark matter
annihilation neutrinosPalomares-Ruiz, Pascoli,
arXiv0710.5420
J. Winter, dipl. thesis
This work has been supported by funds of the
Maier-Leibniz-Laboratorium (MLL), the
Sonderforschungsbereich Transregio 27 Neutrinos
and Beyond, and the Excellence Cluster Origin
and Structure of the Universe.