Gd Liquid scintillator: completion of the R

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Gd Liquid scintillator completion of the RD!

• LENS RD ? new metal ß-diketone molecule (MPIK)
• Stable 0.1 Gd-Acac (few months)
• Baseline receipie 80 mineral oil 20 PXE
  Fluors wavelenght shifters
• In-loaded scintillators (0.1 , 5 loading) are
  counting _at_Gran Sasso
• Spare stable receipies available (MPIK, INFN/LNGS)

Stability 0,1 Gd in PXE
3Gd
Gd-Acac molecule

• Completion of the RD first half of 2004
• Choice of the final scintillator
• Stability Material compatibility ? Aging tests
  (MPIK, Saclay)

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Gd Liquid scintillator tests in Saclay

• Goal 1/ Test the LONG term stability of the
  scintillator
• 2/ Test the material compatibility with acrylic,
  glue, ...
• ? Towards the desgin of the acrylic vessels
• Tight stainless steel boxes flushed with N2 20-
  130cl quartz cuvettes
• Aeging test ? scintillator temperature 50
  degrees
• Systematic periodic photospectrometer absorbance
  measurements

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Acrylic vessels
Gamma catcher
Target
Final assembly (in several part) In Choozs site
Assembly in the manufacturer workshop
3.6m
2.4m
4m
2.8m
2m
Thickness 6mm
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Stress in acrylic vessels

• Suspension
• 3 points at 120 degrees
• Thickness 6 mm
• Empty weight
• Target 220kg
• Gamma catcher 470kg
• ? Maximum stress 12 MPa

Target
Gamma catcher
DAPNIA/SIS/LCAP - JMB
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Filling of vessels Dosing pums (diaphragm pumps
or peristaltic pumps) accuracy 1 Pump
electronic flowmeter accuracy 0.5 Weight
density measurements Density accuracy 0.001
g/cm3 (can reach 0.0001 g/cm3) Weigth accuracy
lt10 kg on 12 tons. -gtvolume 0.1
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Full detector simulationPCC APC, Kurchatov
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Parameters used for the simulation
Reactor thermal power 8.4 GW Near detector
distance 150 meters Volume N F 12.67
m3 Far detector distance 1050 meters
with PXE gt 12.5 tons Near detector efficiency
32 50 dead time x 80 global load factor x
80 detection Far detector efficiency 64 No
dead time x 80 global load factor x 80
detection Standard systematic errors
absolute
1 par fit
relative
backgrounds
or
with
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Sensitivity at 90 C.L. if sin2(2?13)0 versus
integrated luminosity in RNU
sabs 2 srel 0.6 sshape 2 sb2b 1
New target composition increases luminosity by 30

Reactor 1 (2 RNU)
Reactor 2 (40 RNU)
1 RNU 200 t.GW.y
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Summary outlook _at_Double-CHOOZ

• Support for the EDF power company to do a 2nd
  experiment _at_CHOOZ
• Double-CHOOZ sensitivity sin2(2?13)lt0.03, 90
  C.L. (?m2 2.0 10-3 eV2)
• Current limint CHOOZ sin2(2?13)lt0.2 ?
  discovery potential !
• Technology / design well known (CHOOZ, BOREXINO,
  KamLAND, )
• ? few RD needed Gd loading (stability)
  material compatibility
• (Started, to be completed in half a year)
• Proto-collaboration PCC, Saclay, APC, TUM, MPIK,
  Tubingen, Kurchatov, Italy (likely to grow during
  the winter)
• ? (maxi-)letter of intent (February 2004) ?
  final proposal (6 months)
• Experiment cost, Double-CHOOZ case
• 2 x 13 tons, preliminary detector cost lt10
  Meuros (Civil engineering not included)
• Our Goal _at_Double- CHOOZ Construction starts end
  of 2005
• Start
  data taking in 2007-2008

2004
2005
2006
2007
2008
2009
2003
Site
Data taking
Prop.
Construction ?
design
Far detector starts
lt sin2(2?13) lt 0.025-003
lt sin2(2?13) lt 0.04
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