Transcript Low radioactivity at the Modane Underground Laboratory Pia Loaiza Laboratoire Souterrain de Modane, France LRT 2004 12-13 Dec.

Low radioactivity at the Modane
Underground Laboratory
Pia Loaiza
Laboratoire Souterrain de Modane, France
LRT 2004
12-13 Dec. 2004, Sudbury, Canada
LABORATOIRE SOUTERRAIN DE MODANE
Located in the French-Italian border,
under the Fréjus peak.
Depth : 1750 m of rock (4800 m.w.e)
French laboratory operated by
Commissariat à l’Energie Atomique and
Centre National de la Recherche Scientifique.
Entrance of the tunnel view from the office building.
FRANCE
Altitudes
Distances
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1228 m
0 m
ITALIE
1263
6210
m
m
Low radioactivity at LSM
1298
m
12 868
m
Pia Loaiza
LABORATOIRE SOUTERRAIN DE MODANE
• 4 muons/m2/day
• 1.6 10-6 fast neutrons/cm2/s from rock/concrete
radioactivity
• Air continously renewed : 2 vol/hour
• 222Rn concentration 5-10 Bq/m3
Entrance to the Lab at the
mid-point of the
Fréjus road tunnel
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Low radioactivity at LSM
Pia Loaiza
PEOPLE AT LSM
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Low radioactivity at LSM
Pia Loaiza
EDELWEISS : Dark matter WIMP search
EDELWEISS II
French German collaboration
• Start installation beginning 2005
• Data taking: summer 2005 w. 28
detectors =>9 kg
• Upgrade to 100 detectors 36 kg
2006
Dubna integration in progress
• Neutron detectors w VETO m
EDELWEISS II
sensitivity goal
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Low radioactivity at LSM
EDELWEISS I
exclusion limits present
Pia Loaiza
NEMO 3 : Neutrinoless double beta decay
NEMO 3 collaboration :
France, Czech Republic, USA,
Russia, Japan, Great Britain
May 2004
August 2001
Start taking data February 2003
May 2004 : Radon purification
Water tank
system.
wood
coil
Iron shield
Tent surrounding the detector
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Low radioactivity at LSM
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TGV-2 : CSNSM-Dubna
10 g of 48Ca for 2
10 g of 106Cd for ECEC
Neutron
moderator
Sample
(Os-500 g)
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3He-counters
Super Heavy
elements In
Nature
Low radioactivity at LSM
Pia Loaiza
Radon trapping facility
Installation September 2004
Radon trapping facility
Radon purification by adsorption in charcoal
Time during which radon is trapped
in the « filter » : Tr = K(T) M / Q
K(T) : dynamic adsorption coeff.
M : charcoal mass
Q : Air rate
2 charcoal towers :
T1 = -53 C, T2 = -45 C
M = 2 x 450 kg
Vol. clean air : 125 m3/h
Activity 222Rn = 15 mBq/m3
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Low radioactivity at LSM
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Ge detectors at LSM
13 germanium detectors to measure low radioactivity levels
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Low radioactivity at LSM
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Ge detectors at LSM
Applications :
• Test of materials for EDELWEISS, NEMO
and ultra low background instrumentation.
• Measurement of environmental radioactivity
Radionuclides in the U and Th decay series are useful
chronometers for the determination of many processes in
the environment. The low natural radioactivity
encountered necessitate instrumentation capable of
measuring very low radionuclide concentrations.
Some applications :
Quantitative evaluation of both horizontal and vertical mixing
rates in the open ocean.
Determination of the rate of particle deposition on the marine
sediment layer (originated by both biological and physical
processes).
The decay of 210Pb provides a dating method which has been
applied to lake sediments.
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Low radioactivity at LSM
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Ge detectors at LSM
Applications :
Bordeaux wine dating
The concentration of 137Cs
provides a simple method to
estimate the wine age.
Monitoring of radioactive
contamination in the atmosphere
Measurements of artificial radionuclides in certain
samples require very low backgrounds.
Those measurements are carried out at the LSM.
7Be
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and 137Cs concentration in the atmosphere
Low radioactivity at LSM
Pia Loaiza
Ge detectors at LSM
Detector
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Type
Volume
Total and peak background rate (counts/day)
40-2700 keV
352 keV
583 keV
1461 keV
MONDEUSE
well
220 cc
770
4.2
2.7
5
ROUSSETE
well
430 cc
692
4.1
2.9
7.2
ABYMES
well
980 cc
828
5.6
5.6
5.6
XXL
well
844 cc
821
6.8
<1.8
11.6
HERMINE
N
197 cc
313
1.2
1.5
2.3
HELLAZ
P
204 cc
515
4.5
0.5
1.4
JASMIN
P
380 cc
529
2.0
1.41
1.71
GENTIANE
N
215 cc
178
<0.21
0.38
0.65
IRIS
P
400 cc
282
1.02
1.46
3.01
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ILIAS : Integrated Large Infrastructures
for Astroparticle Science
ILIAS is an initiative proposed for funding by the European Union.
ILIAS
Theoretical astroparticle physics
Gravitational wave detection
Physics in deep
underground
laboratories
Transnational access
Network of direct dark matter detection
Network of double beta decay
Network of deep underground science laboratories
R&D on double beta decay
R&D on low background techniques
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ILIAS at the LSM
Transnational access : Radon facility installed by Czech collaborators
Network : First meeting Sep. 2004, Edinburgh. Next meeting January 2005 at LSM.
Actual visits to the different labs will allow a better knowledge of working conditions
and specificities of the different sites.
R&D :
• Construction of a new ultra-low
background Ge detector (400 cc).
Prospective construction materials
are being measured. Monte Carlo
simulations are performed to get the
distinct contribution to the
background from the assembly
materials.
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Low radioactivity at LSM
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ILIAS at the LSM
R&D :
• Coordination of working package on RADIOPURITY OF MATERIALS.
First goal : database with measurements from experiments in the different
labs.
The database will serve as a guide and will give benchmarks on attained
radioactivity levels. Measurement of all materials involved in any
low-background set-up are, nevertheless, necessary.
We plan to include in the database a clear reference to the material provider
(and Ref. or lot number when available).
The aim in the longer term is to develop methods and techniques to obtain
materials extremely free from radioactive impurities.
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Low radioactivity at LSM
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