Low radioactivity at the Modane Underground Laboratory

Pia LoaizaLaboratoire Souterrain de Modane, France

LRT 2004 12-13 Dec. 2004, Sudbury, Canada

LRT2004 Low radioactivity at LSM Pia Loaiza

LABORATOIRE SOUTERRAIN DE MODANE

FRANCE ITALIE

AltitudesDistances

1228 m 1298 m1263 m0 m 6210 m 12 868 m

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.

LRT2004 Low radioactivity at LSM 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 themid-point of the Fréjus road tunnel

LRT2004 Low radioactivity at LSM Pia Loaiza

PEOPLE AT LSM

LRT2004 Low radioactivity at LSM Pia Loaiza

EDELWEISS IIFrench 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

EDELWEISS : Dark matter WIMP search

EDELWEISS I exclusion limits present

EDELWEISS II sensitivity goal

LRT2004 Low radioactivity at LSM Pia Loaiza

NEMO 3 : Neutrinoless double beta decay

NEMO 3 collaboration : France, Czech Republic, USA,Russia, Japan, Great Britain

August 2001 Start taking data February 2003

wood

coil

Iron shield

Water tank

May 2004

May 2004 : Radon purification system.

Tent surrounding the detector

LRT2004 Low radioactivity at LSM Pia Loaiza

Sample(Os-500 g)

3He-countersNeutronmoderator

Super Heavy elements In

Nature

TGV-2 : CSNSM-Dubna

10 g of 48Ca for 2

10 g of 106Cd for ECEC

Radon trapping facility

Installation September 2004

LRT2004 Low radioactivity at LSM Pia Loaiza

Radon trapping facility

Time during which radon is trappedin the « filter » : Tr = K(T) M / Q

K(T) : dynamic adsorption coeff.M : charcoal massQ : Air rate

2 charcoal towers : T1 = -53 C, T2 = -45 CM = 2 x 450 kg

Vol. clean air : 125 m3/hActivity 222Rn = 15 mBq/m3

Radon purification by adsorption in charcoal

LRT2004 Low radioactivity at LSM Pia Loaiza

Ge detectors at LSM

13 germanium detectors to measure low radioactivity levels

LRT2004 Low radioactivity at LSM Pia Loaiza

Ge detectors at LSMApplications :

• 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.

LRT2004 Low radioactivity at LSM Pia Loaiza

7Be and 137Cs concentration in the atmosphere

Ge detectors at LSMApplications :

Bordeaux wine datingThe concentration of 137Csprovides a simple method to estimate the wine age.

Monitoring of radioactive contamination in the atmosphere

Measurements of artificial radionuclides in certainsamples require very low backgrounds. Those measurements are carried out at the LSM.

LRT2004 Low radioactivity at LSM Pia Loaiza

Ge detectors at LSM Detector 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

LRT2004 Low radioactivity at LSM Pia Loaiza

ILIAS : Integrated Large Infrastructures for Astroparticle Science

ILIAS is an initiative proposed for funding by the European Union.

Network of direct dark matter detection

Network of double beta decay

ILIAS

Physics in deep underground laboratories

R&D on low background techniques

Theoretical astroparticle physics

Gravitational wave detection

Transnational access

Network of deep underground science laboratories

R&D on double beta decay

LRT2004 Low radioactivity at LSM Pia Loaiza

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.

LRT2004 Low radioactivity at LSM Pia Loaiza

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.