1. TG 11 overview - Material screening - Hardy Simgen MPI für Kernphysik Heidelberg

2. Outline Gamma-ray screening Radon: Online monitoring Behaviour of Rn and Rn daughters Emanation measurements Hardware: New gas counting system at LNGS New Germanium spectrometer for MPIK

3. Gamma-ray screening results Activities in [mBq/kg] Sample 226 Ra 228 Th 228 Ra 40 K Sticky tape (TESA)<60<140<100<440 Mineral oil 6  29  2 <15 44  20 Silicone gel<40<6<12 60  36 Polyurethane (black) 6500  4003900  4004200  40026500  3400 PMT cable 180  30 <130<160 560  230 Iglidur granulate Drylin <6.5<4.6<15 130  10 Foamable polystyrene 0.48  0.060.38  0.070.48  0.103.6  0.7 Graphite 1700  2002300  3002000  3002700  900

4. Gamma-ray screening Screening of PCB for PZ0  Matthias Laubenstein‘s talk

5. Behaviour of radon + radon daughters Work is proceeding in Cracow No update this time, but: „We are getting a clearer picture of Rn + Rn daughters in LN 2, but it is not yet complete“ (Marcin Wojcik). Further activity in preparation: Behaviour of Rn daughters on Ge discs

6. Radon monitor Ready for shipping  Jochen Schreiner‘s talk

7. 222 Rn emanation measurements Focus on cryostat and lock  Grzegorz Zuzel‘s talk

8. GNO shield for proportional counters

9. Ability to measure gaseous radioactive isotopes at Gran Sasso ( 222 Rn, 85 Kr, 37 Ar, 39 Ar, 133 Xe, 71 Ge,... ). On-site 222 Rn emanation measurements are now possible for small samples.

10. sample 250 damping-plate PMT 1“x1“ ≈ 2015 mm Airlock like GeMPI 2 and 3 sample Airtight glovebox system Plasticscintillator 2 plates 30 mm each Cu 50 mm Plasticsc 50 mm Pb 50 mm and more PE + BC 4 50 mm Cu-frame for block (existing) steel frame 529x529x750? Item- profil ≈ 1250 mm steel plate ≈ 1300

11. Ge sample airlock View from top sample- chamber open middle veto counter slided aside shielding-block lifted up and slides aside sample container are moved along rails Airtight glovebox system

13. time since Ra removal [y] rel. activity after Ra removal time since Ra removal [y] Disequilibrium in the Th decay chain From: A focused review of operations and thorium exposures at the Dow Chemical Company Madison Plant, Advisory Board on Radiation and Worker Health (S. Cohen and Associates,2007) G. H. GERDA collab. Meeting, Padova 11. -13. March 09

14. G5 G7 ∞ exposure age via 54 Mn time since Ra removal [y] rel. activity after Ra removal G. H. GERDA collab. Meeting, Padova 11. -13. March 09