Outline  WG2 (bank of pure isotopes)  WG3 (theory)  WG3 (Neodimium project - preliminary tests on Nd crystals)  WG4 (cosmogenics - code survey - exposure at accelerators)  WG5 (crystals - Pt effect in TeO 2 crystals)  WG6 (surface radioactivity - surface sensitive detectors)  WG7 (Ge in liquid nitrogen - first survey on adsorbers) Network N4 Joint Research Activity JRA2 Paris – 4 th October 2004 ILIAS Executive Board meeting Status of the DBD activity Andrea Giuliani

NETWORK – N4 Double Beta Decay searches

N4-WG2: bank of pure isotopes (strictly connected with JRA2-I1 “Isotope Enrichment”) NOW  working group formed  active contacts with Russian labs, in particular for 82 Se E. Previtali

Isotope separation is important not only for fundamental science, but also for  radio-medicine  agriculture  atomic power industry Evaluate the feasibility of a European project dedicated to the realization of a large set-up for isotope separation (the only way to produce 150 Nd, 48 Ca in reasonable amounts) formation of a working group on this specific aspect: Ezio Previtali Piero Benetti Pierre Louvet Serge Jullian Dominique Lalanne  first contact in Como (IDEA-NW kick-off meeting)  seminar by P. Louvet in Milano on last 1 st October N4-WG2: Bank of pure isotopes Explore the possibility to realize a large machine for isotope separation in plasma by ion-cyclotron resonance method www1.jinr.ru/Pepan/v-32-4/v pdf

N4-WG3: theory NOW  working group formed  work in progress  IDEA-NW meeting - Heidelberg Oct J. Suhonen Theoretical sub-meeting in Heidelberg 1.Jouni Suhonen, Jyvaskyla: “Open problems in Nuclear Matrix Element (NME) calculations of double beta decay rates” 2.Amand Faessler, Tuebingen: " Test of physics beyond the Standard Model and Reliability of the Nuclear Matrix Elements in the neutrinoless double beta dacay" 3.Vadim Rodin, Tuebingen: "The Pauli Principle and the Ikeda Sum Rule in the beta beta decay“ Etienne Caurier and Frederik Nowacki were also invited A summary on this sub-meeting will be the first deliverable The experimentalists will pose the following provocative questions:  can we learn more than just neutrino is a Majorana particle and have also useful quantitative information on the effective mass?  how to treat theoretical errors?  is it meaningful to consider all calculations for NME for a given nuclide and treat them as an estimate of the uncertainties on that nuclide?  which realistic experiments can be carried out to test theoretical models?  main topic of this task  can the theorists develop a common recommendation, in the framework of a general agreement among the various schools, on how to use NME (NME white book) ? establish contacts with N6

JOINT RESEARCH ACTIVITY JRA2 - “IDEA”

JRA2-P2: 150 Nd project Objectives :  Realization of a NdF 3 bolometer (requires substantial R&D work)  Realization of a bolometer based on NdGaO 3 or on compounds with a similar magnetic ordering  Development and test of small scale Nd-based bolometers  Study of the background in Nd-based bolometers, in case of success in the previous items Leading contractor: INFN Comments:  “high risk” task  nobody knows if a Nd-based bolometer can work  in the first year we should have a definite answer what to do in case of failure?  result affects selection of isotopes in task “Isotope Enrichment” S. Pirro

NOW  confirmation of NdF 3 and NdGaO 3 as promising candidates  study in progress of lasing crystals procurement of two NdGaO 3 sample crystals 1.13 x 13 x 13 mm 2.30 x 30 x 30 mm growth under care of South Carolina University procurement of one NdF 3 sample crystal 1.30 x 10 x 10 mm  2 holders designed  2 detectors prepared  special thermistors with higher resistances and sensitivities have been prepared at LBNL  they will be characterized in the next months

JRA2-B1: Cosmogenic induced activity Objectives :  Development and upgrade of the cosmogenic activation codes  Study of particular Ge detectors with a well known “cosmogenic history”  New experiments based on irradiation of Ge and TeO 2 samples with high energy protons at accelerators  Analysis of the irradiation results to check/upgrade activation codes Leading contractors: Zaragoza / INFN Comments:  well defined, “low risk” task  coordination with JRA1 is required S. Cebrian / M. Pavan

NOW Different libraries based on experimental and/or calculated data (EXFOR, MENDL, RNAL...) as well as individual references have been screened concluding that there are scarce data on the production of isotopes of interest for DBD, like 60 Co in TeO 2 or Ge and 68 Ge/ 68 Ga in Ge, and that results from different sources are not always in good agreement. Detailed technical report available in the IDEA web site. The analysis of existing codes is being carried out. The properties for cosmogenic studies of codes based on semi-empirical formulas and general-purpose MC packages like GEANT4 and FLUKA have been extensively analyzed and other MC codes specific for hadronic interactions are being taken into consideration The study of particular problems making a cross-check of different calculations and measurements (when possible) has started. Some applications using the most suitable of the analyzed codes are being developed to estimate the cosmogenic activation in TeO 2 crystals We have already performed irradiation experiments  1.85 and 5 GeV p at LBNL (USA) – on Te and Ge  24 GeV p at CERN – on Te Anaysis and comparison with predictions in progress establish contacts with JRA1

JRA2-B2: Underground crystal growth Objectives :  Crystallization of TeO 2 in radio-clean conditions, by eliminating radioactivity coming from crucibles and other elements  Feasibility study of underground Ge crystallization plant (LSC)  Feasibility study of underground TeO 2 crystallization plant (LNGS)  Realization of underground test crystallization plants (in the event of positive outcomes of the previous studies and of positive issues of cost negotiations with the companies specialized in crystallization) Leading contractors: INFN / Zaragoza Comments:  strong connection with “Cosmogenic Induced Activity” task  it is unlikely that funds are enough for test crystallization plants A. Giuliani / J. Morales

NOW contact with company Canberra – Eurosys established steps to check for a radio-clean crystal:  gamma-count metallic Te  check oxidation procedure  gamma-count TeO 2 powder  check crucibles  check materials for crystal cut and surface treatment  check bulk and surface activity of the crystal present crucible material: Pt it is a serious problem for two reasons: 1.alpha contamination in 190 Pt (~3.3 MeV) 2.modification of signal shape

JRA2-B2: the Pt problem in TeO 2 crystals CUORICINO background spectrum alpha region – 190 Pt peak – risk: low energy tail 1. effects on the pulse shape High Pt conc. 7 x 10 –7 g/g low Pt conc. 8 x 10 –9 g/g 2. “We have discussed on Iridium crucible issue. However, due to the brittleness of the Iridium, it's not easy to make the crucible for our Bridgman crystal growth. Answers from SICCAS (Chinese crystal company) To decrease the Pt contamination, we would like to make some modifications 1.use quartz crucible instead of Pt crucible for powder preparation 2.use low temperature in-gradient method to grow the crystal To make the experiement, we would need your funding of USD50,000 and in return we'll deliver you two pcs of 5x5x5 size crystals within three months.” [from SICCAS] We have contacted two American companies which use Czochralski instead that Bridgman  less interference between crucible and crystal 1.INTEGRATED PHOTONICS INC. (IPI), HILLSBOROUGH, NJ USA 2.CRYSTAL TECHNOLOGY INC., PALO ALTO, CA USA We have already procured a 35 x 35 x 30 mm TeO 2 crystal from CT  gamma-counted to check radio-purity  within end of the year: bolometric operation

JRA2-B2: modification of 1st year milestone / deliverable Definition of new materials for crucible construction in TeO 2 crystal growth MILESTONE Definition of new materials for crucible construction and/or of new crystallization techniques aiming at reducing the Pt effect in TeO 2 crystals

Technical table reporting alternative materials for crucible construction in TeO 2 crystal growth DELIVERABLE Technical report about new materials for crucible construction and about the application of the Czochralski technique to TeO 2 crystal growth JRA2-B2: modification of 1st year milestone / deliverable

JRA2-B3: Rejection of surface radioactivity Objectives :  very critical task: the CUORE success depends on the success of this task O. Cremonesi  Implementation of various surface analysis methods  Implementation of various surface cleaning procedures  Realisation of surface sensitive prototype bolometers  Development of CUORE-like modules with foreseen reduction of surface radioactivity by a factor between 10 and 100 with respect to present CUORICINO modules Comment: Leading contractor: INFN Surface radioactivity is in fact one of the worst sources of background in double beta decay experiments based on bolometers. Surface alphas are particularly dangerous continuous background spanning the region from threshold to few MeV

NOW Sensitivities in U and Th of the order of g/g can be obtained with the best HR-ICPMS devices. Laser ablation was abandoned after a clear evidence for non-uniformities in measurements carried out in Canada thickness (  m) 27 Cu concentration (ppb) U and Th surface contamination measurements on test Cu samples (cleaned as Cu used in CUORICINO) performed at ISPRA with HR-ICPMS INFN – Milano assigned an old but perfectly working dilution refrigerator to the specific development of surface sensitive bolometers, installed in the cryogenics lab of the Insubria University (Como) Base temperature: 13 mK Cooling power: 25  W at 100 mK thin auxiliary bolometers shield the main crystal, being thermally connected to it and providing full coverage

JRA2-B4: Ge diodes in liquid nitrogen Objectives:  Study of adsorption materials, especially for Kr and other potential contaminants  Upgrade of the potential of the existing nitrogen (gas) purification plant (which is housed in LNGS) in order to serve a large self-shielding liquid nitrogen tank  Test operation of Ge diodes in purified nitrogen Leading contractor: MPI Heidelberg Comment:  task with a well defined self-consistent program S. Schönert not only LN2, but also LAr (active shield)

NOW Theoretical studies The retention ability of adsorbers depends strongly on the distribution of its pores. Investigation was performed of the binding energy of different gas particles in pores of different sizes (simple model based on Van der Waals forces). Preferred non-polar adsorbers Trace compo nent Best pore size (carbon based adsorbers) Ar6.8 Å Kr7.0 Å Rn~ 8 Å Trace compo nent Best pore size (carbon based adsorbers) Ar6.8 Å Kr7.0 Å Rn~ 8 Å negligible internal polarity dedicated pore size distribution hydrophobic zeolites Adsorber Manuf acturer Main characteristics Hydrophobic zeolite MFI- type Zeoch em Very low internal polarity, pores ~5.3 Å Hydrophobic zeolite BEA- type Südch emie Slightly larger internal polarity, pores ~6.6 Å Synthetic carbon F3/F4 Carbo Act Low 222Rn emanation rate Carbon Cloth FM Charc oal Cloth Fabric (no grains) Activated carbon C 38/2 Carbo Tech Optimized pores for solvent recovery

Meetings and connections for IDEA General meeting: every SIX months (merged with NW meeting)  Check of the milestone achievements  Set of future milestones  Scientific discussion  Kick-off meeting: 8 April 2004, Como (I)  Next general meeting: October 2004, Heidelberg (D) THREE months after each general meeting: “middle term deadline”  Advancement reports of the task leaders (put on the WEB site  see July 2004 reports)  General report of the coordinator on the basis of the task advancement report  Next middle term deadline: 15th January 2005 Sub-meetings of the working groups when necessary, keeping the coordinator informed of their occurence  3 meetings of WG1 and WG2  1 meeting of WG5  2 meetings of WG6 AGENDA – IDEA-NW Kick-off Meeting – 8 th April 2004, Como (Italy) 9:30 A. Giuliani [30'] Introduction to IDEA 10:05D. Lalanne [15']Introduction to DBD-Nw 10:25B. Saghai [15']Double Beta Decay in ILIAS 10:45coffee break 11:15 F. Piquemal [15']Coordination of DBD searches 11:35E. Previtali [15'] Bank of pure isotopes 11:55V. Rodin [15']Double Beta Decay and Nuclear Structure 12:30Lunch Break 14:00S. Jullian [15']Isotope enrichment & Se-82 project 14:15 [30']discussion on isotope enrichment 14:45O. Cremonesi [15'] Rejection of surface radioactivity 15:05S. Pirro [15']Nd-150 project 15:30coffee break 16:00S. Cebrian [15']Cosmogenic induced activity 16:20A. Giuliani [15']Underground crystal growth 16:40S. Schoenert [15'] Operation of Ge-diodes in LN2 17:00A. Giuliani [15']Conclusions

no information ! Financial issues money “lost” !! no money spent “...wrangling with the administration...” no money spent up to now plan:  consumable (for low temperature tests of bolometric elements for Nd and surface sensitive detectors)  travels 437,52 spent for travel ~ 2000 to be spent for travel So far only travel costs out of the budget. Major spending will start soon: postdoc for task B4 –WG7. Until April 05 about will be spent placed order  21000: special crystals for studies on surface radioactivity planned  10000: LHe for tests on Nd bolometers surface sensitive detectors and CZ-grown crystals  5000: travel to visit US companies producing CZ-grown crystals  2000: Cu samples  8000: consumable for ICPMS measurements  16248: 3 post-docs (3 months each: Jan – Feb – March)  5000: travels for meeting  25000: under discussion  18382: overheads CONTRACTOR I YEAR EU contribution CNRS INFN Zaragoza Bratislava 2440 Jyvaeskylae 2440 MPI Tuebingen 2440 Leiden Praha 2440 London 3050 total