JRA2 - IDEA Zaragoza, Andrea Giuliani University of Insubria (Como) and INFN - Milano

IDEA: presentation of the tasks  I1 - Isotope enrichment  P Se project  P Nd project  B1 - Cosmogenic induced activity  B2 - Underground crystal growth  B3 - Rejection of surface radioactivity  B4 - Ge diodes in liquid nitrogen promising nuclides background control

Milestones/deliverables to be achieved within 31/3/2006

Financial situation requested prefinancing for second 18 months [Apr Sept 2006] and expenses in [Apr Sept 2005] CNRSINFNUNIZARCTUJYUMPIKEKUTMiniGRAILFMFI-UKUCLIRMM requested- prefinancing direct costs personnel equipment consumable travel total ratio (%) total/prefin (d.c.)

B2 – Underground crystal growth New contractor: IRMM

B2 – Ge crystal growth IRMM (Geel) New contractor UMICORE (Olen) Largest producer of Ge in the world CANBERRA (Olen) Company specialized in semiconductor detector development HADES (Mol) uderground lab (230 m of rock) steps for Ge detector realization: 1. reduction of GeO 2 (10 ppb impurities) 2. poly- and mono-zone refinement (1 and 0.01 ppb) 3. pulling (0.001 ppb) 4. diode fabrication crystal growth in principle, all the steps can be made underground in practice, too expensive good alternative: minimize CR exposure between steps

CANBERRA UMICOR IRMM HADES ~ 10 km B2 – Ge crystal growth

B2 – TeO 2 crystal growth 4 detectors from CTI with final CUORE size will be ready in Feb 2006 They will be operated in a clean environment after surface treatment Recent effort  to study the possibility of replacing Bridgman method (SICCAS) with Czochralski method (CTI, IPI) get rid of Pt impurities from the crucible ( 190 Pt is radioactive) A 3x3x3 cm crystal procured from CTI company The crystal was operated as a detector for two runs in Gran Sasso (Hall C refrigerator - R&D for DBD bolometers) The technical bolometric performance was excellent High surface radioactivity  not possible to set meaningful limits on the bulk impurities (U, Th, Pt)

B2 - R&D Contract between LLNL and CTI  Phase 1 : Redesign of CTI furnace to grow 75 mm diameter TeO 2 crystals (completed)  Phase 2:Production of one TeO 2 crystal large enough for 5x5x5 cm cube (target date: 30/9 – 31/12)  Phase 3:Delivery of 4 each 5x5x5 cm finished TeO 2 crystals (target date: 31/12/05 – 31/3/06)  Phase 4 : Successful test of 5x5x5 cm TeO 2 crystals as bolometers at LNGS (within 10 weeks of delivery) Important stimulus from IDEA: - visit to CTI company and preliminary agreement - discussion on crystallization procedure - purchase of a 3x3x3 cm 3 crystal

Need to work with them to develop clean procedures for crystal production  clean materials  strict procedures  clean room operation Visit planned for Nov. 14  prepared list of topics to be discussed  tour new production facility B2 - SICCAS (Shanghai) option

B2 - SICCAS (Shanghai) discussion plan

Web site in progress