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