Agenda

1. Agenda A. Caldwell overview 15' S. Belogurov Shielding against cosmogenic activation: current results and prospects 15' V. Kornoukhov Enrichment & purification 45' S. Nisi ICPMS test at LNGS on natGe samples 20' I. Abt status new detector design & prototypes 15' Joint meeting with TG10: K. Kroeninger simulation studies X. Liu test stands at MPI

2. Overview of Phase II Detector Activities Delivery of 15 kg nat Ge Status of enrichment 76Ge Purification 76GeO276Ge (6N) Crystal production Detector production Simulation studies

3. Delivery of 15 kg (nat)Ge from Krasnoyarsk Munich Special container to shield Ge from n,p 20 day trip. Very smooth no problems encountered

4. Shielding container restacked, returned to Siberia for transport of enriched 76Ge. Shielding calculations will be discussed by S. Belogurov. Samples delivered to LNGS for ICP-MS measurements. Presentation by S. Nisi

5. The 15 kg nat Ge is currently in storage at the TU Muenchen. We will transport it to the HADES facility in the near future. Currently consider transporting and storing the enriched material to the HADES facility also.

6. Procurement of 30 kg 76Ge: • as of two weeks ago, 17 kg enriched by ECP/Svetlana • the material is enriched in GeF4 form, then converted to GeO2 at ECP. It seems that reduction in purity happens in this series of steps (see talk by V. Kornoukhov) • GeO2 must then be transformed to Ge, purified. We currently anticipate that this will be done at the Germanyi plant. GeO2 GeCl4  Chemistry  GeO2 (6N)  Ge • Measurements of GeO2 from ECP as good as 4N. Experiment performed to see if can skip GeCl4 step+ chemistry and increase yield beyond 72 %. Report by V. Kornoukhov • We need to decide how to proceed on purification. Proposal to perform new experiment with 30 kg natGe to measure yield from standard process using material from ECP.

7. Crystal Production: • So far, we have assumed that crystal production would take place at Umicore. Initial discussions, visit in December 2004 were very positive. At that time, Umicore promised to make a proposal to us how to proceed by mid-January 2005. • scheme for crystal growing received in mid-April after repeated gaps in communication • there will be significant material losses (scraps from cutting, samples for testing, grinding losses). Still need to understand how much can be recovered • the material will stay above ground for significant time. First crystal - 12.7 days, second 26 days, third 41 days …

8. The problem ? • since then, no contact despite several attempts • concern - Umicore may not be interested in our business • at this time, we do not have an alternative to Umicore. Initial investigations found no firms in Russia. In U.S., Ortec & Canberra/Tennelec/Oak Ridge in principle options

9. Detector production/simulations: • We have performed detailed MC studies of background rejection in segmented detectors. Talk by K. Kroeninger in MC session. • 5 test detectors have been ordered, 2 with the expected 18-fold segmentation. Detailed discussions with Canberra/Eurysis on contacts, supports, … To date, 2 detectors delivered, third is ready. Talk by I. Abt. • Test facilities set up at the MPI for the different types of detectors (p-type, n-type). Calibration sources in hand, first tests underway … Talk by X. Liu in MC session.

10. Discussion items: • We have several MS measurements from various steps in the procedure (as will be shown by Vasily). We need to discuss further test (LNGS ?, which samples) • - how to document quality test information • - documentation of exposure of material • time schedules for different steps/critical points. To be decided very soon - purification scheme for material. • storage location of the material (HADES, LNGS ?)