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

1. Delivery of 15 kg nat Ge
2. Status of enrichment 76Ge
3. Purification 76GeO2?76Ge (6N)
4. Crystal production
5. Detector production
6. 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

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• 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.

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• 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 ?)