1. Gusev Konstantin, Kurchatov Institute / JINR 09.11.2005, Gerda meeting Some technical aspects of testing and adaptation of existing detectors

2. Gusev Konstantin, Kurchatov Institute / JINR 09.11.2005, Gerda meeting Preparation of adaptation consists of: I. Testing of existing enriched detectors; II. Repairing of detector performance in the actual cryostats, if it will be needed; III. Estimation of the risks of crystal repacking procedures and Careful check of all necessary operation with typical non- enriched detectors.

3. Gusev Konstantin, Kurchatov Institute / JINR 09.11.2005, Gerda meeting Detector 1Detector 2Detector 3Detector 4Detector 5 Full mass, kG 0.982.9062.4462.42.781 Depletion voltage, V 3000320029001900 Bias voltage, V (recommended) 4000 35002500 FWHM, keV at 1332 keV (specifications) 1.981.911.972.06 FWHM, keV at full HdMo Set-up 2.222.432.712.142.55 Test at February 2005 FWHM, keV at 1332 keV 2.72.272.532.352.75 Test at May 2005 Bias voltage, V 37004000 35002500 FWHM, keV at 1332 keV 2.882.53.02.763.05 TESTING OF EXISTING DETECTORS

4. Gusev Konstantin, Kurchatov Institute / JINR 09.11.2005, Gerda meeting TESTING OF EXISTING DETECTORS For best realization we need: 1.Spectrometric channel with the best performance; 1.Precision pulse generator; 2.Model of PA first stage.

5. Gusev Konstantin, Kurchatov Institute / JINR 09.11.2005, Gerda meeting REPAIRING OF DETECTOR PERFORMANCE For heat and pump procedures we must have: 1.Turbo molecular pump with enough efficiency; 2.Nitrogen traps for elimination of any contaminations of detector; 3.Valve for connecting between pump and detector cryostat; 4.Absolutely clear or new vacuum elements (rings, fillers, etc.); 5.Heater, maybe electric fan (temperature not higher than 150°C).

6. Gusev Konstantin, Kurchatov Institute / JINR 09.11.2005, Gerda meeting POSSIBLE RISKS  Contamination of detector surface because of too early opening of cryostat.  Damage of implantation layer due to careless dismounting of diode from existing support or packing it into the new holder.  Damage of crystal because of too strong pressure in the new support.  Damage of crystal due to thermal shock.  Damage because of keeping and transportation of naked diodes in non- adequate conditions.  Deterioration of lithium layer after too long staying of detectors at room temperature.

7. Gusev Konstantin, Kurchatov Institute / JINR 09.11.2005, Gerda meeting Conclusions I. Testing of all existing detectors. II. Repairing of detector performance inside the actual cryostats. Required time for I and II is about one month at best. III. For elimination of estimated risks when we open cryostats: Special tools for accurate repacking must be ready; Leak proof box for crystals keeping must be ready too ; All adaptation procedures at non-enriched detectors must be realized.