43624321e61671fd555695b8cfb7f595.ppt
- Количество слайдов: 18
Ge Test-stands at MPI Munich Xiang Liu 1. General 2. Crystals, Test-stands & Results 3. Outlook
Crystals & Test-stands 2 Canberra crystals (for test-stands II & III) ØCanberra-I : non-true coaxial, no segment (ready & tested) ØCanberra-II: coaxial, 18 segments, 6 x 3 z 3 DSG crystals (for test-stands I & III) ØDSG-I : true coaxial, no segment (ready) ØDSG-II : 6 segments (ready) ØDSG-III: 18 segments, 6 x 3 z Gerda Collab. , Jun 27 -29, 2005 3 test-stands: üEurysis test-stand: for Canberra-I & II in LN 2 (ready) üMPI test-stand: for DSG I II & III in LN 2 (almost ready) üVacuum test-stand: for DSG & Canberra crystals (September) Page 2
Goal With Eurysis & DSG LN 2 Test-stands: ühandling Ge in LN 2 üGe Properties (resolution etc. with source) üSegmentations (coincidence cut for ) üPulse shapes (true & non-true coaxial) üMC verification (energy, pulse shape) With Vacuum Test-stand: üDead layer thickness (with laser) ü source Gerda Collab. , Jun 27 -29, 2005 Page 3
Crystals Canberra-I: non-true coaxial, no segment, mounted on stick crystal preamp Canberra-II: 6 x 3 z Gerda Collab. , Jun 27 -29, 2005 Page 4
Crystals Canberra-I Gerda Collab. , Jun 27 -29, 2005 Page 5
1 st Test-stand: Eurysis Test-stand üMade in Eurisys üFor Canberra crystals only üDewar ~50 cm H, ~20 cm R üHeater at top and bottom (to evaporate LN 2) üPlug & play Open for crystal heater Safety valve source Gas & LN 2 Canberra-I Gerda Collab. , Jun 27 -29, 2005 Eurysis Page 6
Eurysis Test-stand operation Steps: 1) Fill Dewer with LN 2. 2) Take Canberra-I out from vacuum can. 3) Dip Canberra-I into LN 2. 4) Apply HV and measure. Steps after measurement: 1) Seal dewer gastight. 2) Pump in gas N 2 and LN 2 out. 3) Turn on top & bottom heater. 4) Turn on heater around crystal for 2 hours. 5) Take out canberra-I and put back to can and make vacuum. No condensation on crystal during warmup. Gerda Collab. , Jun 27 -29, 2005 Canberra-I Eurysis Page 7
Results from Eurysis Test-stand Jun 7 th, 2005, Eurysis Test-stand with Canberra-I crystal. FWHM ~5 ke. V at 1. 173 Me. V, need more investigation. Gerda Collab. , Jun 27 -29, 2005 Page 8
Crystal DSG-I 3 Ge crystals from DSG: DSG-I : P-type, true-coaxial, no segment. Gerda Collab. , Jun 27 -29, 2005 Page 9
Crystals DSG-II & III DSG-II : P-type, true-coaxial, 6 phi segments (test at DSG done, now at Munich) DSG-III: 6 phi x 3 z Gerda Collab. , Jun 27 -29, 2005 Page 10
2 nd Test-stand: MPI Test-stand üSimilar to Eurysis, made in MPI üBigger dewer ~1 m H, 30 cm R üGallow loading crystals. üOnly for DSG I, II & III üSimilar operating procedure. Cover Hanging strings Crystal model Dewer Faraday cage Gerda Collab. , Jun 27 -29, 2005 Page 11
MPI Test-stand Operation Critical: no condensation on crystal during warm-up minimize time to remove LN 2 and warm up detector. Plan to use little heater. Expect the first result within 1 -2 weeks. Load crystal Gerda Collab. , Jun 27 -29, 2005 During operation Page 12
MPI vs. Eurysis Teststand vs. MPI test-stand has many advantages: ü closer to Gerda design (mini-Gerda), can test support strings & cable in LN 2. übuilt in house, easy to modify according to new requirement. üSupport strings flexible, can hang 2 crystals together and take coincidence data. üTest-stand built in house, cost “no” money. üIn principle, can dip Canberra crystal into MPI test-stand, & v. v. üSame physics tests Gerda Collab. , Jun 27 -29, 2005 Page 13
3 rd Test-stand: Vacuum Test-stand Vacuum tanks Gerda Collab. , Jun 27 -29, 2005 Page 14
Vacuum Test-stand ü 3 stations mounted together üSources move in 3 D around crystal üCrystal fixed & cooled through LN 2 pipes üFor both Canberra & DSG crystals ü , sources & laser can be used üExpect first run September Gerda Collab. , Jun 27 -29, 2005 Page 15
DAQ XIA Pixie-4. On board PC. Each card reads 4 channels. 14 bit ADC, 75 MHz spc. for pulse shape. PC Pixie card Gerda Collab. , Jun 27 -29, 2005 NIM cards for HV and preamp. power supply Page 16
Outlook Eurisys Test-stand: More study with Canberra-I, solve resolution problem. Canberra-II detector end of this year MPI Test-stand: DSG-I 1 -2 week. True coaxial, good for pulse shapes. DSG-II crystal ready, 1 -2 week, study segments and more pulse shapes. DSG-III arrive end of this year Vacuum Test-stand: Start data taking September Study dead layer with laser, hadronic interaction with sources. Gerda Collab. , Jun 27 -29, 2005 Page 17
Conclusion Many test stand setups: üDifferent crystals, non-true, true-coaxial, none, 6 & 18 segments. üDifferent environment, LN 2, Vacuum. üDifferent sources, , & laser Rich physics will be explored: ü Ge general properties. üEM & hadron interactions. üPulse shape. üAll with MC simulations. Any suggestions, ideas about measurement, simulation, please contact us! Gerda Collab. , Jun 27 -29, 2005 Page 18