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October 6-7, 2007FCAL Collaboration Meeting3 Poly- and single crystalline CVD diamond samples CVD diamond samples scCVD diamond area 5x5 mm 2, thickness 340 µm, metallization Ø3mm pCVD diamonds active area 10x10 mm 2, Ti-Pt-Au metallization thickness 500 µm
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Investigation of CVD Diamonds Investigation of CVD Diamonds as Sensor Material for BeamCalas Sensor Material for BeamCal
Alexandr IgnatenkoAlexandr Ignatenko
FCAL Collaboration Meeting, OrsayOctober 6-7, 2007
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 22
OverviewOverview Poly- and single crystalline CVD diamond samplesPoly- and single crystalline CVD diamond samples pCVD diamonds investigationpCVD diamonds investigation
Results from testbeam’06Results from testbeam’06Results from testbeam’07Results from testbeam’07
scCVD diamond investigationscCVD diamond investigationResults from testbeam’07Results from testbeam’07Initial polarization studiesInitial polarization studies
SummarySummary
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 33
Poly- and single crystalline CVD Poly- and single crystalline CVD diamond samples CVD diamond diamond samples CVD diamond
samplessamples
scCVD diamondarea 5x5 mm2, thickness 340 µm,
metallization Ø3mm
pCVD diamonds active area 10x10 mm2,
Ti-Pt-Au metallizationthickness 500 µm
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 44
pCVD diamonds investigationpCVD diamonds investigation
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 55
Results from testbeam’06Results from testbeam’06
Rather similar behavior: first pumping, then CCD decrease
pCVD diamonds investigationpCVD diamonds investigation
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 66
The CCD decreased after the irradiation
Recovers at small doserates
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 77
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 88
Results from testbeam’07Results from testbeam’07
Similar behavior: first pumping, then the CCD decreases
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 99
Before irradiation
After irradiation before UV illumination
After irradiation, UV illuminated
Value used at testbeam
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 1010
Before irradiation
After irradiation before UV illumination
After irradiation, UV illuminated
Revealed the CCD larger than that before irradiation
Value used at testbeam
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 1111
Before
Before
After
After
I-V characteristics
No significant increase of currents
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 1212
scCVD diamond investigationscCVD diamond investigation
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 1313
Results from testbeam’07Results from testbeam’07
100% efficient
scCVD diamond investigationscCVD diamond investigation
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 1414
Before irradiation
After irradiation
Value used at testbeam
Time dependence
Small CCD increase
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 1515
Initial polarization studiesInitial polarization studies
0 V
0 V
0 V
-0.3 V
Box with the sample rotated 900
Reverse connection to the PA
Direct connection to the PA
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 1616
0 V
-1 V
-4 V
-16 V
-7 V
Direct connection to the PA
2 peaks can be observed
Ratio of their heights changes with bias voltage
Spectrum made with oscilloscope to check the
ADC operation
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 1717
0 V
-2 V
-4 V
-6 V
-14 V
-25 V
Reverse connection to the PA
An indication to 2 peaks
October 6-7, 2007October 6-7, 2007 FCAL Collaboration MeetingFCAL Collaboration Meeting 1818
SummarySummary1. Both poly- and single crystalline CVD diamond sensors stood the
absorbed doses of several MGy and still were able to operate properly.
2. Values of CCD after irradiation being less than that before, increased after absorption additional (low) doses.
To be done:
1. Understand the mechanism of damage.
2. Clarify the dependence of CCD on dose, doserate and other factors.
3. Discuss with manufacturers the possibility to provide more radiation hard samples in future.
