Surface measurements with CYRIC irradiated ATLAS12 samples

1. Surface measurements with CYRIC irradiated ATLAS12 samples Hartmut F.-W. Sadrozinski, VitaliyFadeyev,Kevin To Zachary Galloway,Zhijun Liang SCIPP, UCSC

2. Reminder of Birmingham samples measurements in UCSC • Birmingham samples • ATLAS12A samples irradiated with protons at Birmingham by 27MeV protons • 8 fluences : 1e12, 5e12,1e13,1e14,1e15,2e15,5e15 Neq/cm2 • Zones : BZ3C and BZ3F • There is some discrepancy of R_INT in proton radiated sample in different zones ( BZ3C , BZ3F) • Try to annealed BZ3C (1e14) sensor to see the impact of annealing. • Annealed BZ3C (1e14) sensors in 80°C for two hours

3. New CYRIC samples • Thanks to Yoshinobu and his colleagues • Irradiated Samples at CYRIC have been sent to UCSC. • irradiated with 70MeV Proton beam • 4 sets of (ATLAS07, ATLAS12A, ATLAS12M) BZ3’s per fluence • 5 fluences: 1.13, 4.88, 10.6, 20.6, 114(*) x 1014 neq/cm2

4. CYRIC samples : I-V curve • ATLAS12A, ATLAS 12M and ATLAS07 sensors irradiated at CYRIC shows similar leakage current. • Less sample dependence variation F=1e15 Neq Temperature = -10°C

5. CYRIC VS Birmingham samples:leakage current • Birmingham irradiated samples shows large variation in leakage current F=1e15 Neq Temperature = -10°C

6. CYRIC samples : Inter-strip resistance VS bias voltage • Large Inter-strip resistance for samples irradiated by CYRIC • >100 Mohm at 400V bias voltage at 1E15 Neq • >10 times better than ATLAS12 specification • Small samples dependence variations • The difference between CYRIC ATLAS12A/ATLAS12M/ATLAS07 is small F=1e15 Neq Temperature = -10°C

7. CYRIC VS Birmingham samples:inter-strip resistance • Large Inter-strip resistance for samples irradiated by CYRIC • 2~3 order larger than that of in Birmingham samples RINT (Ohm) F=1e15 Neq Temperature = -10°C Bias Voltage (V)

8. Part II Correlations study • We try to summarize the dependence of inter-strip resistance of irradiated sensors. • As a function of bulk leakage currents • As a function on Ionising Dose (TID) .

9. Correlations between leakage currents and inter-strip resistance • leakage currents and inter-strip resistance • At 6 different temperature (10°C, 5°C, 0°C, -5°C,-10°C,-15°C) • One temperature per data point • Using different irradiated samples • Both gamma and protons irradiated samples included • leakage currents and inter-strip resistance • Linear correlations found in log scale plot

10. inter-strip resistance VS Ionising Dose (TID) • Plots dependence of R_INT dependence on TID • For both Gamma and proton irradiated sampes • For Birmingham sample (proton beam at 27MeV) • F=1e15 Neq -> TID = 119 MRad. • F=1e14 Neq -> TID = 11.9 MRad. • F=1e13 Neq -> TID = 1.9 MRad. • For CYRIC sample (70 MeV proton beam) • F=1e15 Neq  TID ~ 70 MRad. Temperature = -15°C

11. Summary • UCSC group have started the study of CYRIC sample. • First result for F=1e15 Neq proton irradiated samples shows that • CYRIC sample has a much higher inter-strip resistance ( >100 M Ohm) • Lower leakage current • Less sample to sample variation in inter-strip resistance and leakage current • The correlations between leakage currents and inter-strip resistance • Linear dependence found in double log scale plot • These dependence seems to apply for both gamma and proton irradiated sample • The correlations between Ionising dose (TID) and inter-strip resistance has been studied. • Next step • We will measure all the CYRIC samples at different fluences for next meetings. • Aim to getting the final measurements in next 1~2 months • Will wrap up our contribution to Marcela’s talk in Hiroshima