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Irradiation Goals

Irradiation Goals. Confirm that the breakdown performance improves with dose-Done Check that breakdown does not appear after inversion on n-type sensors-Done Confirm I bias , V dep changes as expected for proton/neutron irradiation

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Irradiation Goals

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  1. Irradiation Goals • Confirm that the breakdown performance improves with dose-Done • Check that breakdown does not appear after inversion on n-type sensors-Done • Confirm Ibias, Vdep changes as expected for proton/neutron irradiation • Test CCE, resolution, etc. performance after proton irradiation with pixel telescope

  2. Proton Irradiation Phi Sensors R Sensors • Irradiated 2 sets (n-type,p-type) of phi sensors and R sensors • Phi sensor: 1.47x1015 p/cm2 → 9x1014 niel/cm2 (7 years @ 8mm) • R sensor: 1.4x1015 p/cm2 → 8.5x1014 niel/cm2 (6.6 years @ 8mm) • Built 1 set into double-R and double-Phi modules for FNAL test beam and laser test • Other set used for CV measurements

  3. N-type R Sensor CV After 30 min@60 C equiv. 11 day@20 C Dep V:~560 V With no annealing, it is difficult to say if part depletes. The three clear kinks in the CV correspond to unirradiated left , partly irradiated middle, and fully irradiated right of sensor. So annealed to lower depletion point.

  4. P-type R Sensor CV After 30 min@60 C equiv. 11 day@20 C Dep V:~530 V With no annealing, it is difficult to say if part depletes. The three clear kinks in the CV correspond to unirradiated left , partly irradiated middle, and fully irradiated right of sensor. So annealed to lower depletion point.

  5. Laser Test-Proton Irradiation N-type Irr N-type non-Irr • Laser tested double-R and double-phi modules while cooled (~-7 C at sensor) • Stability of laser focus, intensity difficult to control • See similar fraction (Irr/Non-Irr) of charge in both p-type and n-type • Somewhere between 50-70% • 8.5x1014 niel/cm2 • From previous proton irradiaton on minis expect 40% (1.8x1015 niel/cm2) 68% (6.6x1014 niel/cm2) • With annealing to minima, expect 10-15% more charge collected • Will try to anneal during FNAL test-beam P-type non-Irr P-type Irr

  6. Proton Irradiation Conclusions • From RD48 damage constants, expect ~480 V depletion voltages after annealing for measured dose of proton for n-type and p-type silicon • We measured somewhere between 530-560 V for the n-type and p-type • From previous proton irradiations of n-in-p minis, we expect to collect ~60% of the max charge • From laser, get 50-70% pre-annealing • Will confirm with test beam • Thus, I would expect modules to be fully efficient after this dose (6.6 years @ 8 mm)

  7. Irradiation Results-IV P-type 5x1013 /cm2 1.5x1014 /cm2 N-type 1.5x1014 /cm2 1.5x1014 /cm2

  8. Low dose (~4-5x10-13 neq/cm2, expected 5x10-13 neq/cm2) High dose (~1.3-1.6x10-14 neq/cm2, expected 1.5x10-14 neq/cm2) Error dominated by uncertainty in annealing time

  9. Neutron Irradiation Results-CV P-type VdepPre=81V VdepPost=167 V DVdep=86 V VdepPre=81V VdepPost=393 V DVdep=312 V 5x1013/cm2 1.5x1014/cm2 N-type VdepPre=21V VdepPost=299 V DVdep=320 V VdepPre=25V VdepPost=277 V DVdep=302 V 1.5x1014 /cm2 1.5x1014/cm2

  10. Irradiation of ~136 kRads with 6 MeV photons Hard breakdown behaviour improved greatly due to radiation Charge in oxide Soft breakdown behaviour (semi-ohmic) improved only in 1 of 3 sensors (2 unchanged) Should improve with neutron/proton irradiation which causes more bulk damage Irradiation with neutrons at Ljubljaba Breakdown behaviour gone P-type and n-type IV similar after doses For neutron irradiation, p-type sensors have higher Vdep 390 vs. 280-300 after 1.5x1014 neq/cm2 Expect Vdep to be similar for n and p-type sensors with ~1014 neq/cm2 proton irradiations Changes in depletion voltages close to expected: From TDR, 1.3x1014neq/cm2 in 5 month LHC dose: DVdep=250 V Scaling for 5x1013neq/cm2, measured DVdep=86 V, expected DVdep=96 V Scaling for 1.5x1014neq/cm2, measured DVdep=302-320 V, expected DVdep=288 V Differences between measured and expected may be due to annealing Irradiation Results

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