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Irradiation with Protons - IQC Karlsruhe. IEKP - Universität Karlsruhe (TH). Isochroncyclotron in Karlsruhe. 26 MeV protons Frequency: ~33MeV Accessible within 2 days. Irradiation Area. Cooling with Nitrogen gas down to -50°C Initial positioning by laser pointer
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Irradiation with Protons -IQC Karlsruhe IEKP - Universität Karlsruhe (TH) 1.Irradiation Workshop - Karlsruhe
Isochroncyclotron in Karlsruhe • 26 MeV protons • Frequency: ~33MeV • Accessible within 2 days 1.Irradiation Workshop - Karlsruhe
Irradiation Area • Cooling with Nitrogen gas down to -50°C • Initial positioning by laser pointer • Scanning with 1mm row steps (10cm/s) • Used proton current: 2 mA • Irrad. of 120x120mm2 up to 1e14 p/cm2 takes 20min 1.Irradiation Workshop - Karlsruhe
During Irradiation ... Cold box with proton beam spot on mylar window Scanning speed up to 250 mm/s ! 1.Irradiation Workshop - Karlsruhe
Homogeneity of Scanning Scan Area Area of Interest Autoradiography picture 1.Irradiation Workshop - Karlsruhe
Fluence Estimation • Beam current I in p/s • Calculate ratio r of hits inside homogeneous area to total hits • F = I * r * t / Ahomogene • Get time t for irradiation • Adjust speed to have integer no. of scans Teststructure 1.Irradiation Workshop - Karlsruhe
Fluence Measurement • Ni foils behind teststructures in homogeneous area • Measure specific activity of 57Ni line with Ge-Spectrometer • Extrapolation to activity at 3.77 days after irrad.(T1/2 = 35.6h = 1.483 days t = 2.14 days) • Calibration factor for 26 MeV protons:19.28 kBq cm2 / mg mAh • 1 mAh = 22.5e15 protons 1.Irradiation Workshop - Karlsruhe
Comparision 1.Irradiation Workshop - Karlsruhe
Speed Calculation 1.Irradiation Workshop - Karlsruhe
Current Control • Beam current monitored during irradiation • Data saved to disk • On-line integration of current • Beam and scanning automatically stopped if current out of limit (e.g. 10%) • Insert aperture to get more stable low current 1.Irradiation Workshop - Karlsruhe
Biasing scheme • After 10 years LHC we expect a current of upto 1µA per strip at 1M 1V potential at p-implant • Bias of 1V during irrad. and both AC and biasring on ground gives 1V over diel. • Used bias voltage for safety reasons (voltage drop in power lines) : 12 V 1.Irradiation Workshop - Karlsruhe
Next Irradiations • Hybrid • Optohybrid • Module • We will provide the hybrids with power, clock, I2C-pulses and reset. • The module will be under bias. 1.Irradiation Workshop - Karlsruhe