158,196 research outputs found
Silicon Sensors for Trackers at High-Luminosity Environment
The planned upgrade of the LHC accelerator at CERN, namely the high
luminosity (HL) phase of the LHC (HL-LHC foreseen for 2023), will result in a
more intense radiation environment than the present tracking system was
designed for. The required upgrade of the all-silicon central trackers at the
ALICE, ATLAS, CMS and LHCb experiments will include higher granularity and
radiation hard sensors. The radiation hardness of the new sensors must be
roughly an order of magnitude higher than the one of LHC detectors. To address
this, a massive R&D program is underway within the CERN RD50 collaboration
"Development of Radiation Hard Semiconductor Devices for Very High Luminosity
Colliders" to develop silicon sensors with sufficient radiation tolerance.
Research topics include the improvement of the intrinsic radiation tolerance of
the sensor material and novel detector designs with benefits like reduced
trapping probability (thinned and 3D sensors), maximized sensitive area (active
edge sensors) and enhanced charge carrier generation (sensors with intrinsic
gain). A review of the recent results from both measurements and TCAD
simulations of several detector technologies and silicon materials at radiation
levels expected for HL-LHC will be presented.Comment: 7 pages, 9 figures, 10th International Conference on Radiation
Effects on Semiconductor Materials, Detectors and Devices (RESMDD14), 8-10
October, Firenze, Ital
Characterization of Thin p-on-p Radiation Detectors with Active Edges
Active edge p-on-p silicon pixel detectors with thickness of 100 m were
fabricated on 150 mm Float zone silicon wafers at VTT. By combining measured
results and TCAD simulations, a detailed study of electric field distributions
and charge collection performances as a function of applied voltage in a p-on-p
detector was carried out. A comparison with the results of a more conventional
active edge p-on-n pixel sensor is presented. The results from 3D spatial
mapping show that at pixel-to-edge distances less than 100 m the sensitive
volume is extended to the physical edge of the detector when the applied
voltage is above full depletion. The results from a spectroscopic measurement
demonstrate a good functionality of the edge pixels. The interpixel isolation
above full depletion and the breakdown voltage were found to be equal to the
p-on-n sensor while lower charge collection was observed in the p-on-p pixel
sensor below 80 V. Simulations indicated this to be partly a result of a more
favourable weighting field in the p-on-n sensor and partly of lower hole
lifetimes in the p-bulk.Comment: 23 pages, 16 figures, 1 tabl
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