The ATLAS experiment at the LHC will replace its current inner tracker system for the HL-LHC era. 3D silicon pixel sensors are being considered as radiation-hard candidates for the innermost layers ...of the new fully silicon-based tracking detector. 3D sensors with a small pixel size of (50x50) μm2 and (25x100) μm2 compatible with the first prototype ASIC for the HL-LHC, the RD53A chip, have been studied in beam tests after uniform irradiation to 5×1015 neq/cm2. An operation voltage of only 50 V is needed to achieve a 97% hit efficiency after this fluence.
INFN-FBK developments of 3D sensors for High-Luminosity LHC Oide, H.; Alimonti, G.; Boscardin, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2019, Letnik:
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3D type of pixel sensors is a promising option for the innermost pixel layer at the High-Luminosity LHC. However, the required very high hit-rate capabilities, finer pixel granularity, extreme ...radiation hardness and reduced material budget call for a downscale of the pixel size as compared to existing 3D sensors, involving smaller pitch (e.g. 50 × 50 or 25×100μm2), shorter inter-electrode spacing (∼30μm), narrower electrodes (∼6μm diameter), and reduced active thickness (∼100–150μm). Within a joint R&D effort with INFN, FBK has produced a new generation of 3D pixel sensors with these challenging features. In this talk preliminary results from the electrical and functional characterisation of the first prototypes are reported, included their behaviour after large radiation fluence, close to the ones expected in the High Luminosity LHC environment. Prospects for the next prototypes are also presented.
Chemical Vapour Deposition (CVD) diamond is being considered as a material for particle detectors in a harsh radiation environment. This article presents beam test results of 3D pixel detectors ...fabricated with poly-crystalline CVD diamonds. The cells of the devices had a size of 50µm×50µm with columns 2.6µm in diameter. The cells were ganged in a 3×2 and 5×1 pattern to match the layouts of the pixel read-out electronics currently used in the CMS and ATLAS experiments at the Large Hadron Collider, respectively. In beam tests, using tracks reconstructed with a high precision tracking telescope, a tracking efficiency of 99.3% was achieved. The efficiency of both devices plateaus at a bias voltage of 30V. Also irradiated poly-crystalline CVD diamond pad detectors were investigated. In high rate beam tests with particle fluxes up to 20MHz/cm2 and irradiations up to 8 ⋅ 1015n/cm2 it was shown that the pulse height of irradiated poly-crystalline CVD diamonds does not depend on flux to the O2%.
The ATLAS experiment at the LHC will replace its current inner tracker system for the HL-LHC era. 3D silicon pixel sensors are being considered as radiation-hard candidates for the innermost layers ...of the new fully silicon-based tracking detector. 3D sensors with a small pixel size of \(\mathrm{50 \times 50~\mu m^{2}}\) and \(\mathrm{25 \times 100~\mu m^{2}}\) compatible with the first prototype ASIC for the HL-LHC, the RD53A chip, have been studied in beam tests after uniform irradiation to \(\mathrm{5 \times 10^{15}~n_{eq}/cm^{2}}\). An operation voltage of only 50 V is needed to achieve a 97% hit efficiency after this fluence.
Small-pitch 3D silicon pixel detectors have been investigated as radiation-hard candidates for the innermost layers of the HL-LHC pixel detector upgrades. Prototype 3D sensors with pixel sizes of ...50×50 and 25×100μm2 connected to the existing ATLAS FE-I4 readout chip have been produced by CNM Barcelona. Irradiations up to particle fluences of 3×1016 neq/cm2, beyond the full expected HL-LHC fluences at the end of lifetime, have been carried out at Karlsruhe and CERN. The performance of the 50×50μm2 devices has been measured in the laboratory and beam tests at CERN SPS. A high charge collected and a high hit efficiency of 98% were found up to the highest fluence. The bias voltage to reach the target efficiency of 97% at perpendicular beam incidence was found to be about 100 V at 1.4×1016 neq/cm2 and 150 V at 2.8×1016 neq/cm2, significantly lower than for the previous IBL 3D generation with larger inter-electrode distance and than for planar sensors. The power dissipation at -25°C and 1.4×1016 neq/cm2 was found to be 13 mW/cm2. Hence, 3D pixel detectors demonstrated superior radiation hardness and were chosen as the baseline for the inner layer of the ATLAS HL-LHC pixel detector upgrade.
A new generation of 3D silicon pixel detectors with a small pixel size of 50\(\times\)50 and 25\(\times\)100 \(\mu\)m\(^{2}\) is being developed for the HL-LHC tracker upgrades. The radiation ...hardness of such detectors was studied in beam tests after irradiation to HL-LHC fluences up to \(1.4\times10^{16}\) n\(_{\mathrm{eq}}\)/cm\(^2\). At this fluence, an operation voltage of only 100 V is needed to achieve 97% hit efficiency, with a power dissipation of 13 mW/cm\(^2\) at -25\(^{\circ}\)C, considerably lower than for previous 3D sensor generations and planar sensors.
3D silicon pixel detectors have been investigated as radiation-hard candidates for the innermost layers of the HL-LHC upgrade of the ATLAS pixel detector. 3D detectors are already in use today in the ...ATLAS IBL and AFP experiments. These are based on 50x250 um2 large pixels connected to the FE-I4 readout chip. Detectors of this generation were irradiated to HL-LHC fluences and demonstrated excellent radiation hardness with operational voltages as low as 180 V and power dissipation of 12--15 mW/cm2 at a fluence of about 1e16 neq/cm2, measured at -25 degree C. Moreover, to cope with the higher occupancies expected at the HL-LHC, a first run of a new generation of 3D detectors designed for the HL-LHC was produced at CNM with small pixel sizes of 50x50 and 25x100 um2, matched to the FE-I4 chip. They demonstrated a good performance in the laboratory and in beam tests with hit efficiencies of about 97% at already 1--2V before irradiation.
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