Projects / Programmes
Depleted CMOS Sensors for the ATLAS Tracker Upgrade and Future Collider Experiments
| Code |
Science |
Field |
Subfield |
| 1.02.00 |
Natural sciences and mathematics |
Physics |
|
| Code |
Science |
Field |
| P210 |
Natural sciences and mathematics |
Elementary particle physics, quantum field theory |
| Code |
Science |
Field |
| 1.03 |
Natural Sciences |
Physical sciences |
CERN, Large Hadron Collider, ATLAS detector, upgrade, solid state detectors, tehnologija HV-CMOS, HR-CMOS, charge collection, radiation damage
Researchers (10)
Organisations (2)
Abstract
In this research project we propose studies of charge collection properties and radiation hardness of detectors fabricated in CMOS technology. The detectors are being developed for charged particle tracking in the very harsh radiation environment in experiments at the upgraded high luminosity hadron collider HL-LHC. This technology opens the possibility to produce particle detectors with superb spatial resolution in a standard processes in foundries producing commercial electronic chips. The technology offers the potential to produce monolithic detectors with sensor and readout electronics integrated onto the same chip with sufficient speed and radiation hardness for the HL-LHC environment. Successful development of monolithic detectors in CMOS technology would bring detectors with excellent tracking performance, lower mass, large savings in cost and much faster detector production. CMOS detector technology is also a viable candidate for application in future particle physics facilities like CLIC and FCC planned beyond the HL-LHC.
CMOS detectors have already been successfully used for charge particle tracking but they were not suitable for the HL-LHC environment due to their low speed and poor radiation hardness. The reason was that diffusion was the main charge collection mechanism in these detectors. Designs of CMOS detectors for HL-LHC allow for usage of higher bias voltages. Therefore significant depletion depths can be achieved and charge collected by drift to assure sufficient speed and radiation hardness. Another possibility for HL-LHC is CMOS on a thin layer of high resistivity epitaxial material that gets depleted at relatively low bias voltages. This design employs a charge-collecting electrode of a small area to reduce capacitance, and thus minimize noise and power. One of the main open questions in CMOS detector development is the efficiency of charge collection after irradiation to high hadron fluences. A parameter closely related to this issue is the initial resistivity of detector material. This can span across a wide range in CMOS detectors so radiation induced initial acceptor removal plays an important role and will be studied within this project.
Charge collection and its dependence on irradiation fluence will be studied with Edge-TCT, with measurements of signals from 90Sr source and in test beam experiments. Measurements will be done with passive test structures and with segmented active pixel arrays. The test structures will be designed by partner groups participating in collaborations formed at CERN to study this detector technology and the samples shall be acquired through these collaborations. Samples will be irradiated with neutrons in the reactor in Ljubljana and with charged hadrons at other irradiation facilities for example at the CERN PS.
The outcome of this project will significantly contribute to knowledge of CMOS detector technology for particle trackers and will have a decisive impact on the technology choice for the pixel detector in the upgraded ATLAS experiment. It shall also provide guidelines for further research oriented towards tracking detectors for experiments at future colliders.
Significance for science
Research by the ATLAS experiment, supported in its upgrade plans by the proposed project, represents a challenging task at the very frontier of contemporary scientific endeavour, utilizing vast human and financial resources and stretching or even extending existing technologies to render the experiments possible. The experiment has been heavily scrutinized and finally approved by research committees, composed of leading experts from the field and beyond. They represent a joint effort of the global scientific community, and are constantly monitored by scientists as well as by the authorities that are funding them. Their task is to deepen our insight into constituents of matter and the forces acting between them. In this quest accelerators of highest energies and luminosities are used, to probe high energy densities, as they existed a glimpse after the Big Bang that created the Universe. These upgraded experiments will have a good chance of finding signatures and exploring physics beyond the Standard model, be it the predicted and long awaited supersymmety or some more exotic realization of physics at a larger energy scale.
The detector project is heavily interlinked with the ATLAS and CERN RD-50 collaborations, where progress and achievements are periodically controlled by the LHCC committee. Upgrade projects of the experiments are subject to both internal scrutiny as well as control of the respective funding agencies.
The results of the proposed project will bring new knowledge to detector physics and novel methods of particle detection. But most importantly, this progress in detectors will enable the targeted experiment to function properly at the upgraded collider, discover signatures of New Physics and evaluate its properties. They also pave the way for CMOS detectors application in particle trackers at future colliders (CLIC, FCC) in the decades to come.
The CMOS detectors, developed in this project, can be applied to several fields outside their original scope. Their application in the upgraded ATLAS tracker could lead to significant financial and logistic benefits. It would free us from the current high resistivity float zone sensors, where manufacturing is limited to a few small-scale producers, resulting in long lead times and high cost. Any sizable CMOS foundry could produce the complete set of tracker sensors on a time-scale of one month, and the price reduction is expected to be significant.
Significance for the country
Research by the ATLAS experiment, supported in its upgrade plans by the proposed project, represents a challenging task at the very frontier of contemporary scientific endeavour, utilizing vast human and financial resources and stretching or even extending existing technologies to render the experiments possible. The experiment has been heavily scrutinized and finally approved by research committees, composed of leading experts from the field and beyond. They represent a joint effort of the global scientific community, and are constantly monitored by scientists as well as by the authorities that are funding them. Their task is to deepen our insight into constituents of matter and the forces acting between them. In this quest accelerators of highest energies and luminosities are used, to probe high energy densities, as they existed a glimpse after the Big Bang that created the Universe. These upgraded experiments will have a good chance of finding signatures and exploring physics beyond the Standard model, be it the predicted and long awaited supersymmety or some more exotic realization of physics at a larger energy scale.
The detector project is heavily interlinked with the ATLAS and CERN RD-50 collaborations, where progress and achievements are periodically controlled by the LHCC committee. Upgrade projects of the experiments are subject to both internal scrutiny as well as control of the respective funding agencies.
The results of the proposed project will bring new knowledge to detector physics and novel methods of particle detection. But most importantly, this progress in detectors will enable the targeted experiment to function properly at the upgraded collider, discover signatures of New Physics and evaluate its properties. They also pave the way for CMOS detectors application in particle trackers at future colliders (CLIC, FCC) in the decades to come.
The CMOS detectors, developed in this project, can be applied to several fields outside their original scope. Their application in the upgraded ATLAS tracker could lead to significant financial and logistic benefits. It would free us from the current high resistivity float zone sensors, where manufacturing is limited to a few small-scale producers, resulting in long lead times and high cost. Any sizable CMOS foundry could produce the complete set of tracker sensors on a time-scale of one month, and the price reduction is expected to be significant.
Most important scientific results
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Most important socioeconomically and culturally relevant results
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