A vertex detector for the International Linear Collider based on CMOS sensors

Abstract

The physics programme at the International Linear Collider (ILC) calls for a vertex detector (VD) providing unprecedented flavour tagging performances, especially for c-quarks and τ leptons. This requirement makes a very granular, thin and multi-layer VD installed very close to the interaction region mandatory. Additional constraints, mainly on read-out speed and radiation tolerance, originate from the beam background, which governs the occupancy and the radiation level the detector should be able to cope with. CMOS sensors are being developed to fulfil these requirements. This report addresses the ILC requirements (highly related to beamstrahlung), the main advantages and features of CMOS sensors, the demonstrated performances and the specific aspects of a VD based on this technology. The status of the main R&D directions (radiation tolerance, thinning procedure and read-out speed) are also presented

TID Effects in Deep N-Well CMOS Monolithic Active Pixel Sensors

“…Actually, based on the proposed device, the first ever MAPS detectors with pixel-level data sparsification have been designed and produced [5], [6]. Depending on the experiment characteristics and on the position inside the detector, MAPS sensors may be required to withstand a total ionizing dose (TID) which can range from a few hundreds of to a few tens of [7], [8]. This work is concerned with the analysis of ionizing radiation effects on DNW-MAPS fabricated in a 130 nm CMOS technology with triple well feature.…”

Progress on the radiation tolerance of CMOS Monolithic Active Pixel Sensors

“…can be thinned to 50 µm without loss of performance. The charge sharing of the pixels allowed to apply centre-of-charge methods, which improved the spatial resolution to ∼ p/10, where p is the pixel pitch [43]. This has to be compared with a value of p/ √ 12, which holds for pixels showing no charge sharing.…”

Vertex tracking at a future linear collider

“…The factor two increase in the radius of the vertex tracker innermost layer at CLIC compared to the ILC results in a change of the multiple scattering term from 10 µm GeV −1 to 21 µm GeV −1 . Pairs are also responsible for an ionising dose of ∼100 krad/year to be added to a non-ionising dose corresponding to ≃ 7×10 10 n eq cm −2 year −1 from pairs, which is larger than that due to neutrons, estimated to ≃ 10 10 neutrons cm −2 year −1 at 0.5 TeV [17]. These figures are expected to be comparable, ∼100 krad/year and 5×10 10 n cm −2 year −1 , for CLIC at 3 TeV [18].…”