The upgrade of the LHC to the High-Luminosity LHC (HL-LHC) is expected to increase the LHC design luminosity by an order of magnitude. This will require silicon tracking detectors with a ...significantly higher radiation hardness. The CMS Tracker Collaboration has conducted an irradiation and measurement campaign to identify suitable silicon sensor materials and strip designs for the future outer tracker at the CMS experiment. Based on these results, the collaboration has chosen to use n-in-p type silicon sensors and focus further investigations on the optimization of that sensor type. This paper describes the main measurement results and conclusions that motivated this decision.
The high luminosity upgrade of the Large Hadron Collider, foreseen for 2026, necessitates the replacement of the CMS experiment’s silicon tracker. The innermost layer of the new pixel detector will ...be exposed to severe radiation, corresponding to a 1 MeV neutron equivalent fluence of up to
Φ
e
q
=
2
×
10
16
cm
-
2
, and an ionising dose of
≈
5
MGy after an integrated luminosity of 3000 fb
-
1
. Thin, planar silicon sensors are good candidates for this application, since the degradation of the signal produced by traversing particles is less severe than for thicker devices. In this paper, the results obtained from the characterisation of 100 and 200
μ
m thick p-bulk pad diodes and strip sensors irradiated up to fluences of
Φ
e
q
=
1.3
×
10
16
cm
-
2
are shown.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Optimization of the silicon sensors for the CMS tracker Albergo, S.; Angarano, M.; Azzi, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2001, Letnik:
466, Številka:
2
Journal Article
Recenzirano
The CMS experiment at the LHC will comprise a large silicon strip tracker. This article highlights some of the results obtained in the R&D studies for the optimization of its silicon sensors. ...Measurements of the capacitances and of the high voltage stability of the devices are presented before and after irradiation to the dose expected after the full lifetime of the tracker.
CMS silicon tracker developments Civinini, C; Albergo, S; Angarano, M ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2002, Letnik:
477, Številka:
1
Journal Article
Recenzirano
The CMS Silicon tracker consists of
70
m
2
of microstrip sensors which design will be finalized at the end of 1999 on the basis of systematic studies of device characteristics as function of the most ...important parameters. A fundamental constraint comes from the fact that the detector has to be operated in a very hostile radiation environment with full efficiency. We present an overview of the current results and prospects for converging on a final set of parameters for the silicon tracker sensors.
We present beam test results on AC-coupled, single-sided, n
+-on-n type silicon microstrip detectors. We have tested the detectors before and after irradiation at a fluence of 8.3×10
13
n/cm
2, at ...different temperatures and bias voltages. Signal-to-noise ratio, spatial resolution, charge collection and overall efficiency have been measured.
Capacitance, resistance and current measurements were carried out on single-sided, n
+ on n silicon strip detectors. We studied the type inversion after irradiating the detectors with neutron ...fluences up to
8.3×10
13
neutron/
cm
2
. To understand the macroscopic irradiation effects, a SPICE model of the detector was developed. Simulating the capacitance measurements, we were able to reproduce the measured frequency dependence of the relevant capacitances, both for non-irradiated and for irradiated detectors.
Impact of low-dose electron irradiation on n+p silicon strip sensors Adam, W.; Baulieu, G.; Boudoul, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2015, Letnik:
803, Številka:
C
Journal Article
Recenzirano
Odprti dostop
The response of n+p silicon strip sensors to electrons from a 90Sr source was measured using a multi-channel read-out system with 25ns sampling time. The measurements were performed over a period of ...several weeks, during which the operating conditions were varied. The sensors were fabricated by Hamamatsu Photonics on 200μm thick float-zone and magnetic-Czochralski silicon. Their pitch was 80μm, and both p-stop and p-spray isolation of the n+ strips were studied. The electrons from the 90Sr source were collimated to a spot with a full-width-at-half-maximum of 2mm at the sensor surface, and the dose rate in the SiO2 at the maximum was about 50Gy(SiO2)/d. After only a few hours of making measurements, significant changes in charge collection and charge sharing were observed. Annealing studies, with temperatures up to 80°C and annealing times of 18h showed that the changes can only be partially annealed. The observations can be qualitatively explained by the increase of the positive oxide-charge density due to the ionization of the SiO2 by the radiation from the β source. TCAD simulations of the electric field in the sensor for different oxide-charge densities and different boundary conditions at the sensor surface support this explanation. The relevance of the measurements for the design of n+p strip sensors is discussed.
A new pixel detector for the CMS experiment was built in order to cope with the instantaneous luminosities anticipated for the Phase~I Upgrade of the LHC. The new CMS pixel detector provides four-hit ...tracking with a reduced material budget as well as new cooling and powering schemes. A new front-end readout chip mitigates buffering and bandwidth limitations, and allows operation at low comparator thresholds. In this paper, comprehensive test beam studies are presented, which have been conducted to verify the design and to quantify the performance of the new detector assemblies in terms of tracking efficiency and spatial resolution. Under optimal conditions, the tracking efficiency is \(99.95\pm0.05\,\%\), while the intrinsic spatial resolutions are \(4.80\pm0.25\,\mu \mathrm{m}\) and \(7.99\pm0.21\,\mu \mathrm{m}\) along the \(100\,\mu \mathrm{m}\) and \(150\,\mu \mathrm{m}\) pixel pitch, respectively. The findings are compared to a detailed Monte Carlo simulation of the pixel detector and good agreement is found.
We present results obtained with full-size wedge silicon microstrip detectors bonded to APV6 (Raymond et al., Proceedings of the 3rd Workshop on Electronics for LHC Experiments, CERN/LHCC/97-60) ...readout chips. We used two identical modules, each consisting of two crystals bonded together. One module was irradiated with
1.7×10
14
neutrons/cm
2
. The detectors have been characterized both in the laboratory and by exposing them to a beam of minimum ionizing particles. The results obtained are a good starting point for the evaluation of the performance of the “ensemble” detector plus readout chip in a version very similar to the final production one. We detected the signal from minimum ionizing particles with a signal-to-noise ratio ranging from 9.3 for the irradiated detector up to 20.5 for the non-irradiated detector, provided the parameters of the readout chips are carefully tuned.
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