Design and performance of the CMS pixel detector readout chip Kästli, H.Chr; Barbero, M.; Erdmann, W. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2006, Letnik:
565, Številka:
1
Journal Article
Recenzirano
The readout chip for the CMS pixel detector has to deal with an enormous data rate. On-chip zero suppression is inevitable and hit data must be buffered locally during the latency of the first level ...trigger. Dead-time must be kept at a minimum. It is dominated by contributions coming from the readout. To keep it low an analog readout scheme has been adopted where pixel addresses are analog coded.
We present the architecture of the final CMS pixel detector readout chip with special emphasis on the analog readout chain. Measurements of its performance are discussed.
The CMS experiment at the (LHC) includes a hybrid silicon pixel detector for the reconstruction of charged tracks and of the interaction vertices. The barrel region consists of n-in-n sensors with
...100
×
150
μ
m
2
cell size processed on diffusion oxygenated float zone silicon. A biasing grid is implemented and pixel isolation is achieved with the moderated p-spray technique. An extensive test program was carried out on the H
2 beam line of the CERN-SPS. In this paper we describe the sensor layout, the beam test setup and the results obtained with both irradiated and non-irradiated prototype devices. Measurements of charge collection, hit detection efficiency, Lorentz angle and spatial resolution are presented.
Performance of the CMS pixel detector at an upgraded LHC Horisberger, R.; Kotliński, D.; Rohe, T.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2006, Letnik:
568, Številka:
1
Journal Article
Recenzirano
The CMS experiment will include a pixel detector for pattern recognition and vertexing. It will consist of three barrel layers and two endcaps on each side, providing three space-points up to a ...pseudorapidity of 2.1. Taking into account the expected limitations of its performance in the LHC environment an 8–9 layers pixel detector for an upgraded LHC is discussed.
CMS barrel pixel detector overview Kästli, H.Chr; Bertl, W.; Erdmann, W. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2007, Letnik:
582, Številka:
3
Journal Article
Recenzirano
The pixel detector is the innermost tracking device of the CMS experiment at the LHC. It is built from two independent subdevices, the pixel barrel and the end disks. The barrel consists of three ...concentric layers around the beam pipe with mean radii of 4.4, 7.3 and 10.2
cm. There are two end disks on each side of the interaction point at
±
34.5
and
±
46.5
cm
.
This article gives an overview of the pixel barrel detector, its mechanical support structure, electronics components, services and its expected performance.
Upgrade plans for the CMS pixel barrel detector Erdmann, W.; Bertl, W.; Horisberger, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2010, Letnik:
617, Številka:
1
Journal Article
Recenzirano
The pixel detector of the CMS experiment will need to be replaced after a couple of years of LHC running because of radiation damage. On the other hand, plans for a step wise luminosity upgrade of ...the accelerator beyond the present design value around 2014 are being prepared. While the replacement pixel detector must be designed to handle increased particle rates, it should maintain or improve the tracking performance of the present system and must be compatible with existing services.
Charge collection measurements performed on heavily irradiated p-spray DOFZ pixel sensors with a grazing angle hadron beam provide a sensitive determination of the electric field within the ...detectors. The data are compared with a complete charge transport simulation of the sensor which includes free carrier trapping and charge induction effects. A linearly varying electric field based upon the standard picture of a constant type-inverted effective doping density is inconsistent with the data. A two-trap double junction model implemented in the ISE TCAD software can be tuned to produce a double peak electric field which describes the data reasonably well. The modeled field differs somewhat from previous determinations based upon the transient current technique. The model can also account for the level of charge trapping observed in the data.
We show that doubly peaked electric fields are necessary to describe grazing-angle charge collection measurements of irradiated silicon pixel sensors. A model of irradiated silicon based upon two ...defect levels with opposite charge states and the trapping of charge carriers can be tuned to produce a good description of the measured charge collection profiles in the fluence range from
0.5
×
10
14
to
5.9
×
10
14
n
eq
/
cm
2
. The model correctly predicts the variation in the profiles as the temperature is changed from
-
10
to
-
25
∘
C
. The measured charge collection profiles are inconsistent with the linearly varying electric fields predicted by the usual description based upon a uniform effective doping density. This observation calls into question the practice of using effective doping densities to characterize irradiated silicon.
A double junction model of irradiated silicon pixel sensors for LHC Chiochia, V.; Swartz, M.; Allkofer, Y. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2006, Letnik:
568, Številka:
1
Journal Article
Recenzirano
Odprti dostop
In this paper, we discuss the measurement of charge collection in irradiated silicon pixel sensors and the comparison with a detailed simulation. The simulation implements a model of radiation damage ...by including two defect levels with opposite charge states and trapping of charge carriers. The modeling proves that a doubly peaked electric field generated by the two defect levels is necessary to describe the data and excludes a description based on acceptor defects uniformly distributed across the sensor bulk. In addition, the dependence of trap concentrations upon fluence is established by comparing the measured and simulated profiles at several fluences and bias voltages.
Design and test of the CMS pixel readout chip Barbero, M.; Bertl, W.; Dietrich, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2004, Letnik:
517, Številka:
1
Journal Article
Recenzirano
The readout chip for the CMS pixel detector must handle an enormous flux of data, while keeping the data loss at a minimum. Full size prototype readout chips bump-bonded to sensors have been tested ...in a pion beam simulating an LHC-like environment, and the data loss as a function of particle fluence has been measured.
PDF
