28 research outputs found
Operational Experience with the CMS Pixel Detector
In the first LHC running period the CMS-pixel detector had to face various
operational challenges and had to adapt to the rapidly changing beam
conditions. In order to maximize the physics potential and the quality of the
data, online and offline calibrations were performed on a regular basis. The
detector performed excellently with an average hit efficiency above 99% for all
layers and disks. In this contribution the operational challenges of the
silicon pixel detector in the first LHC run and the current long shutdown are
summarized and the expectations for 2015 are discussed.Comment: Pixel2014 Conference proceedin
Results on Proton-Irradiated 3D Pixel Sensors Interconnected to RD53A Readout ASIC
Test beam results obtained with 3D pixel sensors bump-bonded to the RD53A
prototype readout ASIC are reported. Sensors from FBK (Italy) and IMB-CNM
(Spain) have been tested before and after proton-irradiation to an equivalent
fluence of about cm (1 MeV
equivalent neutrons). This is the first time that one single collecting
electrode fine pitch 3D sensors are irradiated up to such fluence bump-bonded
to a fine pitch ASIC. The preliminary analysis of the collected data shows no
degradation on the hit detection efficiencies of the tested sensors after high
energy proton irradiation, demonstrating the excellent radiation tolerance of
the 3D pixel sensors. Thus, they will be excellent candidates for the extreme
radiation environment at the innermost layers of the HL-LHC experiments.Comment: Conference Proceedings of VCI2019, 15th Vienna Conference of
Instrumentation, February 18-22, 2019, Vienna, Austria. arXiv admin note:
text overlap with arXiv:1903.0196
A monolithic ASIC demonstrator for the Thin Time-of-Flight PET scanner
Time-of-flight measurement is an important advancement in PET scanners to
improve image reconstruction with a lower delivered radiation dose. This
article describes the monolithic ASIC for the TT-PET project, a novel idea for
a high-precision PET scanner for small animals. The chip uses a SiGe Bi-CMOS
process for timing measurements, integrating a fully-depleted pixel matrix with
a low-power BJT-based front-end per channel, integrated on the same 100 thick die. The target timing resolution is 30 ps RMS for electrons from the
conversion of 511 keV photons. A novel synchronization scheme using a
patent-pending TDC is used to allow the synchronization of 1.6 million channels
across almost 2000 different chips at picosecond-level. A full-featured
demonstrator chip with a 3x10 matrix of 500x500 pixels was
produced to validate each block. Its design and experimental results are
presented here
Design and standalone characterisation of a capacitively coupled HV-CMOS sensor chip for the CLIC vertex detector
The concept of capacitive coupling between sensors and readout chips is under
study for the vertex detector at the proposed high-energy CLIC electron
positron collider. The CLICpix Capacitively Coupled Pixel Detector (C3PD) is an
active High-Voltage CMOS sensor, designed to be capacitively coupled to the
CLICpix2 readout chip. The chip is implemented in a commercial nm HV-CMOS
process and contains a matrix of square pixels with m
pitch. First prototypes have been produced with a standard resistivity of
cm for the substrate and tested in standalone mode. The
results show a rise time of ns, charge gain of mV/ke and
e RMS noise for a power consumption of W/pixel. The
main design aspects, as well as standalone measurement results, are presented.Comment: 13 pages, 13 figures, 2 tables. Work carried out in the framework of
the CLICdp collaboratio
Dedicated multichannel readout ASIC coupled with single crystal diamond for dosimeter application
This paper reports on the tests of a low-noise, multi-channel readout integrated circuit used as a readout electronic front-end for a diamond multi-pixel dosimeter. The system is developed for dose distribution measurement in radiotherapy applications. The first 10-channel prototype chip was designed and fabricated in a 0.18 um CMOS process. Every channel includes a charge integrator with a 10 pF capacitor and a double slope A/D converter. The diamond multi-pixel detector, based on CVD synthetic single crystal diamond Schottky diodes, is made by a 3 × 3 sensor matrix. The overall device has been tested under irradiation with 6 MeV radio therapeutic photon beams at the Policlinico ``Tor Vergata'' (PTV) hospital. Measurements show a 20 fA RMS leakage current from the front-end input stage and a negligible dark current from the diamond detector, a stable temporal response and a good linear behaviour as a function of both dose and dose rate. These characteristics were common to each tested channel
The RD53 Collaboration's SystemVerilog-UVM Simulation Framework and its General Applicability to Design of Advanced Pixel Readout Chips
The foreseen Phase 2 pixel upgrades at the LHC have very challenging
requirements for the design of hybrid pixel readout chips. A versatile pixel
simulation platform is as an essential development tool for the design,
verification and optimization of both the system architecture and the pixel
chip building blocks (Intellectual Properties, IPs). This work is focused on
the implemented simulation and verification environment named VEPIX53, built
using the SystemVerilog language and the Universal Verification Methodology
(UVM) class library in the framework of the RD53 Collaboration. The environment
supports pixel chips at different levels of description: its reusable
components feature the generation of different classes of parameterized input
hits to the pixel matrix, monitoring of pixel chip inputs and outputs,
conformity checks between predicted and actual outputs and collection of
statistics on system performance. The environment has been tested performing a
study of shared architectures of the trigger latency buffering section of pixel
chips. A fully shared architecture and a distributed one have been described at
behavioral level and simulated; the resulting memory occupancy statistics and
hit loss rates have subsequently been compared.Comment: 15 pages, 10 figures (11 figure files), submitted to Journal of
Instrumentatio
PIXIE III: a very large area photon-counting CMOS pixel ASIC for sharp X-ray spectral imaging
PIXIE III is the third generation of very large area (32 x 25 mm(2)) pixel ASICs developed by Pixirad Imaging Counters s. r. l. to be used in combination with suitable X-ray sensor materials (Silicon, CdTe, GaAs) in hybrid assemblies using flip-chip bonding. A Pixirad unit module based on PIXIE III shows several advances compared to what has been available up to now. It has a very broad energy range (from 2 to 100 keV before full pulse saturation), high speed (100 ns peaking time), high frame rate (larger than 500 fps), dead-time-free operation, good energy resolution (around 2 keV at 20 keV), high photo-peak fraction and sharp spectral separation between the color images. In this paper the results obtained with PIXIE III both in a test bench set-up as well in X-ray imaging applications are discussed
Energy characterization of Pixirad-1 photon counting detector system
This work is focused on the characterization of the Pixirad-1 detector system from the spectroscopic point of view. An energy calibration has been carried out using different X-ray sources such as fluorescence lines, synchrotron radiation and radioactive elements. The energy resolution has been measured as function of the energy and the results have been compared with theoretical estimation. Last, the charge sharing fraction has been evaluated by exploiting the monochromatic energy of the Elettra synchrotron beam