A DATA ACQUISITION AND CONTROL SYSTEM FOR AN EXPERIMENT OF PP COLLIDING BEAMS AT THE ENERGY OF 14 TEV IN THE CENTER OF MASS: CMS DETECTOR AT THE LHC ACCELERATOR

ΠΑΡΟΥΣΙΑΖΕΤΑΙ Η ΜΕΛΕΤΗ ΤΗΣ ΑΡΧΙΤΕΚΤΟΝΙΚΗΣ ΕΝΟΣ ΣΥΣΤΗΜΑΤΟΣ ΛΗΨΗΣ ΔΕΔΟΜΕΝΩΝ ΚΑΙ ΕΛΕΓΧΟΥ ΓΙΑ ΤΟΝ ΑΝΙΧΝΕΥΤΗ ΠΡΟΕΝΤΟΠΙΣΜΟΥ ΚΑΤΑΙΓΙΣΜΩΝ (PRESHOWER) ΤΟΥ ΗΛΕΚΤΡΟΜΑΓΝΗΤΙΚΟΥ ΚΑΛΟΡΙΜΕΤΡΟΥ ΤΟΥ ΠΕΙΡΑΜΑΤΟΣ CMS (COMPACT MUON SOLENOID) ΣΤΟΝ ΕΠΙΤΑΧΥΤΗ LHC (LARGE HADRON COLLIDER) ΤΟΥ CERN. ΤΟ ΣΥΣΤΗΜΑ ΑΠΟΤΕΛΕΙΤΑΙ ΑΠΟ ΤΑ ΗΛΕΚΤΡΟΝΙΚΑ ΤΟΥ ΑΝΙΧΝΕΥΤΗ (FRONT END ELECTRONICS) ΚΑΘΩΣ ΚΑΙ ΑΠΟ ΤΟ ΣΥΣΤΗΜΑ ΜΕΤΑΔΟΣΗΣ ΔΕΔΟΜΕΝΩΝ ΑΠΟ ΤΑ ΗΛΕΚΤΡΟΝΙΚΑ ΤΟΥ ΑΝΙΧΝΕΥΤΗ ΣΤΟ ΚΕΝΤΡΙΚΟ ΣΥΣΤΗΜΑ ΛΗΨΗΣ ΔΕΔΟΜΕΝΩΝ ΤΟΥ ΠΕΙΡΑΜΑΤΟΣ CMS. ΠΕΡΙΓΡΑΦΕΤΑΙ Η ΛΕΙΤΟΥΡΓΙΑ ΤΗΣ ΕΠΕΞΕΡΓΑΣΙΑΣ ΤΩΝ ΗΛΕΚΤΡΙΚΩΝ ΣΗΜΑΤΩΝ ΑΠΟ ΤΑ ΗΛΕΚΤΡΟΝΙΚΑ ΤΟΥ ΑΝΙΧΝΕΥΤΗ, ΚΑΙ ΥΠΟΛΟΓΙΖΟΝΤΑΙ ΟΙ ΚΑΤΑΣΚΕΥΑΣΤΙΚΕΣ ΠΑΡΑΜΕΤΡΟΙ ΤΟΥ ΣΥΣΤΗΜΑΤΟΣ ΜΕΤΑΔΟΣΗΣ ΔΕΔΟΜΕΝΩΝ ΑΡΧΙΤΕΚΤΟΝΙΚΗΣ ΔΑΚΤΥΛΙΟΥ.Ο ΣΧΕΔΙΑΣΜΟΣ ΤΟΥ ΣΥΣΤΗΜΑΤΟΣ ΕΓΙΝΕ ΜΕ ΓΝΩΜΟΝΑ ΤΗΝ ΑΞΙΟΠΙΣΤΙΑ, ΤΗΝ ΧΡΗΣΗ ΟΠΤΟΗΛΕΚΤΡΟΝΙΚΩΝ ΑΝΘΕΚΤΙΚΩΝ ΣΤΗΝ ΡΑΔΙΕΝΕΡΓΗ ΑΚΤΙΝΟΒΟΛΙΑ, ΤΗΝ ΧΑΜΗΛΗ ΚΑΤΑΝΑΛΩΣΗ ΡΕΥΜΑΤΟΣ, ΚΑΙ ΤΗΝ ΕΛΑΧΙΣΤΟΠΟΙΗΣΗ ΤΟΥ ΑΡΙΘΜΟΥ ΤΩΝ ΜΙΚΡΟΗΛΕΚΤΡΟΝΙΚΩΝ ΚΥΚΛΩΜΑΤΩΝ ΕΙΔΙΚΩΝ ΣΧΕΔΙΑΣΜΟΥ (APPLICATION SPECIFIC INTEGRATED CIRCUITS, ASICS) ΠΟΥ ΑΠΑΙΤΟΥΝΤΑΙ ΓΙΑ ΤΗΝ ΥΛΟΠΟΙΗΣΗ ΤΟΥ ΣΥΣΤΗΜΑΤΟΣ. ΔΙΕΡΕΥΝΑΤΑΙ Η ΧΡΗΣΗ ΕΜΠΟΡΙΚΑ ΔΙΑΘΕΣΙΜΩΝ ΤΕΧΝΟΛΟΓΙΩΝ ΓΙΑ ΤΗΝ ΚΑΤΑΣΚΕΥΗ ΤΩΝ ΜΙΚΡΟΚΥΚΛΩΜΑΤΩΝ ΕΙΔΙΚΟΥ ΣΧΕΔΙΑΣΜΟΥ, ΑΝΘΕΚΤΙΚΩΝ ΣΤΗΝ ΡΑΔΙΕΝΕΡΓΕΙΑ, ΠΟΥ ΑΠΑΙΤΟΥΝΤΑΙ ΓΙΑ ΤΗΝ ΥΛΟΠΟΙΗΣΗ ΤΩΝ ΗΛΕΚΤΡΟΝΙΚΩΝ ΤΟΥ ΑΝΙΧΝΕΥΤΗ PRESHOWER. ΜΕΛΕΤΑΤΑΙ Η ΑΝΤΟΧΗ ΣΤΗΝ ΙΟΝΙΖΟΥΣΑ ΑΚΤΙΝΟΒΟΛΙΑ ΜΙΑΣ ΕΜΠΟΡΙΚΑ ΔΙΑΘΕΣΙΜΗΣ ΤΕΧΝΟΛΟΓΙΑΣ ΚΑΤΑΣΚΕΥΗΣ ΜΙΚΡΟΚΥΚΛΩΜΑΤΩΝ ΤΥΠΟΥ BICMOS 0.8Μ. ΜΕΤΑ ΑΠΟ ΟΛΙΚΗ ΔΟΣΗ ΑΚΤΙΝΟΒΟΛΙΑΣ 1.3M RAD, Η ΜΕΤΑΤΟΠΙΣΗ ΤΗΣ ΤΑΣΗΣ ΚΑΤΩΦΛΙΟΥ ΒΡΕΘΗΚΕ ΙΣΗ ΜΕ -130MV ΓΙΑ ΤΑ NMOS ΚΑΙ ΜΕ -190MV ΓΙΑ ΤΑ PMOS (ΠΕΡΙΚΟΠΗ ΠΕΡΙΛΗΨΗΣ)THE ARCHITECTURE OF A DATA ACQUISITION (DAQ) AND SLOW CONTROL SYSTEM FOR THE ELECTROMAGNETIC CALORIMETER PRESHOWER DETECTOR OF THE CMS (COMPACT MUON SOLENOID) EXPERIMENT - ONE OF THE LHC (LARGE HADRON COLLIDER) EXPERIMENTS OF CERN - HAS BEEN STUDIED. THE SYSTEM CONCISTS OF THE DETECTOR FRONT END ELECTRONICS ANDOF A DATA TRANSMISSION SYSTEM DELIVERING THE PRESHOWER INFORMATION TO THE CENTRAL DAQ SYSTEM OF THE CMS EXPERIMENT. THE FUNCTIONALITY OF THE FRONT END ELECTRONICS IS PRESENTED. THE OPERATION OF THE DATA TRANSMISSION SYSTEM, BASED ON A RING TOPOLOGY, IS DESCRIBED AND THE SYSTEM DESIGN PARAMETERS ARE ESTIMATED. THE SYSTEM DESIGN CRITERIA ARE THE INCREASED RELIABILITY, THE USE OF RADIATION HARD OPTOELECTRONIC COMPONENTS, THE LOW POWER CONSUMPTION AND THE MINIMIZATION OF THE NUMBER OF APPLICATION SPECIFIC INTEGRATED CIRCUITS (ASICS) NEEDED FOR BULDING THE SYSTEM. THE USE OF COMMERCIALLY AVAILABLE VLSI TECHNOLOGIES FOR FABRICATING THE ASICS OF THE PROPOSED SYSTEM CAPABLE TO WITHSTAND THE RADIATION LEVELS IN THE PRESHOWER REGION HAS BEEN INVESTIGATED. THE RADIATION HARDNESS OF A COMMERCIALLY AVAILABLE BICMOS 0.8Μ VLSI TECHNOLOGY HAS BEEN STUDIED. THE RESULTS SHOW A THRESHOLD VOLTAGE SHIFT OF -130MV FOR THE NMOS TRANSISTORS AND -190MV FOR THE PMOS TRANSISTORS, AFTER AN IRRADIATION DOSE OF 1.3MRAD. THE TRANSCONDUCTANCE DROPS ABOUT 8% FOR THE NMOS AND 7% FOR THE PMOS ATTHE SAME IRRADIATION LEVEL. A SUDDEN INCREASE OF LEAKAGE CURRENT WAS OBSERVED AFTER AN IRRADIATION DOSE OF 14K RAD. THE STUDY LOCATED THE LEAKAGE CURRENTS ORIGINATING FROM THE TURN (ABSTRACT TRUNCATED

Readout architecture for the Pixel-Strip module of the CMS Outer Tracker Phase-2 upgrade

The Outer Tracker upgrade of the Compact Muon Solenoid (CMS) experiment at CERN introduces new challenges for the front-end readout electronics. In particular, the capability of identifying particles with high transverse momentum using modules with double sensor layers requires high speed real time interconnects between readout ASICs. The Pixel-Strip module combines a pixelated silicon layer with a silicon-strip layer. Consequently, it needs two different readout ASICs, namely the Short Strip ASIC (SSA) for the strip sensor and the Macro Pixel ASIC (MPA) for the pixelated sensor. The architecture proposed in this paper allows for a total data flow between readout ASICs of $\sim$100\,Gbps and reduces the output data flow from 1.3\,Tbps to 30\,Gbps per module while limiting the total power density to below 100\,mW/cm$^2$. In addition a system-level simulation framework of all the front-end readout ASICs is developed in order to verify the data processing algorithm and the hardware implementation allowing multichip verification with performance evaluation. Finally, power consumption and efficiency performance are estimated and reported for the described readout architecture

A 65 nm pixel readout ASIC with quick transverse momentum discrimination capabilities for the CMS Tracker at HL-LHC

A readout ASIC for the hybrid pixel detector with the capability of performing quick recognition of particles with high transverse momentum has been designed for the requirements of the CMS Outer Tracker at the High Luminosity LHC. The particle momentum dicrimination capability represents the main challenge for this design together with the low power requirement: the constraint of low mass for the new tracker dictates a total power budget of less than 100\,mW/cm$^2$. The choice of a 65\,nm CMOS technology has made it possible to satisfy this power requirement despite the fairly large amount of logic necessary to perform the momentum discrimination and the continuous operation at 40\,MHz. Several techniques for low power have been used to implement this logic that performs cluster reduction, position offset correction and coordinate encoding. A prototype chip including a large part of the final functionality and the full front-end has been realized and comprises a matrix of 16 by 3 rectangular pixels of 100\,$\mu$m\,x\,1446\,$\mu$m, providing 7.65\,mm$^2$ of segmented active area. Measurements of the analog front-end characteristics closely match the simulations and confirm the consumption of $<$\,30\,$\mu$A per pixel. Front-end characterization and irradiation results up to 150\,MRad are also reported

MPA-SSA, design and test of a 65 nm ASIC-based system for particle tracking at HL-LHC featuring on-chip particle discrimination

Particle tracking detectors for High Energy Physics need a new readout technique to cope with the increase of the collision rate foreseen for the High Luminosity LHC upgrade. In particular, the selection of interesting physics events at the first trigger stage becomes extremely challenging at high luminosity, not only because of the rate increase, but also because the selection algorithms become inefficient in high pileup conditions. A substantial increase of latency and trigger rate provides an improvement that is not sufficient to preserve the tracking performance of the current system. A possible solution consists of using tracking information for the event selection. Given a limited bandwidth, the use of tracking information for the event selection implies that the tracker has to send out self-selected information for every event. This is the reason why front-end electronics need to perform a local data reduction. This functionality relies on the capability of continuous particle discrimination on-chip based on the transverse momentum. The high complexity of the digital logic for particle selection and the very low power requirement of $$\,95\,\% in particle selection and a data reduction from $\sim$\,30\,Gbps\,/\,$\text{cm}^2$ to $\sim$\,0.7\,Gbps\,/\,$\text{cm}^2$ Two full-size and full-functionality prototypes, called MPA and SSA, have been designed, produced and tested. These two readout front-end ASICs perform binary readout of silicon modules which combine pixel and strip sensors, full-event storage with triggered readout, and continuous data selection with trigger-less readout

Characterization of the first prototype of the Silicon-Strip readout ASIC (SSA) for the CMS Outer-Tracker phase-2 upgrade

The silicon strip readout ASIC (SSA) for the CMS Outer Tracker PS module was prototyped in a $65\,nm$ CMOS technology and characterized utilizing a custom made test bench based on the FC7 $\mu$TCA FPGA card. The ASIC has been evaluated and characterised under different working temperatures and radiation levels up to $200\,Mrad$. Measurements show a front-end gain between $35$ and $54\,mV/fC$ and an average noise of $<330\,e^-$, meeting the specification of noise performance. The measured peaking time for an injected charge between $0.5\,fC$ and $8\,fC$ is $\approx19\,ns$ allowing to detect consecutive particle events in combination with the zero dead-cycle binary readout. The embedded trimming circuit allows to obtain a measured threshold spread smaller than $55\,e^-$ between channels. The measured power consumption is $\approx60\,mW$ and thus within the strict power budget of the PS modules. The performance characterization results and radiation tolerance test results of the first SSA silicon prototype are presented

Characterization of the MPA prototype, a 65 nm pixel readout ASIC with on-chip quick transverse momentum discrimination capabilities

The first prototype of the full-size, full-functionality Macro Pixel ASIC has been produced in a 65~nm technology employing radiation tolerant techniques. It is a pixel readout ASIC designed for the Phase-2 upgrade of the CMS Outer Tracker detector. It features novel on-chip particle discrimination capabilities allowing for real-time event-driven readout of high transverse momentum particles at a 40~MHz rate. This data flow is complemented with a zero suppressed triggered readout data path for the readout of full events at a maximum rate of 1~MHz. This contribution presents the functional and performance evaluation results obtained from silicon prototypes

The CMS Barrel Calorimeter Response to Particle Beams from 2 to 350 GeV/c

The response of the CMS barrel calorimeter (electromagnetic plus hadronic) to hadrons, electrons and muons over a wide momentum range from 2 to 350 GeV/c has been measured. To our knowledge, this is the widest range of momenta in which any calorimeter system has been studied. These tests, carried out at the H2 beam-line at CERN, provide a wealth of information, especially at low energies. The analysis of the differences in calorimeter response to charged pions, kaons, protons and antiprotons and a detailed discussion of the underlying phenomena are presented. We also show techniques that apply corrections to the signals from the considerably different electromagnetic (EB) and hadronic (HB) barrel calorimeters in reconstructing the energies of hadrons. Above 5 GeV/c, these corrections improve the energy resolution of the combined system where the stochastic term equals 84.7$\pm$1.6$\%$ and the constant term is 7.4$\pm$0.8$\%$. The corrected mean response remains constant within 1.3$\%$ rms

Strategies and performance of the CMS silicon tracker alignment during LHC Run 2

The strategies for and the performance of the CMS silicon tracking system alignment during the 2015–2018 data-taking period of the LHC are described. The alignment procedures during and after data taking are explained. Alignment scenarios are also derived for use in the simulation of the detector response. Systematic effects, related to intrinsic symmetries of the alignment task or to external constraints, are discussed and illustrated for different scenarios

Precision measurement of the structure of the CMS inner tracking system using nuclear interactions

The structure of the CMS inner tracking system has been studied using nuclear interactions of hadrons striking its material. Data from proton-proton collisions at a center-of-mass energy of 13 TeV recorded in 2015 at the LHC are used to reconstruct millions of secondary vertices from these nuclear interactions. Precise positions of the beam pipe and the inner tracking system elements, such as the pixel detector support tube, and barrel pixel detector inner shield and support rails, are determined using these vertices. These measurements are important for detector simulations, detector upgrades, and to identify any changes in the positions of inactive elements