scholarly journals SWATCH: Common software for controlling and monitoring the upgraded level-1 trigger of the CMS experiment

2016 ◽  
Author(s):  
S. Bologna ◽  
G. Codispoti ◽  
G. Dirkx ◽  
L. Kreczko ◽  
C. Lazaridis ◽  
...  
Keyword(s):  
Cms Experiment ◽  
Level 1

scholarly journals The CMS Trigger Upgrade for the HL-LHC

2020 ◽  
Vol 245 ◽  
pp. 01031
Author(s):  
Thiago Rafael Fernandez Perez Tomei
Keyword(s):  
High Performance ◽  
Second Phase ◽  
Level Trigger ◽  
Cms Experiment ◽  
Rejection Factor ◽  
Reconstruction Software ◽  
Efficient Data ◽  
Level 1 ◽  
High Level ◽  
Selection Algorithms

The CMS experiment has been designed with a two-level trigger system: the Level-1 Trigger, implemented on custom-designed electronics, and the High Level Trigger, a streamlined version of the CMS offline reconstruction software running on a computer farm. During its second phase the LHC will reach a luminosity of 7.5 1034 cm−2 s−1 with a pileup of 200 collisions, producing integrated luminosity greater than 3000 fb−1 over the full experimental run. To fully exploit the higher luminosity, the CMS experiment will introduce a more advanced Level-1 Trigger and increase the full readout rate from 100 kHz to 750 kHz. CMS is designing an efficient data-processing hardware trigger that will include tracking information and high-granularity calorimeter information. The current Level-1 conceptual design is expected to take full advantage of advances in FPGA and link technologies over the coming years, providing a high-performance, low-latency system for large throughput and sophisticated data correlation across diverse sources. The higher luminosity, event complexity and input rate present an unprecedented challenge to the High Level Trigger that aims to achieve a similar efficiency and rejection factor as today despite the higher pileup and more pure preselection. In this presentation we will discuss the ongoing studies and prospects for the online reconstruction and selection algorithms for the high-luminosity era.

scholarly journals Level-1 RPC trigger in the CMS experiment—software for emulation and commissioning

2008 ◽  
Vol 119 (3) ◽  
pp. 032012 ◽  
Author(s):  
M Bluj ◽  
K Bunkowski ◽  
T Früboes ◽  
A Kalinowski ◽  
M Konecki ◽  
...  
Keyword(s):  
Cms Experiment ◽  
Level 1

scholarly journals A novel FPGA-based track reconstruction approach for the level-1 trigger of the CMS experiment at CERN

2017 ◽  
Author(s):  
R. Aggleton ◽  
L. Ardila-Perez ◽  
F. A. Ball ◽  
M. N. Balzer ◽  
J. Brooke ◽  
...  
Keyword(s):  
Track Reconstruction ◽  
Cms Experiment ◽  
Level 1

scholarly journals Architecture of a level 1 track trigger for the CMS experiment

2010 ◽  
Vol 5 (08) ◽  
pp. C08004-C08004 ◽  
Author(s):  
E Hazen ◽  
U Heintz ◽  
M Johnson ◽  
R Lipton ◽  
M Narain ◽  
...  
Keyword(s):  
Cms Experiment ◽  
Level 1

scholarly journals The CMS high level trigger

2014 ◽  
Vol 31 ◽  
pp. 1460297 ◽  
Author(s):  
Valentina Gori
Keyword(s):  
Trigger System ◽  
Output Rate ◽  
Computing Power ◽  
Level Trigger ◽  
Cms Experiment ◽  
Pile Up ◽  
Reconstruction Software ◽  
Physics Performance ◽  
Level 1 ◽  
High Level

The CMS experiment has been designed with a 2-level trigger system: the Level 1 Trigger, implemented on custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. A software trigger system requires a tradeoff between the complexity of the algorithms running on the available computing power, the sustainable output rate, and the selection efficiency. Here we will present the performance of the main triggers used during the 2012 data taking, ranging from simpler single-object selections to more complex algorithms combining different objects, and applying analysis-level reconstruction and selection. We will discuss the optimisation of the triggers and the specific techniques to cope with the increasing LHC pile-up, reducing its impact on the physics performance.

scholarly journals Trigger Rate Monitoring Tools at CMS

2019 ◽  
Vol 214 ◽  
pp. 01047
Author(s):  
Andrew Wightman ◽  
Geoffrey Smith ◽  
Kelci Mohrman ◽  
Charles Mueller
Keyword(s):  
Event Rate ◽  
Trigger System ◽  
Level Trigger ◽  
Cms Experiment ◽  
Trigger Rate ◽  
Monitoring Tools ◽  
Pile Up ◽  
Overall Performance ◽  
Level 1 ◽  
High Level

One of the major challenges for the Compact Muon Solenoid (CMS)experiment, is the task of reducing event rate from roughly 40 MHz down to a more manageable 1 kHz while keeping as many interesting physics events as possible. This is accomplished through the use of a Level-1 (L1) hardware based trigger as well as a software based High-Level Trigger (HLT). Monitoring and understanding the output rates of the L1 and HLT triggers is of key importance for determining the overall performance of the trigger system and is intimately tied to what type of data is being recorded for physics analyses. We present here a collection of tools used by CMS to monitor the L1 and HLT trigger rates. One of these tools is a script (run in the CMS control room) that gives valuable real-time feedback of trigger rates to the shift crew. Another useful tool is a plotting library, that is used for observing how trigger rates vary over a range of beam and detector conditions, in particular how the rates of individual triggers scale with event pile-up.

scholarly journals Upgrade of the (barrel) muon trigger electronic system of the CMS experiment at CERN

2018 ◽  
Author(s):  
Νικήτας Λούκας
Keyword(s):  
Distribution System ◽  
Compact Muon Solenoid ◽  
Drift Tube ◽  
Electronic System ◽  
Muon Track ◽  
Muon Trigger ◽  
Control Distribution ◽  
Cms Experiment ◽  
Level 1 ◽  
And Control

Το σύστημα σκανδαλισμού του πειράματος “Συμπαγές Σωληνοειδές Μιονίων” (Compact Muon Solenoid, CMS) του Ευρωπαϊκού οργανισμού πυρηνικών ερευνών CERN (Conseil Européen pour la Recherche Nucléaire) αναβαθμίζεται συνεχώς έτσι ώστε να μπορεί να ανταπεξέλθει στην όλο και αυξανόμενη φωτεινότητα των αλληλεπιδράσεων αδρονιών. Η αναβάθμιση αυτή είναι προγραμματισμένο να γίνεται σε φάσεις, κατά τις οποίες το CMS διακόπτει την λειτουργία του. Οι φάσεις των αναβαθμίσεων του ηλεκτρονικού επιπέδου του συστήματος σκανδαλισμού (Level-1 Trigger, L1T) ξεκίνησαν το 2016 όπου και πραγματοποιήθηκε η πρώτη φάση αναβάθμισης. Το 2025 είναι προγραμματισμένο να συμβεί η δεύτερη φάση και στην συνέχεια ακολουθούν και άλλες φάσεις αναβαθμίσεων μετά το 2030. Τμήμα του πρώτου επιπέδου σκανδαλισμού (δηλαδή αυτού που απαρτίζεται από ηλεκτρονικές μονάδες επεξεργασίας) της πρώτης φάσης της αναβάθμισης του πειράματος CMS περιγράφεται στην παρούσα Διδακτορική Διατριβή. Το κεντρικό ή βαρελοειδές σύστημα εύρεσης τροχιών μιονίων (Barrel Muon Track Finder, BMTF) αποτελεί το βασικό αντικείμενο που συνοψίζεται στις επόμενες ενότητες, οι οποίες συμπληρώνονται από την παρουσίαση εργασίας που αφορά και περισσότερα τμήματα του συστήματος σκανδαλισμού L1T. Έτσι εκτός από το BMTF παρουσιάζεται και εργασία που αφορά τρία συστήματα συλλογής και διανομής δεδομένων: TwinMux, Pre-Processing and Fan-out (CPPF) και AMC502. Καθώς επίσης και αξιολόγηση καλής λειτουργίας ηλεκτρονικών καρτών οι οποίες χρησιμοποιήθηκαν στο σύστημα ελέγχου και διανομής χρονισμού (Timing and Control Distribution System, TCDS). Ο αλγόριθμος του BMTF αναπτύχθηκε με βάση αυτόν που λειτουργούσε έως το τέλος 2015 στο παλαιότερο σύστημα σκανδαλισμού το οποίο ονομάζεται Drift Tube Track Finder (DTTF). Στο νέο σύστημα, ο αλγόριθμος παρουσίασε ικανοποιητική απόδοση που επιβεβαιώθηκε μέσω συγκρίσεων που έγιναν με την απόδοση συστήματος απομίμησης του αλγόριθμου ανεπτυγμένου σε λογισμικό. Κατά την διάρκεια της συναρμολόγησης του συστήματος στο πείραμα εγκαταστάθηκαν ηλεκτρονικές κάρτες, οπτικές ίνες αλλά και οπτικά μέσα, τμήμα των οποίων αντικαταστάθηκε λόγω μη ικανοποιητικής λειτουργίας τους. Κατά τις πρώτες δοκιμές το σύστημα παρουσίασε προβλήματα τα οποία λύθηκαν μέσα στα χρονικά περιθώρια που είχαν τεθεί και έτσι το BMTF τέθηκε σε πλήρη λειτουργία πριν το πείραμα CMS επαναλειτουργήσει για το 2016.

scholarly journals Recording and reconstructing 10 billion unbiased b hadron decays in CMS

2020 ◽  
Vol 245 ◽  
pp. 01025
Author(s):  
Robert Bainbridge
Keyword(s):  
Data Stream ◽  
High Efficiency ◽  
Data Set ◽  
Level Trigger ◽  
Cms Experiment ◽  
Trigger Strategy ◽  
Reconstruction Performance ◽  
Level 1 ◽  
High Level ◽  
New Algorithms

The CMS experiment has recorded a high-purity sample of 10 billion unbiased b hadron decays. The CMS trigger and data acquisition systems were configured to deliver a custom data stream at an average throughput of 2 GB s−1, which was “parked” prior to reconstruction. The data stream was defined by level-1 and high level trigger algorithms that operated at peak trigger rates in excess of 50 and 5 kHz, respectively. New algorithms have been developed to reconstruct and identify electrons with high efficiency at transverse momenta as low as 0.5 GeV. The trigger strategy and electron reconstruction performance were validated with pilot processing campaigns. The accumulation and reconstruction of this data set, now complete, were delivered without significant impact on the core physics programme of CMS. This unprecedented sample provides a unique opportunity for physics analyses in the flavour sector and beyond.

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