Relazione sulle attività svolte nel Corso del
dottorato
Marco Francesconi, XXXII Ph.D. Cycle
Supervisors: Alessandro Baldini Donato Nicolò
I spent my Ph.D. working with the MEG group of INFN of Pisa, at the frontline of the experiment upgrade at Paul Scherrer Institut (PSI) in Switzerland. The collaboration is pretty small ~60
researchers from 5 countries, allowing me to have a key role in the experimental collaboration as part of the TDAQ Crew. The Trigger and Data Acquisition (TDAQ) item is shared between INFN sez. Pisa and PSI so, for a big part of the three years, I stayed at the host laboratory to tightly
collaborate with other collaborators.
Working with the TDAQ is a good place to keep in touch all the different detector and items composing the experimental setup having a complete view of the experiment and all its components.
1st year
Attended Ph.D. courses:
• “Fisica delle alte energie”, 50 hours, University of Pisa in collaboration with INFN of Pisa and Scuola Normale Superiore, Final assessment: 95%
• “Analisi statistica dei dati”, 40 hours, University of Pisa, Final assessment: 95% • “Fisica della materia”, 40 hours, University of Pisa, Final assessment: 100% • “Scientific Writing”, 10 hours, University of Pisa
Student seminar:
21-09-17 “Improving hadrotherapy with FOOT experiment” Overall first year final evalutation: ottimo
Research activities abroad:
From 05/12/16 to 16/12/16 Paul Scherrer Institut (CH) MEG II Pre-engineering run 2016
From 04/06/17to 15/06/16 Paul Scherrer Institut (CH) MEG II Liquid Xenon detector commissioning
From 07/05/17-10/05/17 Centro Protonterapia (Trento) Test beam for the FOOT experiment
Conferences:
13/09/17 “Stato dell’esperimento MEG II” Talk in parallel session, Congresso SIF, Trento Workshops:
26/03/17-31/03/17, Lepton Flavor Physics with Most Intense DC Muon Beams, Tokyo (JP) Talk on Montecarlo based trigger simulations
2nd year
Student seminar (Pre-thesis):
22-10-18 “Online event selection for the MEG II Experiment” Overall second year final evalutation: ottimo
Research activities abroad: From 06/11/17-24/11/17 and
From 04/12/17-24/12/17 Paul Scherrer Institut (CH) MEG II Pre-engineering run 2017
Conferences: 30/05/18
“Low latency serial communication for MEG II trigger system” Poster, Pisa Meeting on Advanced Detectors, La Biodola (IT) 10/06/18
“The WaveDAQ integrated Trigger and Data Acquisition System for the MEG II experiment” Talk in plenary session, IEEE NPSS Real-Time 2018, Colonial Williamsburg VA (USA)
Workshops:
03/04/18-09/04/18, Global Developments of Researches in Lepton Flavor Physics with Muons, Tokyo (JP)
Talk on Trigger status
06/06/18-08/06/18, Global Developments of Researches in Lepton Flavor Physics with Muons, Paul Scherrer Institut (CH)
Talk on Trigger status
3rd year
Research activities abroad (continued from previous year): From 01/05/18-18/09/19 Paul Scherrer Institut (CH)
Continuous on-field presence for Trigger commissioning and support to Drift Chamber commissioning (financiary support from INFN and “Borsa Angelo della Riccia”)
Workshops:
19/03/19-21/03/19, Global Developments of Researches in Lepton Flavor Physics with Muons, Tokyo (JP)
Thesis Title:
The new trigger and data acquisition system for LFV searches in the MEG II experiment Thesis summary:
The MEG II experiment aims at a factor 10 improvement in the branching ratio limit of the muon to electron plus photon decay; it follows the path traced by its previous phase (known as MEG I) which already produced the world best upper limit of <= 4.2 10^-13 @ 90% C.L. The new
experimental apparatus is currently in its commissioning phase at Paul Scherrer Institute in Switzerland.
In this thesis a novel Trigger and Data acquisition (TDAQ) system, named WaveDAQ, is described with the goal of fulfilling the requirements of the experiment upgrade, the most stringent one being the readout of ~8000 channels at GHz speeds. The single event size will be therefore in the order of 12 MB without any compression or zero-supperession, thus a very selective yet efficient online event selection needs to be operated to maintain the throughput at a reasonable level (< 24 Hz).
The first results of the new apparatus in 2018 and 2019 pre-engineering run are reported validating the full design of the TDAQ system toward its final production in 2020.
Having the capabilities to increase the the event speed in dedicated runs up to few 100 Hz, exotic Lepton Flavor Violating channels in reach of MEG II are presented and sensitivity on the muon to electron plus invisible was studied. Results show a very huge effect of momentum scale
uncertainty on the measurement which needs to be fixed below the 5 keV/c level in order for MEG II to be competitive with current limits of ~10^-5 by the TWIST collaboration.
Relevant publications:
Typology of
publication Authors Title References
Article A.M. Baldini et al.
The design of the MEG II
experiment. The European Physical Journal C 78.5 (2018): 380.
10.1140/epjc/s10052-018-5845-6 Article G. Boca et al. The laser-based time
calibration system for the MEG II pixelated Timing Counter.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated
Equipment 947 (2019): 162672. 10.1016/j.nima.2019.162672 Article M. Morrocchi et al. Development and characterization of a ΔE-TOF detector prototype for the FOOT experiment
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated
Equipment 916 (2019): 116-124.
10.1016/j.nima.2018.09.086 Proceeding L. Galli et al. WaveDAQ: An highly
integrated trigger and data acquisition system
Proceeding of Pisa Meeting on Advanced Detectors 2018
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated
Equipment 936 (2019): 399-400.
proceeding M. Francesconi et al.
Low latency serial communication for MEG II trigger system
Proceeding of Pisa Meeting on Advanced Detectors 2018
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated
Equipment 936 (2019): 331-332.
10.1016/j.nima.2018.09.153 proceeding S. Kobayashi et
al.
Precise measurement of 3D-position of SiPMs in the liquid xenon gamma-ray detector for the MEGII
experiment.
Proceeding of Pisa Meeting on Advanced Detectors 2018
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated
Equipment 936 (2019): 189-191.
10.1016/j.nima.2018.10.170 proceeding M. Chiappini et
al.
The new drift chamber of the MEG II experiment
Proceeding of Pisa Meeting on Advanced Detectors 2018
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated
Equipment 936 (2019): 501-502.
10.1016/j.nima.2018.10.182 proceeding M. Nishimura et
al.
Full system of positron timing counter in MEG II
having time resolution below 40 ps with fast plastic scintillator readout by SiPMs
Proceeding of Vienna Conference on Instrumentation 2019
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated
Equipment 958 (2020): 162785.
10.1016/j.nima.2019.162785
Two articles currently in process of publication:
D.Nicolò et al., “Real-time particle identification in liquid Xenon”, submitted to NIMA T.Libeiro et al., “X-Ray scanning technique for Alignment of Photosensor”, internal review
Other activities:
I took part to 11 MEG II Collaboration meeting over the three years with talks on Trigger and Data Acquisition commissioning status.
I was present at three “Open User Meeting” (editions 2017, 2018 and 2019) organized by LTP-NUM department of PSI (CH).
I gave one presentation to INFN referees experiment in the TDAQ status as substitute for the INFN responsible researcher.
The code I developed to handle the MEG II readout is currently being used also by the FOOT experiment.
In the last year I started contributing to the development of Midas DAQ software
(http://midas.triumf.ca), which is the backend of MEG II TDAQ and is used by several others experiment.
