12.6.2020 The Fast Interaction Trigger for the ALICE Upgrade (Slupecki)

The design of complex particle detection system, that meets strict accuracy and reliability requirements, is a complex multi-layer project. The doctoral thesis of Maciej Slupecki deals with the Fast Interaction Trigger detector to be used in the upgraded ALICE experiment at the Large Hadron Collider at CERN. The thesis presents the research and development of the detector that is now in the final production stage and will be commissioned in 2021.
Published
12.6.2020

Fundamental research is the driving force for our civilization and any technological advancements that improve the quality of our lives. One of the fundamental topics studied by Particle Physics is related to the quarks, that are the smallest building blocks of known matter, and the interactions between them.

In a similar way to water, that transforms from liquid into a gaseous form when heated up, the behaviour of quarks changes when the temperature and pressure changes. Upon reaching 2 trillion (2x1012 ) degrees Centigrade any ordinary matter melts into a new state called Quark-Gluon Plasma. A Large Ion Collider Experiment (ALICE) at CERN is dedicated to studying transition and properties of this exotic state of matter.

To reach such high temperatures the Large Hadron Collider at CERN accelerates and smashes together nuclei of atoms.

“We can create only minute quantities of the Plasma, that are extremely short-lived, quickly cool down and transform back into ordinary matter in a form of various kinds of particles flying outwards from the collision region. By registering the properties of outgoing particles we try to understand the behaviour of the Plasma they originated from”, Maciej Slupecki says.

ALICE experiment at CERN is composed of many types of highly-specialized subdetectors. One of them is the Fast Interaction Trigger. It is designed to provide very prompt signal (trigger) to the other subsystems about the quality and type of the collision.

“We expect up to a few millions collisions per second in ALICE during normal LHC operation and this trigger information is crucial to decide if the data from a given collision should be analysed and recorded by ALICE as a whole. Additionally, this trigger is used to help adjust the particle beams to reach optimal collision parameters.”

The research and development has been challenging because of the harsh operational conditions and extensive requirements for the detector to perform well.

“We have built and tested several prototypes utilizing two technologies, the Cherenkov and scintillation effects. The test results helped to gradually improve the design. In parallel, we have verified with computer simulations how the design tuning affects the detector performance. Altogether, the research has been very versatile with a major focus on programming, related to simulations and data analysis, accompanied by elements of electronics, optics and mechanics”, Maciej Slupecki remarks.

The research is published in JYU Dissertation series, number 235, Jyväskylän yliopisto, Jyväskylä, 2020. ISBN 978-951-39-8186-0 (PDF), URN:ISBN:978-951-39-8186-0, ISSN 2489-9003

Link to the publication:

M.Sc. Maciej Slupecki defends his doctoral dissertation in Physics "The Fast Interaction Trigger for the ALICE Upgrade" on Friday June 12, 2020 starting at 12 noon. Opponent Professor is Agnieszka Zalewska from Polish Academy of Sciences and Custos is Docent Wladyslaw Trzaska from the Ģֱ. The doctoral dissertation is held in English.

The dissertation is held online. Link to the Zoom Webinar (Zoom application or Google Chrome web browser recommended): 
Password: 643066