CERN Accelerating science

Thesis
Report number	CERN-THESIS-2021-025
Title	Fabrication and characterization of ultra-high level radiation sensors with thin-film nanolayers
Related title	Κατασκευή και χαρακτηρισµός αισθητήρων ακτινοβολίας υπερυψηλών επιπέδων (ultra high-level radiation) µε τη χρήση λεπτών µεταλλικών νανο-υµενίων
Author(s)	Meskova, Viktoria (Democritus University of Thrace (GR))
Publication	105.
Thesis note	Diploma : Democritus University of Thrace : 2021-03-16
Thesis supervisor(s)	Ravotti, Federico ; Sidiropoulou, Ourania ; Sallese, Jean-Michel ; Farmakis, Filippos
Note	Presented 24 Mar 2021
Subject category	Engineering ; Detectors and Experimental Techniques
Accelerator/Facility, Experiment	CERN PS
Abstract	In high energy physics experiments it is a common practice to expose detectors, electronic components and systems to particle beams, in order to assess their level of radiation tolerance and reliability. One of the facilities used for such tests is the Proton Irradiation Facility (IRRAD) which is located at the CERN accelerator complex. In order to properly control the 24 GeV/c proton beam and guarantee reliable results during the irradiation tests in IRRAD, Beam Profile Monitor (BPM) devices are used. The current BPMs are manufactured according to standard PCB technology featuring a matrix of copper sensing pads. When exposed to the beam, secondary electrons are emitted from each pad generating a charge proportional to the particle flux. The charge is measured individually for each pad using a dedicated readout system, and thus the shape, the position and the intensity of the beam are obtained. This thesis presents the study carried out for the improvement of BPM devices and the development of a new fabrication technique, based on microfabrication. The new prototypes that were manufactured have more efficient structure with better sensing material, substrate and design. More specifically, they are one order of magnitude thinner (less invasive), they present higher sensitivity due to the usage of aluminum as sensing material which has, intrinsically, higher secondary electron yield than copper and they have enhanced radiation tolerance. The performance of the new BPMs was tested with 200 MeV electron beam in the CLEAR facility at CERN, to validate their functionality and to investigate their usability in lower energy electron beams (MeV) for general-purpose applications (e.g, industry, medicine). Key words: Beam-line instrumentation, secondary electron emission (SEE), radiation-hard detectors, secondary electron yield (SEY), micro-fabrication, thin-films

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