CERN Accelerating science

Article
Report number	arXiv:1512.08014
Title	MPX Detectors as LHC Luminosity Monitor
Author(s)	Sopczak, Andre (IEAP CTU, Prague) ; Ali, Babar (IEAP CTU, Prague) ; Asbah, Nedaa (Montreal U.) ; Bergmann, Benedikt (IEAP CTU, Prague) ; Bekhouche, Khaled (Biskra U.) ; Caforio, Davide (IEAP CTU, Prague) ; Campbell, Michael (CERN) ; Heijne, Erik (IEAP CTU, Prague) ; Leroy, Claude (Montreal U.) ; Lipniacka, Anna (Bergen U.) ; Nessi, Marzio (CERN) ; Pospisil, Stanislav (IEAP CTU, Prague) ; Seifert, Frank (IEAP CTU, Prague) ; Solc, Jaroslav (IEAP CTU, Prague) ; Soueid, Paul (Montreal U.) ; Suk, Michal (IEAP CTU, Prague) ; Turecek, Daniel (IEAP CTU, Prague) ; Vykydal, Zdenek (IEAP CTU, Prague)
Publication	2015
Imprint	25 Dec 2015
Number of pages	17
Note	Comments: Presented at the IEEE 2015 Nuclear Science Symposium, San Diego, USA
In:	IEEE Trans. Nucl. Sci. 62 (2015) pp.3225-3241
In:	2015 IEEE Nuclear Science Symposium and Medical Imaging Conference, San Diego, CA, USA, 31 Oct - 7 Nov 2015
DOI	10.1109/TNS.2015.2496316
Subject category	Detectors and Experimental Techniques
Accelerator/Facility, Experiment	CERN LHC ; ATLAS
Abstract	A network of 16 Medipix-2 (MPX) silicon pixel devices was installed in the ATLAS detector cavern at CERN. It was designed to measure the composition and spectral characteristics of the radiation field in the ATLAS experiment and its surroundings. This study demonstrates that the MPX network can also be used as a self-sufficient luminosity monitoring system. The MPX detectors collect data independently of the ATLAS data-recording chain, and thus they provide independent measurements of the bunch-integrated ATLAS/LHC luminosity. In particular, the MPX detectors located close enough to the primary interaction point are used to perform van der Meer calibration scans with high precision. Results from the luminosity monitoring are presented for 2012 data taken at sqrt(s) = 8 TeV proton-proton collisions. The characteristics of the LHC luminosity reduction rate are studied and the effects of beam-beam (burn-off) and beam-gas (single bunch) interactions are evaluated. The systematic variations observed in the MPX luminosity measurements are below 0.3% for one minute intervals.
Copyright/License	arXiv nonexclusive-distrib. 1.0 publication: © 2016-2024 The Author(s) (License: CC-BY-3.0)

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