IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
Beam-induced and cosmic-ray backgrounds observed in the ATLAS detector during the LHC 2012 proton-proton running period
Autor/es:
ATLAS; F. MONTICELLI
Revista:
JOURNAL OF INSTRUMENTATION
Editorial:
IOP PUBLISHING LTD
Referencias:
Lugar: Londres; Año: 2016
ISSN:
1748-0221
Resumen:
This paper discusses various observations on beam-induced and cosmic-ray backgrounds inthe ATLAS detector during the LHC 2012 proton-proton run. Building on published resultsbased on 2011 data, the correlations between background and residual pressure of the beamvacuum are revisited. Ghost charge evolution over 2012 and its role for backgrounds areevaluated. New methods to monitor ghost charge with beam-gas rates are presented andobservations of LHC abort gap population by ghost charge are discussed in detail. Fake jetsfrom colliding bunches and from ghost charge are analysed with improved methods, showingthat ghost charge in individual radio-frequency buckets of the LHC can be resolved. Someresults of two short periods of dedicated cosmic-ray background data-taking are shown; inparticular cosmic-ray muon induced fake jet rates are compared to Monte Carlo simulationsand to the fake jet rates from beam background. A thorough analysis of a particular LHCfill, where abnormally high background was observed, is presented. Correlations betweenbackgrounds and beam intensity losses in special fills with very high β∗are studied.