Speaker
Tomáš SÝKORA
(Institute of Particle and Nuclear Physics, Faculty of Mathematics & Physics, Charles University)
Description
The performance of the ATLAS Forward Proton Time-of-Flight (ToF)
Cherenkov detector is shown using the ATLAS collaboration data collected
in the 2017 running period of the LHC Run2. The detailed analysis of the
results, including detector efficiency and time resolution of the ToF is
performed.
The detector construction and its expected performance based on beam
tests results are briefly summarized at the beginning of the first part
of the talk. Operational experiences, problems caused due to attempts to
operate MCP-PMTs in the vacuum and leading to the change of the detector
construction, the request for R2D2 like construction of a new, future,
MCP-PMT due to the observed gain drop for high rates and its
non-recoverability are described. Also, other tested hardware changes
are presented – the effect of the replacement of non-monolithic by
monolithic crystal bars, the change of the MCP-PMT back-end electronics
based on simulation to reduce signal cross talk resulting in further
detector time resolution improvement.
The second part of the talk is devoted to the achieved time resolutions,
20 ± 4 ps and 26 ± 5 ps, of two installed ToF detectors. Despite of
their very low efficiencies (below 10%) in major parts of the analyzed
data, this represents a superb time resolution for detectors operating a
few millimeters from the LHC beams and making them, from the time
resolution point of view, the best ToF detector among those operated by
the different LHC experiments in the forward regions during the LHC
Run2. At the end the possibility of reconstruction of z-coordinate of
the ATLAS interaction region using the ToF detectors is shown.
Primary author
Tomáš SÝKORA
(Institute of Particle and Nuclear Physics, Faculty of Mathematics & Physics, Charles University)
