Lucio Fidel Rebolledo Herrera

arXiv2022

Performance of BeBe, a proposed dedicated beam-beam monitoring detector for the MPD-NICA experiment at JINR

The Multipurpose Detector (MPD) is an experimental array, currently under construction, designed to study the nuclear matter created during the collisions that will be provided by the Nuclotron-based Ion Collider fAcility (NICA) at JINR. The MPD-NICA experiment consists of a typical array of particle detectors as those used to study heavy-ion collisions at LHC and RHIC. To increase the trigger capabilities of MPD for stage 2 of NICA operation, a detector conformed by two arrays of 80 plastic scintillator cells each located symmetrically at opposite sides of the interaction point of MPD is proposed (BeBe). Based on Monte Carlo simulations, a discussion of the potential physics performance of BeBe detector is given for triggering tasks and for the resolution in the determination of the event plane reaction and the centrality of the collisions at NICA. Also, laboratory measurements to estimate the time resolution of individual BeBe cells prototypes are presented. It is shown that a time resolution between 0.65 and 1.48 ns can be reached depending on the number of photosensors employed to collect the scintillation photons. The BeBe detector will be complementary to FFD and FHCAL forward detectors.

physics.ins-det↗

arXiv2021

Intrinsic time resolution and efficiency characterization for two size of BC-404 plastic scintillators studies in Geant4

The time resolution (TR) is one of the most important characteristic of a detector. For the case of a scintillator, the collection of light also is important, it depends of the effective area of the photo-sensor (\textit{Scorer}). The Photomultipliers Tubes (PMTs), normally, have an effective area greater than the Silicon Photomultipliers (SiPMs), however, due to its voltage of operation, their size or cost, in some cases it can be difficult to work with them. In which case, it is preferable to use SiPMs. The value of TR also depends of the size and geometry of the scintillator, number of photo-sensors and the electronic part.\\ In this work, we study the mean optical photon arrival time distribution (AT) to a Scorer from a SiPM of 6$\times$6~mm$^2$. We define the variation of AT as \textit{the intrinsic time resolution} (ITR). In Geant4, we simulated two different geometries: square and hexagonal, for a BC-404 plastic scintillator coupled to one Scorer. The sources simulated were Sr$^{90}$, Co$^{60}$, Cs$^{137}$, Na$^{22}$ and $μ^-$ of 1~GeV. It is shown that AT and ITR depends of the geometry and size of the plastic scintillator, the location of the Scorer, the incident particle and its energy. Then, the ITR and therefore the TR is not a constant for a detector. Finally, we show the relation between AT and the deposited energy by the particle incident, which are related in the experiment to the response time event of the detector and the deposited charge by the incident particle, respectively.

physics.ins-det↗