arXiv subjects

L. F. Rebolledo-Herrera

Publications and source records attributed to L. F. Rebolledo-Herrera.

3 recordsLinked to original sources

arXiv2026

Geant4 Simulation of an X-ray Beam Monitoring Detector based on plastic scintillators

Beam monitoring detectors play an important role in experimental control and radiological protection by enabling the real-time characterization of particle and photon beams. They provide information on beam intensity, position, and scattering, helping to ensure measurement accuracy, protect sensitive detectors, and quantify stray radiation in the surrounding environment. In this work, a Geant4 simulation was developed to investigate the performance of an X-ray beam monitoring detector (BMD) composed of six hexagonal BC404 plastic scintillators arranged to provide high granularity, using a reflector with a realistic reflectivity of 93\%. Under the simulation conditions considered in this study, the detector exhibited an intrinsic time resolution of 100.8 $\pm$ 2.0~ps. The results indicated that only about 10\% of the incident photons interacted with the detector, suggesting that the proposed design could be used for beam characterization while minimally perturbing the primary beam. In addition, the X-ray multiplicity decreased with distance according to an inverse-square dependence. A backscatter study performed using a water phantom showed that approximately 6\% of the incident beam was detected as scattered radiation. These results suggest that the proposed detector may be a useful tool for X-ray beam characterization and for studies related to scatter radiation and radiological protection. Further experimental validation is required to confirm these findings.

physics.med-ph↗

arXiv2026

Intrinsic time resolution of a hexagonal BC404 scintillator: A Monte Carlo study of interaction geometry and optical reflectivity

Time resolution is an important parameter in particle detectors, as it determines their ability to distinguish between two temporally separated events. It can be decomposed into electronic and intrinsic contributions, the latter being influenced by scintillation, optical transport, detector geometry, particle type and energy, and the sensitive area of the photosensor. In this work, a Monte Carlo simulation based on Geant4 is used to investigate the intrinsic time resolution of a hexagonal BC404 plastic scintillator. The analysis includes the evaluation of the optical-photon distribution over the hexagonal surfaces and the characterization of the intrinsic time resolution for different interaction configurations. The intrinsic time resolution is investigated using muons as cosmic-ray proxies with energies ranging from 4~GeV to 1~TeV. In addition, the effect of surface reflectivity on optical-photon transport and timing performance is studied for reflectivities ranging from 0\% to 100\%. The results show that the intrinsic time resolution exhibits little dependence on the incident muon energy, while a clear dependence on the interaction position is observed. Furthermore, although the number of detected photons varies with the interaction position and surface reflectivity, the intrinsic time resolution is not solely determined by photon statistics, indicating that optical transport and geometrical effects play an important role in the timing performance. Across the investigated configurations, intrinsic time resolutions ranging from approximately 15 to 100~ps are obtained. These findings highlight the importance of the interaction position, optical transport, photon statistics, and surface reflectivity in determining the timing performance of hexagonal plastic scintillators and provide guidance for the optimization of their optical properties and geometry for timing-sensitive applications.

physics.ins-det↗

arXiv2020

Electric charge estimation using a SensL SiPM

The silicon photo-multipliers (SiPMs) are commonly used in the construction of radiation detectors such as those used in high energy experiments and its applications, where an excellent time resolution is required for triggering. In most of this cases, the trigger systems electric charge information is discarded due to limitations in data acquisition. In this work we propose a method using a simple radiation detector based on an organic plastic scintillator $2\times2\times0.3$~cm$^3$ size, to estimate the electric charge obtained from the acquisition of the fast output signal of a SensL SiPM model C-60035-4P-EVB. Our results suggest a linear relation between the reconstructed electric charge from the fast output of the SiPM used with respect to the one reconstructed with its standard signal output. Using our electric charge reconstruction method, we compared the sensitivity of two plastic scintillators, BC404 and BC422Q, under the presence of Sr90, Cs137, Co60, and Na22 radiation sources.

physics.ins-det↗