arXiv subjects

C. H. Zepeda-Fernández

Publications and source records attributed to C. H. Zepeda-Fernández.

3 recordsLinked to original sources

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↗

arXiv2024

Statistical analysis of IUVB values in Mexico City from 2000 to 2022

The solar radiation are electromagnetic waves, composed of infrared, visible spectrum and ultraviolet. The infrared component is the cause of thermal energy, the visible spectrum allows to see and the ultraviolet component is the most energetic part and dangerous for the human body (skin and eyes). The ultraviolet rays are divided in a wavelength range, in three parts; called UVA (100-280 nm), UVB (280-315 nm) and UVC (315-400 nm). The UVC are the most energetic (followed by the UVB rays ), however are stopped in the ozone layer. In this work it shown a statistical analysis of the UVB index measured by five station in Mexico City, from the years 2000 to 2022. Through a Gaussian fit distribution, it was found that the range when the IUVB value exceeds the value of seven, which is from 11:00 to 16:00, having an average mean value of 13:09 hrs. $\pm$ 4 min. i.e. the time at which the UVB index reaches its maximum value. This occurs in the months from February to October. More than 80% of radiation is for UVB values less than 7 and less than the remaining 20% is for IUVB values greater than 7. Finally, it was possible to observe that the mean value per year, reaches its maximum when the solar cycles occurs, which was in the years 2003 and 2013.

physics.space-ph↗

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↗