arXiv subjects

R. Privara

Publications and source records attributed to R. Privara.

4 recordsLinked to original sources

arXiv2026

The study of gamma-radiation induced displacement damage in $n^+$-in-$p$ silicon diodes

The bulk damage of $p$-type silicon sensors caused by gamma irradiation with high total ionizing doses has been investigated. The study was carried out on different types of $n^+$-in-$p$ silicon diodes with different oxygen concentrations and silicon bulk resistivities. The Secondary-Ion Mass Spectrometry technique was used to determine the relative concentration of oxygen in the individual samples. The measured diodes were irradiated by a $^{60}$Co gamma source to total ionizing doses ranging from 0.50 up to 8.28 MGy, and annealed for 80 minutes at 60{\deg}C. The main goal of the study was to characterize the gamma-radiation induced displacement damage by measuring IV and CV characteristics, and the evolution of the full depletion voltage with the total ionizing dose. The Transient Current Technique was used to verify the full depletion voltage and to extract the electric field distribution and the sign of the space charge in the silicon diodes irradiated to the lowest and the highest delivered total ionizing doses. The results show a linear increase of the bulk leakage current with the total ionizing dose, with the damage coefficient being dependent on initial resistivity and oxygen concentration of the silicon diode. The effective doping concentration and full depletion voltage decrease significantly with an increasing total ionizing dose, before starting to increase again at a specific dose. We assume that the initial decrease in the effective doping concentration is caused by the effect of acceptor removal. An additional notable finding of this study is that the bulk leakage current and CV characteristics of the gamma-irradiated diodes do not show any evidence of an annealing effect.

hep-ex↗

arXiv2026

CORSIKA 8: A General Framework for Particle Cascade Simulations

The simulation of extensive air showers and particle cascades in general is a cornerstone of modern astroparticle physics. For more than two decades, CORSIKA, currently in version 7, has been one of the most widely used tools for this purpose. However, its architecture reflects design constraints of an earlier computing era, as well as increasingly limiting extensibility, maintainability, and adaptability to modern experimental requirements. CORSIKA 8 is a complete redesign of the original CORSIKA code, implemented in modern C++ and based on contemporary software engineering principles. It introduces a modular and extensible simulation framework with explicit handling of units, flexible geometry, and environment descriptions. In this paper, we present the design philosophy and core architecture of CORSIKA 8, describe the implementation of electromagnetic and hadronic shower physics, and validate air shower simulations against CORSIKA 7. The results demonstrate good agreement at the few-percent level for key observables, confirming the physics fidelity of CORSIKA 8. We also showcase new use cases that were beyond the capabilities of version 7, such as the simulation of cross-media showers and particle cascades in ice, including radio-signal propagation

astro-ph.IM↗

arXiv2023

Study of Bulk Damage of High Dose Gamma Irradiated p-type Silicon Diodes with Various Resistivities

The bulk damage of p-type silicon detectors caused by high doses of gamma irradiation has been studied. The study was carried out on three types of n$^{+}$-in-p silicon diodes with comparable geometries but different initial resistivities. This allowed to determine how different initial parameters of studied samples influence radiation-induced changes in the measured characteristics. The diodes were irradiated by a Cobalt-60 gamma source to total ionizing doses ranging from 0.50 up to 8.28 MGy, and annealed for 80 minutes at 60 {\deg}C. The Geant4 toolkit for simulation of the passage of particles through matter was used to simulate the deposited energy homogeneity, to verify the equal distribution of total deposited energies through all the layers of irradiated samples, and to calculate the secondary electron spectra in the irradiation box. The main goal of the study was to characterize the gamma-radiation induced displacement damage by measuring current-voltage characteristics (IV), and the evolution of the full depletion voltage with the total ionizing dose, by measuring capacitance-voltage characteristics (CV). It has been observed that the bulk leakage current increases linearly with total ionizing dose, and the damage coefficient depends on the initial resistivity of the silicon diode. The effective doping concentration and therefore full depletion voltage significantly decreases with increasing total ionizing dose, before starting to increase again at a specific dose. We assume that this decrease is caused by the effect of acceptor removal. Another noteworthy observation of this study is that the IV and CV measurements of the gamma irradiated diodes do not reveal any annealing effect.

physics.ins-det↗

arXiv2023

Test beam measurement of ATLAS ITk Short Strip module at warm and cold operational temperature

This study is focused on an investigation of the performance of the Short Strip module developed by the ATLAS Inner Tracker (ITk) strip collaboration using electron beams of energy 5.4 GeV and 5.8 GeV at the DESY-II Testbeam Facility. The noise at +30 C and -30 C was measured. The ratio of the two measurements is compared with a circuit-model calculation. The measured noise at -30 C is compared with the maximum noise that would correspond to an acceptable signal-to-noise ratio after the expected radiation damage from operation at HL-LHC. The measured charge distributions at +30 C and -30 C are compared with GEANT4 simulations. The detection efficiency and noise-occupancy were measured as a function of threshold at both +30 C and -30 C. The average cluster width was measured as a function of threshold. Scans of detection efficiency versus threshold at different delay settings were used to reconstruct the pulse shape in time. The resulting pulse shape was compared with a circuit model calculation.

hep-ex↗