Search results for " photons"

Calibration of the underground muon detector of the Pierre Auger Observatory

2021

To obtain direct measurements of the muon content of extensive air showers with energy above $10^{16.5}$ eV, the Pierre Auger Observatory is currently being equipped with an underground muon detector (UMD), consisting of 219 10 $\mathrm{m^2}$-modules, each segmented into 64 scintillators coupled to silicon photomultipliers (SiPMs). Direct access to the shower muon content allows for the study of both of the composition of primary cosmic rays and of high-energy hadronic interactions in the forward direction. As the muon density can vary between tens of muons per m$^2$ close to the intersection of the shower axis with the ground to much less than one per m$^2$ when far away, the necessary bro…

Characterization of a cylindrical plastic β-detector with Monte Carlo simulations of optical photons

2017

In this work we report on the Monte Carlo study performed to understand and reproduce experimental measurements of a new plastic β-detector with cylindrical geometry. Since energy deposition simulations differ from the experimental measurements for such a geometry, we show how the simulation of production and transport of optical photons does allow one to obtain the shapes of the experimental spectra. Moreover, taking into account the computational effort associated with this kind of simulation, we develop a method to convert the simulations of energy deposited into light collected, depending only on the interaction point in the detector. This method represents a useful solution when extens…

Phenol compounds as new materials for Electron Spin Resonance (ESR) dosimetry in clinical photon and electron beams

2015

In the last decades several research laboratories have shown an increasing interest aimed at extending the applicability of Electron Spin Resonance (ESR) dosimetry to radiotherapy with different types of radiation beams. ESR is a spectroscopic method for investigating the structure and dynamics of such paramagnetic species. Free radicals are known to be produced when a compound is irradiated with ionizing radiations. The concentration of radiation-induced free radicals is proportional to the energy released inside in the medium and this allows for dosimetric measurements through ESR technique which able to quantitatively determine the radical concentration.The use of alanine as a dosimetric…

Study of scintillation light collection, production and propagation in a 4 tonne dual-phase LArTPC

2020

The $3 \times 1 \times 1$ m$^3$ demonstrator is a dual phase liquid argon time projection chamber that has recorded cosmic rays events in 2017 at CERN. The light signal in these detectors is crucial to provide precise timing capabilities. The performances of the photon detection system, composed of five PMTs, are discussed. The collected scintillation and electroluminescence light created by passing particles has been studied in various detector conditions. In particular, the scintillation light production and propagation processes have been analyzed and compared to simulations, improving the understanding of some liquid argon properties.

Suora fotonituotto suurienergiaisissa ydintörmäyksissä sähkömagneettisen ja vahvan vuorovaikutuksen kertaluvussa O(α _em α_S)

2013

Experimental Engineering of Arbitrary Qudit States with Discrete-Time Quantum Walks

2019

The capability to generate and manipulate quantum states in high-dimensional Hilbert spaces is a crucial step for the development of quantum technologies, from quantum communication to quantum computation. One-dimensional quantum walk dynamics represents a valid tool in the task of engineering arbitrary quantum states. Here we affirm such potential in a linear-optics platform that realizes discrete-time quantum walks in the orbital angular momentum degree of freedom of photons. Different classes of relevant qudit states in a six-dimensional space are prepared and measured, confirming the feasibility of the protocol. Our results represent a further investigation of quantum walk dynamics in p…

Study of eta and eta' Photoproduction at MAMI

2017

The reactions γp→ηp and γp→η′p are measured from their thresholds up to the center-of-mass energy W=1.96 GeV with the tagged-photon facilities at the Mainz Microtron, MAMI. Differential cross sections are obtained with unprecedented statistical accuracy, providing fine energy binning and full production-angle coverage. A strong cusp is observed in the total cross section for η photoproduction at the energies in the vicinity of the η′ threshold, W=1896 MeV (Eγ=1447 MeV). Within the framework of a revised ηMAID isobar model, the cusp, in connection with a steep rise of the η′ total cross section from its threshold, can only be explained by a strong coupling of the poorly known N(1895)1/2− sta…

Thermoluminescence response of sodalime glass irradiated with photon and electron beams in the 1-20 Gy range

2011

Abstract The thermoluminescence response of a watch commercial glass was studied after irradiation with photons and electrons, in the range 1–20 Gy, of interest in accidental dosimetry; a linear response was obtained with both beams. This result, together with the satisfactory time stability of the thermoluminescence signal, indicates this glass as a potential material for retrospective dosimetry applications.

Triangular flow of thermal photons from an event-by-event hydrodynamic model for 2.76A TeV Pb + Pb collisions at the CERN Large Hadron Collider

2016

We calculate the triangular flow parameter v3 of thermal photons from an event-by-event ideal hydrodynamic model for 0–40% central collisions of Pb nuclei at √sNN = 2.76 TeV at the CERN Large Hadron Collider. v3 determined with respect to the participant plane (PP) is found to be nonzero and positive, and its pT dependence is qualitatively similar to the elliptic flow parameter v2(PP) of thermal photons in the range 1 pT 6 GeV/c. In the range pT 3 GeV/c, v3(PP) is found to be about 50–75% of v2(PP) and for pT > 3 GeV/c the two anisotropy parameters become comparable. The value of v3 is driven by local density fluctuations both directly via the creation of triangular geometry and indirectly …

The ALICE experiment at the CERN LHC

2008

Journal of Instrumentation 3(08), S08002 (2008). doi:10.1088/1748-0221/3/08/S08002