On the Cherenkov light produced at several observatory altitudes by extensive air showers in the energy range 0.01-10 TeV

Portocarrero, C E; Arqueros, F.

doi:10.1088/0954-3899/24/1/026

Cited by 6 publications

(12 citation statements)

References 19 publications

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“…The hump is made by photons coming from depths around the shower maximum. For γ cascades, the influence of the limited FOV on the calculated average lateral density distribution is observed at impact parameters larger than the hump position and it is almost negligible for lower impacts, consistent with [4].…”

Section: The Lateral Density Distribution Of Cherenkov Photonssupporting

confidence: 82%

“…The average shower size is a linear function of energy in all MC sets and both simulated primary particles as shown in [9]. The results of the γ MC set III are consistent with those presented in [4] while I take into account that in [4] they were calculated from photons having zenith angles smaller than 1.4 o and are within a radius of 150 m. These two conditions may explain the non-linear dependence and different influence of the observation altitude on the shower sizes, which are presented in [4] for primary protons. As can be seen in Figure 4b the expected total number of Cherenkov photons, which were not absorbed and have zenith angles belov 2.5 o , is aproximately the same on both simulated observation levels.…”

Section: Shower Size Fluctuationssupporting

confidence: 81%

“…The hump observed in γ-rays (figure 7c) is closer to the core axis for observation levels of 4 km due to a geometrical effect -the distance between the shower maximum and observation altitude is smaller. At this level, also the density decreases faster for impact parameters beyond the hump position, while close to the core axis higher densities are observed for the same primary energy, as shown in [3,4]. This effect was expected, since the average shower size is almost the same on the both simulated observation levels.…”

Section: The Lateral Density Distribution Of Cherenkov Photonssupporting

confidence: 61%

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Limits to the energy resolution of a single air Cherenkov telescope at low energies

Sobczyńska¹

2009

J. Phys. G: Nucl. Part. Phys.

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Abstract. The photon density on the ground is a fundamental quantity in all experiments based on Cherenkov light measurements, e.g. in the Imaging Air Cherenkov Telescopes (IACT). IACT's are commonly and successfully used in order to search and study Very High Energy (VHE) γ-ray sources. Difficulties with separating primary photons from primary hadrons (mostly protons) in Cherenkov experiments become larger at lower energies. I have calculated longitudinal and lateral density distributions and their fluctuations at low energies basing on Monte Carlo simulations (for vertical γ cascades and protonic showers) to check the influence of the detector parameters on the possible measurement. Relative density fluctuations are significantly higher in proton than in photon induced showers. Taking into account the limited detector field of view (FOV) implies the changes of these calculated distributions for both types of primary particles and causes an enlargement in relative fluctuations. Absorption due to Rayleigh and Mie scattering has an impact on mean values but does not change relative fluctuations. The total number of Cherenkov photons is more sensitive to the observation height in γ cascades than in proton showers at low primary energies. The relative fluctuations of the density do not depend on the reflector size in the investigated size range (from 240 m 2 up to 960 m 2 ). This implies that a single telescope with a mirror area larger than that of the MAGIC telescope cannot achieve better energy resolution than estimated and presented in this paper. The correlations between longitudinal and lateral distributions are much more pronounced for primary γ-ray than for primary proton showers.PACS numbers: 95.55. Ka;95.55.Vj;95.85.Pw;95.85.Ry

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Section: The Lateral Density Distribution Of Cherenkov Photonssupporting

confidence: 82%

Section: Shower Size Fluctuationssupporting

confidence: 81%

Section: The Lateral Density Distribution Of Cherenkov Photonssupporting

confidence: 61%

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Limits to the energy resolution of a single air Cherenkov telescope at low energies

Sobczyńska¹

2009

J. Phys. G: Nucl. Part. Phys.

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“…As a result, the lateral distribution ofČerenkov photons has been known to change with the altitude of the observation level. The core distance at which the hump appears as well as the prominence of the hump will be smaller with increasing altitude of observation [37,38]. Since theČerenkov front is being intercepted at different observation levels during its propagation in the atmosphere, the shower parameters like the average arrival angle, time etc also will be different at different observation levels.…”

Section: Altitude Dependence Of Quality Factorsmentioning

confidence: 99%

Possible discrimination between gamma rays and hadrons using Čerenkov photon timing measurements

Chitnis

Bhat

2001

Astroparticle Physics

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AtmosphericČerenkov Technique is an established methodology to study T eV energy gamma rays. However the challenging problem has always been the poor signal to noise ratio due to the presence of abundant cosmic rays. Several ingenious techniques have been employed to alleviate this problem, most of which are centred around theČerenkov image characteristics. However there are not many techniques available for improving the signal to noise ratio of the data from wavefront sampling observations. One such possible technique is to use theČerenkov photon arrival times and identify the species dependent characteristics in them. Here we carry out systematic monte carlo simulation studies of the timing information ofČerenkov photons at the observation level. We have parameterized the shape of theČerenkov shower front as well as the pulse shapes in terms of experimentally measurable quantities. We demonstrate the sensitivity of the curvature of the shower front, pulse shape parameters as well as the photon arrival time jitter to primary species and show their efficiency in improving the signal to noise ratio. The effect of limiting theČerenkov telescope opening angle by using a circular focal point mask, on the efficacy of the parameters has also been studied for each of the parameters. Radius of the shower front, pulse decay time and photon arrival time jitter have been found to be the most promising parameters which could be used to discriminate γ−ray events from the background. We also find that the efficiency of the first two parameters increases with zenith angle and efficiency of pulse decay time decreases with increasing altitude of observation.

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“…Rizo-Patrón- Boylan & Aljovín de Losada, 1998;Rizo-Patrón-Boylan, 2000;Kogan, 2009) y otros la clase media (e.g. Portocarrero 1998;Gamero & Zeballos, 2003;Plaza 2007), Alarcón se concentró en el estudio de la pobreza, uno de los fenómenos más distintivos de la realidad peruana (Alarcón, 1986).…”

Section: El Trabajo De Reynaldo Alarcónunclassified

La contribución de Reynaldo Alarcón al desarrollo y fortalecimiento de la psicometría en el Perú

Léon

2014

Rev. Investig. Psicol.

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RESUMENEn la presente comunicación se revisa a las contribuciones de Reynaldo Alarcón al desarrollo de la tradición psicométrica en el Perú. Formado bajo la dirección de Walter Blumenfeld, el psicólogo alemán que emigrara al Perú, Alarcón ha desarrollado a lo largo de toda su carrera una activa labor de investigación, en la cual ha estandarizado pruebas psicológicas para nuestro medio y ha explorado aspectos de la mentalidad de los peruanos por medio de inventarios y cuestionarios. Su manual de técnicas de investigación es un libro de excelente factura. Además, se comenta su actual interés por la psicología positiva y, dentro de ella, sus estudios sobre la felicidad.Palabras clave: Reynaldo Alarcón, tests, inventarios, Perú. ABSTRACT REYNALDO ALARCON CONTRIBUTION TO DEVELOPMENT AND STRENGTHENING OF PSYCHOMETRICS IN PERUIn this communication the author reviews the contributions of Reynaldo Alarcón to the psychometric tradition in the psychology of Peru. A former student of Walter Blumenfeld, the German psychologist emigrated to Peru in the 1930´s, Alarcón is author of a number of investigations in which he standardized questionnaires and inventories and intelligence tests, and explored aspects of the mentality of Peruvians. His text on research techniques and designs is a book of excellent quality. In the frame of this communication the author comments Alarcón's interest for positive psychology, and his recent papers on psychology of happiness.

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On the Cherenkov light produced at several observatory altitudes by extensive air showers in the energy range 0.01-10 TeV

Cited by 6 publications

References 19 publications

Limits to the energy resolution of a single air Cherenkov telescope at low energies

Limits to the energy resolution of a single air Cherenkov telescope at low energies

Possible discrimination between gamma rays and hadrons using Čerenkov photon timing measurements

La contribución de Reynaldo Alarcón al desarrollo y fortalecimiento de la psicometría en el Perú

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