arXiv subjects

M. Iarlori

Publications and source records attributed to M. Iarlori.

7 recordsLinked to original sources

arXiv2018

The AMY (Air Microwave Yield) experiment to measure the GHz emission from air shower plasma

The aim of the Air Microwave Yield (AMY) experiment is to investigate the Molecular Bremsstrahlung Radiation (MBR) emitted from an electron beam induced air-shower. The measurements have been performed with a 510 MeV electron beam at the Beam Test Facility (BTF) of Frascati INFN National Laboratories in a wide frequency range between 1 and 20 GHz. We present the experimental apparatus and the first results of the measurements. Contrary to what have been reported in a previous similar experiment~\cite{Gorham-SLAC}, we have found that the intensity of the emission is strongly influenced by the particular time structure of the accelerator beam. This makes very difficult the interpretation of the emission process and a realistic extrapolation of the emission yield to the plasma generated during the development of an atmospheric shower.

astro-ph.IM↗

arXiv2017

Joint Elastic Side-Scattering Lidar and Raman Lidar Measurements of Aerosol Optical Properties in South East Colorado

We describe an experiment, located in south-east Colorado, USA, that measured aerosol optical depth profiles using two Lidar techniques. Two independent detectors measured scattered light from a vertical UV laser beam. One detector, located at the laser site, measured light via the inelastic Raman backscattering process. This is a common method used in atmospheric science for measuring aerosol optical depth profiles. The other detector, located approximately 40km distant, viewed the laser beam from the side. This detector featured a 3.5m2 mirror and measured elastically scattered light in a bistatic Lidar configuration following the method used at the Pierre Auger cosmic ray observatory. The goal of this experiment was to assess and improve methods to measure atmospheric clarity, specifically aerosol optical depth profiles, for cosmic ray UV fluorescence detectors that use the atmosphere as a giant calorimeter. The experiment collected data from September 2010 to July 2011 under varying conditions of aerosol loading. We describe the instruments and techniques and compare the aerosol optical depth profiles measured by the Raman and bistatic Lidar detectors.

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arXiv2013

The Air Microwave Yield (AMY) experiment - A laboratory measurement of the microwave emission from extensive air showers

The AMY experiment aims to measure the microwave bremsstrahlung radiation (MBR) emitted by air-showers secondary electrons accelerating in collisions with neutral molecules of the atmosphere. The measurements are performed using a beam of 510 MeV electrons at the Beam Test Facility (BTF) of Frascati INFN National Laboratories. The goal of the AMY experiment is to measure in laboratory conditions the yield and the spectrum of the GHz emission in the frequency range between 1 and 20 GHz. The final purpose is to characterise the process to be used in a next generation detectors of ultra-high energy cosmic rays. A description of the experimental setup and the first results are presented.

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arXiv2012

Precise measurement of the absolute fluorescence yield of the 337 nm band in atmospheric gases

A measurement of the absolute fluorescence yield of the 337 nm nitrogen band, relevant to ultra-high energy cosmic ray (UHECR) detectors, is reported. Two independent calibrations of the fluorescence emission induced by a 120 GeV proton beam were employed: Cherenkov light from the beam particle and calibrated light from a nitrogen laser. The fluorescence yield in air at a pressure of 1013 hPa and temperature of 293 K was found to be $Y_{337} = 5.61\pm 0.06_{stat} \pm 0.21_{syst}$ photons/MeV. When compared to the fluorescence yield currently used by UHECR experiments, this measurement improves the uncertainty by a factor of three, and has a significant impact on the determination of the energy scale of the cosmic ray spectrum.

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arXiv2011

Precise Measurement of the Absolute Yield of Fluorescence Photons in Atmospheric Gases

We have performed a measurement of the absolute yield of fluorescence photons at the Fermilab Test Beam. A systematic uncertainty at 5% level was achieved by the use of Cherenkov radiation as a reference calibration light source. A cross-check was performed by an independent calibration using a laser light source. A significant improvement on the energy scale uncertainty of Ultra-High Energy Cosmic Rays is expected.

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arXiv2007

Measurement of Aerosols at the Pierre Auger Observatory

The air fluorescence detectors (FDs) of the Pierre Auger Observatory are vital for the determination of the air shower energy scale. To compensate for variations in atmospheric conditions that affect the energy measurement, the Observatory operates an array of monitoring instruments to record hourly atmospheric conditions across the detector site, an area exceeding 3,000 square km. This paper presents results from four instruments used to characterize the aerosol component of the atmosphere: the Central Laser Facility (CLF), which provides the FDs with calibrated laser shots; the scanning backscatter lidars, which operate at three FD sites; the Aerosol Phase Function monitors (APFs), which measure the aerosol scattering cross section at two FD locations; and the Horizontal Attenuation Monitor (HAM), which measures the wavelength dependence of aerosol attenuation.

astro-ph↗

arXiv2007

The Lidar System of the Pierre Auger Observatory

The Pierre Auger Observatory in Malargue, Argentina, is designed to study the origin of ultrahigh energy cosmic rays with energies above 10^18 eV. The energy calibration of the detector is based on a system of four air fluorescence detectors. To obtain reliable calorimetric information from the fluorescence stations, the atmospheric conditions at the experiment's site need to be monitored continuously during operation. One of the components of the observatory's atmospheric monitoring system is a set of four elastic backscatter lidar stations, one station at each of the fluorescence detector sites. This paper describes the design, current status, standard operation procedure, and performance of the lidar system of the Pierre Auger Observatory.

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