Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userThe FLASH Thick Target Experiment: Direct Measurement of Air Fluorescence Yield in Electromagnetic Showers
70
0
0.0
(
0
)
Authors
J. Belz
Ask ChatGPT about the research
No Arabic abstract
A key assumption in the reconstruction of extensive air showers using the air fluorescence technique is the hypothesis that fluorescence is proportional to energy deposition at all depths in the shower. This ansatz, along with the supposition that particle distribution and energy loss can be well modeled by modern shower simulation software, must be thoroughly verified in order to validate the air fluorescence technique. We report here the results of the first direct measurement of air fluorescence yield as a function of shower depth, as performed in the thick-target phase of the FLASH (FLuorescence in Air from SHowers) experimental program at the SLAC Final-Focus Test Beam facility. We compare observed fluorescence light yields as a function of shower depth to concurrently measured charged particle yields, to the predictions of the EGS and GEANT software packages, and to empirical energy-loss models. We also examine the extent to which the relative yield versus shower depth is independent of wavelength within the fluorescence spectrum.
rate research
Read More
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.
In a test experiment at the Final Focus Test Beam of the Stanford Linear Accelerator Center, the fluorescence yield of 28.5 GeV electrons in air and nitrogen was measured. The measured photon yields between 300 and 400 nm at 1 atm and 29 deg C are Y(760 Torr, air) = 4.42 +/- 0.73 and Y(760 Torr, nitrogen) = 29.2 +/- 4.8 photons per electron per meter. Assuming that the fluorescence yield is proportional to the energy deposition of a charged particle traveling through air, good agreement with measurements at lower particle energies is observed.
Horizon-T is an innovative detector system constructed to study Extensive Air Showers (EAS) in the energy range above 10^16 eV coming from a wide range of zenith angles (0 - 85 degrees). The system is located at Tien Shan high-altitude Science Station of Lebedev Physical Institute of the Russian Academy of Sciences at approximately 3340 meters above the sea level. It consists of eight charged particle detection points separated by the distance up to one kilometer as well as optical detector subsystem to view the Vavilov-Cerenkov light from the EAS. The time resolution of charged particles and Vavilov-Cerenkov light photons passage of the detector system is a few ns. This level of resolution allows conducting research of atmospheric development of individual EAS.
The determination of the shower development in air using fluorescence yield is subject to corrections due to the angular spread of the particles in the shower. This could introduce systematic errors in the energy determination of an extensive air shower through the fluorescence technique.
Inclined air showers - those arriving at ground with zenith angle with respect to the vertical theta > 60 deg - are characterised by the dominance of the muonic component at ground which is accompanied by an electromagnetic halo produced mainly by muon decay and muon interactions. By means of Monte Carlo simulations we give a full characterisation of the particle densities at ground in ultra-high energy inclined showers as a function of primary energy and mass composition, as well as for different hadronic models assumed in the simulations. We also investigate the effect of intrinsic shower-to-shower fluctuations in the particle densities.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
