2 research outputs found
On the application of differences in intrinsic fluctuations of Cherenkov light images for separation of air showers
The sensitivity of ground-based imaging atmospheric Cherenkov gamma-ray
observatories depends critically on the primary particle identification methods
which are used to retain photon-initiated events and suppress the spurious
background produced by cosmic rays. We suggest a new discrimination technique
which utilizes differences in the fluctuations of the light intensity in the
images of showers initiated by photons and those initiated by protons or
heavier nuclei. The database of simulated events for the proposed VERITAS
observatory has been used to evaluate the efficiency of the new technique.
Analysis has been performed for both a single VERITAS imaging telescope, and a
system of these telescopes. We demonstrate that a discrimination efficiency of
> 1.5 - 2.0 can be achieved in addition to traditional background rejection
methods based on image shape parameters.Comment: 17 pages, 9 figures, accepted for publucation in Astropart. Phy
On the Potential of the Imaging Atmospheric Cherenkov Technique for Study of the Mass Composition of Primary Cosmic Radiation in the Energy Region above 30 TeV
We suggest a new approach to study the cosmis ray (CR) mass composition in
the energy region from 30 TeV/nucleus up to the "knee" region, i.e. up to a few
PeV/nucleus, using an array of imaging atmospheric Cherenkov telescopes (IACTs)
of a special architecture. This array consists of telescopes with a relatively
small mirror size (~10 square meters) separated from each other by large
distances (~500 meters) and equipped by multichannel cameras with a modest
pixel size (0.3-0.5 degree) and a sufficiently large viewing angle (6-7
degree).
Compared to traditional IACT systems (like HEGRA, HESS or VERITAS) the IACT
array considered here could provide a very large detection area (several square
kilometers or more). At the same time, it allows an accurate measurement of the
energy of CR induced air showers (the energy resolution ranges within 25-35%)
and an effective separation of air showers created by different nuclei.
Particularly, it is possible to enrich air showers belonging to the nucleus
group assigned for selection up to ~90% purity at a detection efficiency of
15-20% of such showers.Comment: 28 pages, 12 figures, accepted for publication in Nucl. Instr. Met