Tagging single muons and other long-flying relativistic charged particles by ultra-fast timing in air Cherenkov telescopes

Abstract

Atmospheric air Cherenkov telescopes are successfully used for ground-based, very high-energy (VHE) gamma ray astronomy. Triggers from the so-called single muon and other long-flying relativistic charged particle events are an unwanted background for the Cherenkov telescope. Because of low rate at TeV energies the muon background is unimportant. It is much more intense for telescopes with high photon sensitivity and low energy threshold. Below a few hundred GeV energy, the so-called muon background becomes so intense, that it can deteriorate the sensitivity of telescopes (the so-called muon-wall problem). From general considerations it can be anticipated that the signature of these particles should be a light pulse with a narrow time structure. In fact, simulations show that the pulses from muons have a very narrow time profile that is well below the time resolutions of nearly all currently operating telescopes. In this report we elaborate on the time profile of Cherenkov light from the so-called single muons and show that a telescope with ultra-fast time response can open a new dimension allowing one to tag and to reject those events.

arXiv commentAccepted by Astroparticle Physics

References in corpus (4)

• Tests of a Prototype Multiplexed Fiber-Optic Ultra-fast FADC Data Acquisition System for the MAGIC Telescope
• Simulation Studies on Arrival Time Distributions of Cherenkov Photons in Extensive Air Showers
• Measurable difference in Cherenkov light between gamma and hadron induced EAS
• Review of the Solar Array Telescopes

Cited by in corpus (10)

• Design Concepts for the Cherenkov Telescope Array
• Improving the performance of the single-dish Cherenkov telescope MAGIC through the use of signal timing
• Signal Reconstruction for the MAGIC Telescope
• Using Muon Rings for the Calibration of the Cherenkov Telescope Array: A Systematic Review of the Method and its Potential Accuracy
• Cosmic ray composition measurements and cosmic ray background free gamma-ray observations with Cherenkov telescopes
• Natural limit on the gamma/hadron separation for a stand alone air Cherenkov telescope
• Muons as a tool for background rejection in Imaging Atmospheric Cherenkov Telescope arrays
• Direct Comparison of SiPM and PMT Sensor Performances in a large-size imaging air Cherenkov telescope
• Background rejection using image residuals from large telescopes in imaging atmospheric Cherenkov telescope arrays
• The background from single electromagnetic subcascades for a stereo system of air Cherenkov telescopes