No Arabic abstract
MAGIC comprises two 17m diameter IACTs to be operated in stereo mode. Currently we are commissioning the second telescope, MAGIC II. The camera of the second telescope has been equipped with 1039 pixels of 0.1-degree diameter. Always seven pixels are grouped in a hexagonal configuration to form a cluster. This modular design allows easier control and maintenance of the camera. The pixel sensors are high quantum efficiency photomultiplier tubes (PMTs) from Hamamatsu (superbialkali type, QE ~ 32% at the peak wavelength) that we operate at rather low gain of 30 k. This allows us to also perform extended observations under moderate moonlight. The system of two MAGIC telescopes will at least double the sensitivity compared to MAGIC I and also will allow us to lower the energy threshold.Here we will report the performances of the Camera of the second MAGIC telescope.
The MAGIC 17m diameter Cherenkov telescope will be upgraded with a second telescope within the year 2007. The camera of MAGIC-II will include several new features compared to the MAGIC-I camera. Photomultipliers with the highest available photon collection efficiency have been selected. A modular design allows easier access and flexibility to test new photodetector technologies. The camera will be uniformly equipped with 0.1 degree diamter pixels, which allows the use of an increased trigger area. Finally, the overall signal chain features a large bandwidth to retain the shape of the very fast Cherenkov signals.
The Large-Sized Telescope (LST) prototype of the future Cherenkov Telescope Array (CTA) is located at the Northern site of CTA, on the Canary Island of La Palma. It is designed to provide optimal performance in the lowest part of the energy range covered by CTA, observing gamma rays down to energies of tens of GeV. The LST prototype started performing astronomical observations in November 2019 during the commissioning of the telescope and it has been taking data since then. In this contribution, we will present the tuning of the characteristics of the telescope in the Monte Carlo (MC) simulations to describe the data obtained, the estimation of its angular and energy resolution, and an evaluation of its sensitivity, both with simulations and with observations of the Crab Nebula.
Baikal-GVD is a km$^3$-scale neutrino telescope being constructed in Lake Baikal. Muon and partially tau (anti)neutrino interactions near the detector through the W$^{pm}$-boson exchange are accompanied by muon tracks. Reconstructed direction of the track is arguably the most precise probe of the neutrino direction attainable in Cerenkov neutrino telescopes. Muon reconstruction techniques adopted by Baikal-GVD are discussed in the present report. Performance of the muon reconstruction is studied using realistic Monte Carlo simulation of the detector. The algorithms are applied to real data from Baikal-GVD and the results are compared with simulations. The performance of the neutrino selection based on a boosted decision tree classifier is discussed.
In this contribution we describe the hardware, firmware and software components of the readout system of the MAGIC-II Cherenkov telescope on the Canary island La Palma. The PMT analog signals are transmitted by means of optical fibers from the MAGIC-II camera to the 80 m away counting house where they are routed to the new high bandwidth and fully programmable receiver boards (MONSTER), which convert back the signals from optical to electrical ones. Then the signals are split, one half provide the input signals for the level ONE trigger system while the other half is sent to the digitizing units. The fast Cherenkov pulses are sampled by low-power Domino Ring Sampler chips (DRS2) and temporarily stored in an array of 1024 capacitors. Signals are sampled at the ultra-fast speed of 2 GSample/s, which allows a very precise measurement of the signal arrival times in all pixels. They are then digitized with 12-bit resolution by an external ADC readout at 40 MHz speed. The Domino samplers are integrated in the newly designed mezzanines which equip a set of fourteen multi-purpose PULSAR boards. Finally, the data are sent through an S-LINK optical interface to a single computer. The entire DAQ hardware is controlled through a VME interface and steered by the slow control software program (MIR). The Data AcQuisition software program (DAQ) proceeds finally to the event building and data storage.
MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes sensitive above ~60 GeV, and located on the Canary Island of La Palma at the height of 2200 m.a.s.l. Since Autumn 2009 both telescopes are working together in stereoscopic mode. We use both Crab Nebula observations and Monte Carlo simulations to evaluate the performance of the system. Advanced stereo analysis allows MAGIC to achieve a sensitivity better than 0.8% of the Crab Nebula flux in 50 h of observations in the medium energy range (around a few hundred GeV). At those energies the angular resolution is better than 0.07{circ}, and the energy resolution is as good as 16%. We perform also a detailed study of possible systematics effects for the MAGIC telescopes.