Detection Of Cosmic-ray Showers Research Articles

Development of scintillator detector for detection of cosmic ray shower

An array of plastic scintillator detectors is proposed for detection of cosmic ray showers at an altitude of about 2200 meters above sea level in the Himalayas at the Centre for Astroparticle Physics & Space Sciences, Darjeeling campus of Bose Institute. Each element of this array is a 1 m × 1 m plastic scintillator detector of thickness 2 cm, coupled with WLS fibers and a PMT. During the first phase seven of these modules arranged in an hexagonal way keeping one at the centre of the hexagon will be commissioned. Four such modules have already been built and tested. As a proof of principle three of these detectors are used to detect cosmic ray shower. The preliminary results are presented.

Microwave detection of cosmic ray showers at the Pierre Auger Observatory

Microwave emission from the electromagnetic cascade induced in the atmosphere by ultra-high energy cosmic rays (UHECR) may allow for a novel detection technique, which combines the advantages of the well-established fluo- rescence technique - the reconstruction of the shower profil e - with a 100% duty cycle, minimal atmospheric attenuation and the use of low-cost commercial equipment. Two complementary techniques are currently being pursued at the Pierre Auger Observatory. AMBER (Air-shower Microwave Bremsstrahlung Experimental Radiometer), MIDAS (Microwave Detection of Air Showers) and FDWave are prototypes for a large imaging dish antenna. In EASIER (Extensive Air Shower Identification using Electron Radiometer), the micr owave emission is detected by antenna horns located on each surface detector of the Auger Observatory. MIDAS is a self-triggering system while AMBER, FDWave, and EASIER use the trigger from the Auger detectors to record the emission. The coincident detection of UHECR by the microwave prototype detectors and the fluorescence and surface detect ors will prove the viability of this novel technique. The sta tus of microwave R&D activities at the Pierre Auger Observatory will be reported.

Towards the installation and use of an extended array for cosmic ray detection: The EEE Project

The Extreme Energy Events (EEE) project started to use an array of cosmic ray telescopes for muon detection, distributed over the italian territory. The use of such telescopes, based on Multigap Resistive Plate Chambers (MRPC) allows the study of the local muon flux, the detection of cosmic ray showers and the search for correlations between distant showers. The project is also intended to involve high school teams in an advanced research work. The present status of the installation and the first physics results are discussed here.

Prospects for radio detection of ultra-high energy cosmic rays and neutrinos

The origin and nature of the highest energy cosmic ray events is currently the subject of intense investigation by giant air shower arrays and fluorescent detectors. These particles reach energies well beyond what can be achieved in ground-based particle accelerators and hence they are fundamental probes for particle physics as well as astrophysics. One of the main topics today focuses on the high energy end of the spectrum and the potential for the production of high-energy neutrinos. Above about 10 20 eV cosmic rays from extragalactic sources are expected to be severely attenuated by pion photoproduction interactions with photons of the cosmic microwave background. Investigating the shape of the cosmic ray spectrum near this predicted cut-off will be very important. In addition, a significant high-energy neutrino background is naturally expected as part of the pion decay chain which also contains much information. Because of the scarcity of these high-energy particles, larger and larger ground-based detectors have been built. The new generation of digital radio telescopes may play an important role in this, if properly designed. Radio detection of cosmic ray showers has a long history but was abandoned in the 1970s. Recent experimental developments together with sophisticated air shower simulations incorporating radio emission give a clearer understanding of the relationship between the air shower parameters and the radio signal, and have led to resurgence in its use. Observations of air showers by the SKA could, because of its large collecting area, contribute significantly to measuring the cosmic ray spectrum at the highest energies. Because of the large surface area of the moon, and the expected excellent angular resolution of the SKA, using the SKA to detect radio Cherenkov emission from neutrino-induced cascades in lunar regolith will be potentially the most important technique for investigating cosmic ray origin at energies above the photoproduction cut-off.

Preliminary evaluation of the installation cost for a > 1019eV array in Basilicata

Abstract In this paper we discuss the logistic problems related to the installation of an array for the detection of cosmic ray showers with energies > 10 19 eV in a populated area. As an example we have taken the province of Potenza in Basilicata, Italy. In this province we have selected an area of ∼ 3,000 km 2 with an altitude 400 – 1,2000 m.a.s.l. , where the detectors could be located. Taking as an example an array grid spacing of 3 km , we have tentatively located on the map the detectors and evaluated the detailed cost of the connection to electricity and telephone lines. The result of this exercise is very encouraging, showing the advantage of locating an array in a mildly populated area, where power and data networks are already available.

A long-distance coincidence radio-pulse experiment

Three radio receiving stations, operating at 45, 70, and 70 MHz center frequencies, have been set up for air shower detection. Separations are 10, 12, and 20 km between stations. Pulses are selected by combinations of antennae pointing towards magnetic west at large zenith angles. In 1 000 hours of operation, about 150 events have been observed in excess of the random expectation over the 10-km distance. Over the 12-km separation, no excess has been observed in 244 hours, but operation is restricted in this case by intervening hills to zenith angles less than 84°. Over the 20-km separation, a small excess is observed, which may be due to chance. In a series of subsidiary experiments, radio pulses have been correlated with night-sky Cerenkov detectors and a scintillation counter, and with receivers at 12, 35, and 500 Mc/s. From these experiments the rate of detection of cosmic-ray showers at a single station is believed to be at least 1 per hour, or about 5–10% of the radio pulses selected. Local radio coincidences at individual stations are in excess of random expectation, and the pulse-height spectrum for local events is steeper than would be expected for cosmic-ray events or interference pulses. The long-distance coincidences have not been established directly as cosmic-ray events, but are consistent with this interpretation.