Passage Of Cosmic Rays Research Articles

Design, Construction, Test, Operation and Simulation of a Four Channel Cosmic Ray Detector

Cosmic ray detectors are constructed to fit many purposes, different materials and geometries. To test materials and to measure the flux of cosmic rays, we planned, designed, constructed, tested and operated a 4 channel cosmic ray detector based on 2.54 cm X 10.32 cm X 20.64 cm Aluminum block and two 0.6 cm X 10.32 cm X 20.64 cm plastic scintillators completely covered with 0.2 cm thick Aluminum foil. The signal, produced by the passage of cosmic rays, was read out using a Hamamatsu photomultiplier in both the Aluminum block and plastic scintillator. The performance of this detector was simulated using GEANT 4. The efficiency of the cosmic ray detector was measured to give 85% approximately. Details of construction, operation, simulation, and preliminary results are presented.

Cosmic rays observed by the resonant gravitational wave detector NAUTILUS

The passage of cosmic rays has been observed to excite mechanical vibrations in the resonant gravitational wave detector NAUTILUS operating at temperature of 100 mK. A very significant correlation (more than 10 standard deviations) is found.

A study of ionization electrons drifting over large distances in liquid argon

We have measured the lifetime of electrons drifting in liquid argon using a gridded ionization chamber with a drift gap of 153 mm. The electrons were produced by the passage of cosmic rays through the chamber. We find a best fit for the electron lifetime τ at 5 V/cm of 9.2 ms (with 13.2 > τ > 7.1 ms at 95% CL). This value is consistent with all the data below 15 V/cm. This corresponds to an impurity concentration ρ = 0.03 ppb oxygen equivalent. The attenuation length calculated from the above lifetime is 18 m for a field of 1 kV/cm. The liquid remained in the chamber for 14 weeks with no recirculation system and suffered no noticeable deterioration with respect to the lifetime or the pulse height. The low field mobility μ 0 has been measured for fields up to 150 V/cm and we find a value of 545 ± 4 cm 2 V −1 s −1 which is consistent with measurements by other authors. The electron yield as a function of the electric field strength has been measured down to 3 V/cm. The results seem to indicate the need for a modification of the geminate recombination theory.

Cosmic ray flashes in the eye.

THE observations by Apollo astronauts of light flashes in the eye during lunar flights have been interpreted by Fazio et al.1 as Cerenkov radiation. These authors have also considered the possibility of direct stimulation of the retinal cells by the passage of cosmic rays. I wish to show that the observed effects can also be interpreted as scintillations produced in the eye lens by the passage of multiply charged cosmic rays.

ČCerenkov radiation of extensive air showers

Short light flashes superimposed on the buckground of the night sky glow, correlated with the passage of cosmic rays in the atmosphere, were first detected in 1952. It was established that at least some of these flashes were caused by Cherenkov radiation of extensive air showers. Further experiments were condncted in the Pamir mountains (altitude 356 m) in the autumn of 1955. The purpose of this investigation wss to study the lateral distribation of the light flux relative to the core of the showers and also to determine the relation between the intensity of the light flashes and the size of the shower. The experimental arrangement included an optical receiver that registered the light flashes and a Geiger counter hodoscope. Two series of measurements were made. The semsitivity of the light receivers was adfusted so that about 100 pulses per hour were registered. On an average, each flash was accompanied by triggering of 20 hodoscope counters, while the number of cases when no counter was triggered was 4%. Thus it was established that pactically all light flashes of a given intensity were produced by extensive air showers. (A.C.)

Solar corpuscular streams and cosmic ray variations

The idea that corpuscular streams of highly ionized neutral matter, effected by the sun, may lead to variations of cosmic rays of extrasolar origin is due to Alfven. The idea was further developed by Brunberg and by Trumpy and applied successfully to a particular case of crossed telescope observations by Elliott and Dolebear. This idea in its original form has lost popularity. There is evidence that the passage of cosmic rays through an average strearn actually gives variations on earth with exactly the kind of spectrum necessary to explain diurnal variations. (A.C.)