A long-distance coincidence radio-pulse experiment

1968 ◽  
Vol 46 (10) ◽  
pp. S250-S254 ◽  
Author(s):  
D. J. Fegan ◽  
B. McBreen ◽  
E. P. O'Mongain ◽  
N. A. Porter ◽  
P. J. Slevin
Keyword(s):  
Radio Pulse ◽  
Scintillation Counter ◽  
Pulse Height ◽  
Cosmic Ray ◽  
Pulse Height Spectrum ◽  
Long Distance ◽  
Pulse Experiment ◽  
Single Station ◽  
Random Expectation ◽  
Set Up

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.

Cosmic-ray proton and helium spectra and solar modulation effects in the new solar cycle measured with a four-element counter telescope

1968 ◽  
Vol 46 (10) ◽  
pp. S883-S886 ◽  
Author(s):  
J. F. Ormes ◽  
W. R. Webber
Keyword(s):  
Scintillation Counter ◽  
Pulse Height ◽  
Cosmic Ray ◽  
Geometrical Factor ◽  
Solar Modulation ◽  
Primary Proton ◽  
Before And After ◽  
Order Of Magnitude ◽  
Helium Spectra ◽  
Counter Telescope

In the summers of 1965 and 1966 we have continued our studies begun in 1963 on the primary proton and helium spectra and the effects of solar modulation. Data are available from four additional balloon flights at Fort Churchill using the earlier version of the Cerenkov-scintillation counter telescope (Ormes and Webber 1966), and a new four-element double-scintillation (dE/dx), Cerenkov-scintillation + range telescope. This latest telescope employs pulse-height analysis on both dE/dx counters and the Cerenkov-scintillation counter. Various consistency requirements may be set between pulse heights. These serve to reduce background effects by an order of magnitude over the previous system. The geometrical factor of the telescope is 55.4 sr cm2. The results reported here will cover the proton and helium spectra from 100 MeV/nucleon to 2 BeV/nucleon and their time variation. They will show that the fractional changes in the differential proton spectra can be represented by (rigidity)−1 both before and after the sunspot minimum and that there is no evidence for any hysteresis effects between protons of 100 MeV to 2 BeV and energies to which neutron monitors respond.

RADIO DETECTION OF COSMIC RAYS WITH LOPES

2006 ◽  
Vol 21 (supp01) ◽  
pp. 168-181 ◽  
Author(s):  
A. HORNEFFER ◽  
W. D. APEL ◽  
F. BADEA ◽  
L. BÄHREN ◽  
K. BEKK ◽  
...  
Keyword(s):  
Radio Pulse ◽  
Pulse Height ◽  
Cosmic Ray ◽  
Radio Interference ◽  
Air Showers ◽  
Digital Radio ◽  
Radio Receivers ◽  
Air Shower ◽  
Radio Detection ◽  
Digital Radio Receivers

Measuring radio pulses from cosmic ray air showers offers various new opportunities. New digital radio receivers allow measurements of these radio pulses even in environments that have lots of radio interference. With high bandwidth ADCs and fast data processing it is possible to store the whole waveform information in digital form and analyse transient events like air showers even after they have been recorded. Digital filtering and beam forming can be used to suppress the radio interference so that it is possible to measure the radio pulses even in radio loud environments. LOPES is a prototype station for the new digital radio interferometer LOFAR and is tailored to measure air showers. For this it is located at the site of the KASCADE-Grande air shower experiment. Already with the first phase of LOPES we have been able to measure radio pulses from air showers and show correlations between the radio pulse height and air shower parameters. The first part gives an introduction and presents the science results of LOPES, while the second part presents the hard- and software that enables LOPES to detect air short pulses.

A LARGE-AREA LIQUID SCINTILLATION COUNTER AND SOME MEASUREMENTS ON HIGH-ENERGY COSMIC-RAY PARTICLES

1958 ◽  
Vol 36 (1) ◽  
pp. 54-72 ◽  
Author(s):  
C. H. Millar ◽  
E. P. Hincks ◽  
G. C. Hanna
Keyword(s):  
Energy Loss ◽  
Liquid Scintillation ◽  
Scintillation Counter ◽  
Pulse Height ◽  
Central Area ◽  
Cosmic Ray ◽  
High Energy ◽  
Liquid Scintillation Counter ◽  
Height Distribution ◽  
Half Maximum

A liquid scintillation counter is described which consists of a [Formula: see text] in. by [Formula: see text] in. by 2 in. Plexiglas tank of terphenyl plus α-naphthylphenyloxazole (αNPO) in triethylbenzene. The tank is surrounded by MgO powder and viewed by a total of eight RCA Type 5819 photomultiplier tubes along two opposite edges. For normally incident fast μ-mesons a peaked pulse height distribution is observed, 20.5% in width at half-maximum for the central area of the counter, broadening to 25–30% at the perimeter, and estimated to be 25% over-all. When the Landau distribution in energy loss (width 18% at half-maximum) and the geometric spread are taken into account, a counter resolution function 8% in width at half-maximum is obtained for the central area of the counter, or 18% for the counter as a whole.The most probable pulse height for 0.30 Bev. μ-mesons is 1.6 ± 0.5% higher than for 2.2 Bev. μ-mesons, in close agreement with the Bethe–Bloch theory as extended by Symon and with a density correction calculated by the method of Sternheimer. Pulse heights from protons in the region 0.3 to 0.8 Bev. vary directly with the theoretically computed energy loss in the counter. Peak position and resolution are unchanged by a flux of 12 mr./hr. of thorium γ-rays.

Cosmic Ray Induced Photomultiplier Noise

1976 ◽  
Vol 3 (1) ◽  
pp. 38-39
Author(s):  
A. G. Gregory ◽  
R. W. Clay
Keyword(s):  
Cosmic Rays ◽  
Pulse Height ◽  
Cosmic Ray ◽  
High Amplitude ◽  
High Energy ◽  
Cerenkov Radiation ◽  
Pulse Height Spectrum ◽  
Noise Pulse ◽  
High Energy Cosmic Rays ◽  
Glass Envelope

Cosmic rays produce a component of photomultiplier noise which often dominates the high amplitude region of the noise pulse height spectrum and which is not reduced by cooling the tube. The source of the noise is Cerenkov radiation produced by individual high energy cosmic rays in their passage through the glass envelope of the tube, principally in the glass faceplate on which the photocathode is deposited.

scholarly journals In-Line Analysis of Diffusion Processes in Micro Channels by Long Distance Raman Photometric Measurement Technology—A Proof of Concept Study

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 116
Author(s):  
Julian Deuerling ◽  
Shaun Keck ◽  
Inasya Moelyadi ◽  
Jens-Uwe Repke ◽  
Matthias Rädle
Keyword(s):  
Numerical Aperture ◽  
Spot Size ◽  
Measuring System ◽  
Optical Systems ◽  
Measurement Technology ◽  
Long Distance ◽  
Measuring Point ◽  
Acetone Concentration ◽  
Micro Channels ◽  
Set Up

This work presents a novel method for the non-invasive, in-line monitoring of mixing processes in microchannels using the Raman photometric technique. The measuring set-up distinguishes itself from other works in this field by utilizing recent state-of-the-art customized photon multiplier (CPM) detectors, bypassing the use of a spectrometer. This addresses the limiting factor of integration times by achieving measuring rates of 10 ms. The method was validated using the ternary system of toluene–water–acetone. The optical measuring system consists of two functional units: the coaxial Raman probe optimized for excitation at a laser wavelength of 532 nm and the photometric detector centered around the CPMs. The spot size of the focused laser is a defining factor of the spatial resolution of the set-up. The depth of focus is measured at approx. 85 µm with a spot size of approx. 45 µm, while still maintaining a relatively high numerical aperture of 0.42, the latter of which is also critical for coaxial detection of inelastically scattered photons. The working distance in this set-up is 20 mm. The microchannel is a T-junction mixer with a square cross section of 500 by 500 µm, a hydraulic diameter of 500 µm and 70 mm channel length. The extraction of acetone from toluene into water is tracked at an initial concentration of 25% as a function of flow rate and accordingly residence time. The investigated flow rates ranged from 0.1 mL/min to 0.006 mL/min. The residence times from the T-junction to the measuring point varies from 1.5 to 25 s. At 0.006 mL/min a constant acetone concentration of approx. 12.6% was measured, indicating that the mixing process reached the equilibrium of the system at approx. 12.5%. For prototype benchmarking, comparative measurements were carried out with a commercially available Raman spectrometer (RXN1, Kaiser Optical Systems, Ann Arbor, MI, USA). Count rates of the spectrophotometer surpassed those of the spectrometer by at least one order of magnitude at identical target concentrations and optical power output. The experimental data demonstrate the suitability and potential of the new measuring system to detect locally and time-resolved concentration profiles in moving fluids while avoiding external influence.

Coupling a scintillator to a small photosensitive area

1969 ◽  
Vol 47 (19) ◽  
pp. 2125-2127 ◽  
Author(s):  
J. M. Daniels ◽  
Laura Y. C. Tsui
Keyword(s):  
Refractive Index ◽  
Linear Function ◽  
Scintillation Counter ◽  
Pulse Height

A model is developed to describe a scintillation counter coupled to a photosensitive area which is small in comparison with the dimensions of the scintillator. It is shown that the reciprocal of the pulse height is a linear function of the reciprocal of the photosensitive area, and that the constants in this relation are determined by the albedo of the material surrounding the scintillator and by the refractive index of the medium coupling the window to the photosensitive device. This relation has been verified experimentally.

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