Neutron production by cosmic-ray particles at sea level and underground

1951 ◽  
Vol 8 (5) ◽  
pp. 326-340 ◽  
Author(s):  
R. D. Sard ◽  
M. F. Crouch ◽  
D. R. Jones ◽  
A. M. Conforto ◽  
B. F. Stearns

1949 ◽  
Vol 76 (8) ◽  
pp. 1134-1136 ◽  
Author(s):  
R. D. Sard ◽  
A. M. Conforto ◽  
M. F. Crouch


1951 ◽  
Vol 6 (11) ◽  
pp. 592-598
Author(s):  
N. Adams ◽  
H. J. J. Braddick

AbstractWe have measured the barometer coefficient of cosmic ray neutron production at sea level and find the value -9,25% ± 0,20/cmHg. We have shown that there is no diurnal variation of neutron production of amplitude greater than about 0,4 %. The effects of the large solar flare of November 19 th , 1949 on cosmic ray neutrons were much greater than on ionising cosmic rays at sea level; the maximum factor of increase was more than 5 and the intensity remained measurably above normal for about 12 hours. A small increase of neutron intensity is found, statistically, to be correlated with a number of recorded radio fade-outs. It is suggested that neutron measurements are particularly suitable for studying temporal variations of cosmic rays. The latitude increase of cosmic ray neutrons between geomagnetic latitude 54,5° and 56,5° was found to be about 2%. No certain increase was found between 56,5° and 59,5°.





1970 ◽  
Vol 3 (1) ◽  
pp. 6-8 ◽  
Author(s):  
O. C. Allkofer ◽  
P. Knoblich


2019 ◽  
Vol 5 (3) ◽  
pp. 54-58
Author(s):  
Анна Луковникова ◽  
Anna Lukovnikova ◽  
Виктор Алешков ◽  
Viktor Aleshkov ◽  
Алексей Лысак ◽  
...  

During three summer months in 2015, the Cosmic Ray (CR) station Irkutsk-3000, located at 3000 m above sea level, measured the CR neutron component intensity with the 6NM64 neutron monitor, as well as the atmospheric electric field strength and the level of electromagnetic interference during lightning discharges. It is shown that the level of electromagnetic interference, when registered during lightning discharges, depends considerably on the fixed level of signal discrimination. During observations, we observed no effects of thunderstorm discharges at the neutron monitor count rate at the CR station Irkutsk-3000.



1964 ◽  
Vol 32 (6) ◽  
pp. 1524-1540 ◽  
Author(s):  
S. Miyake ◽  
V. S. Narasimham ◽  
P. V. Ramana Murthy
Keyword(s):  


1949 ◽  
Vol 2 (2) ◽  
pp. 184
Author(s):  
CBO Mohr

The structure of cosmic ray air showers at sea-level has been studied by an investigation of the burst rate frequency and the transition effect in lead, for cosmic ray bursts occurring simultaneously in two high-pressure ionization chambers with varying separation. Although extensive showers were responsible for all the coincidences observed with the larger chamber separations, they accounted for less than 3 per cent, of the bursts observed with a single chamber. Of the remaining 97 per cent., somewhat more than one-half appear to be due to nuclear disintegrations and the rest either to narrow showers of approximate radius 30 cm. or to the core of an extensive shower of low density. The extensive shower frequency was about 10 times that predicted by theory. The bearing of these results on present views of the origin and development of air showers is discussed.





2020 ◽  
pp. 1-15
Author(s):  
Pierfrancesco Mastinu ◽  
Dario Bisello ◽  
Rogelio Alfonso Barrera ◽  
Ignacio Porras ◽  
Gianfranco Prete ◽  
...  

In this contribution we describe NEPIR, the fast-neutron irradiation facility under construction at the 70 MeV cyclotron SPES facility of the INFN laboratory of Legnaro (LNL). NEPIR will be constructed in stages, according to the available funds. The initial configuration, based on a thick Be neutron production target, will be operational in 2022; it will be used for shielding studies against fast neutrons for space applications and to investigate neutron-induced Single Event Effects (SEE) in microelectronic devices and systems. In its final configuration NEPIR will have two target systems: one will deliver a Quasi Mono-energetic Neutron (QMN) beam, of general interest, with an adjustable energy peak in the 20–70 MeV range; the second target will deliver a specialized continuous energy neutron beam for studying the effects of fast neutrons produced in cosmic ray air-showers in electronic devices and systems. We review the use of NEPIR to characterize the sensitivity of electronics, describe the neutron production targets and the facility layout. In closing we describe ways, presently under investigation, to use the 15 MV XTU Tandem of LNL to produce nearly monochromatic fast neutrons that would complement the QMN system by allowing one to probe for SEE below 20 MeV.



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