High-Pressure Ionization Chamber Filled with BF3 Operating as a Neutron Counter

2006 ◽  
Author(s):  
Mieczyslaw Zielczynski ◽  
Natalia Golnik ◽  
Zdzislaw Rusinowski ◽  
Piotr Tulik
Keyword(s):  
High Pressure ◽  
Ionization Chamber ◽  
Neutron Counter

High-pressure xenon cylindrical ionization chamber with a shielding mesh

1994 ◽  
Author(s):  
Sergey E. Ulin ◽  
Valery V. Dmitrenko ◽  
V. M. Grachev ◽  
O. N. Kondakova ◽  
S. V. Krivov ◽  
...  
Keyword(s):  
High Pressure ◽  
Ionization Chamber ◽  
Cylindrical Ionization Chamber

scholarly journals Secondary gamma rays excited by the passage of neutrons through matter

1935 ◽  
Vol 150 (871) ◽  
pp. 637-668 ◽  
Keyword(s):  
High Pressure ◽  
Gamma Rays ◽  
Alpha Particle ◽  
Ionization Chamber ◽  
Gamma Ray ◽  
Beta Particle ◽  
Nuclear Excitation ◽  
Ionization Chambers ◽  
Scattering Material ◽  
Pass Through

It is well known that the absorption of neutrons in their passage through matter is due to nuclear collisions, and not appreciably to interaction with extranuclear electrons. A collision of a neutron with a nucleus may result in the scattering of the neutron, or in the disintegration of the nucleus. The experiments of Feather and of Harkins, Gans, and Newson§ have shown that several light elements, C, N, O, F, Ne are disintegrated, the mechanism probably being absorption of the neutron and emission of an alpha particle. Fermi|| has reported that a variety of elements when bombarded by neutrons show the phenomenon of induced radioactivity, emitting beta rays. He suggests that the disintegration process takes place usually by absorption of a neutron and emission of an alpha particle or proton, the resulting nucleus being an unstable radio element, transforming into a stable body by emission of a beta particle. The experiments here to be described show that when neutrons pass through various substances, gamma rays are produced. The origin of this radiation has not definitely been established; nuclear excitation appears to be the most plausible explanation in most cases. 2—Experimental Method The general method consisted in measuring the ionization current produced by a Po + Be source (usually of about 10-15 millicuries) placed above a high pressure ionization chamber, and observing the increased ionization when a block of scattering material was placed immediately above the source. A correction was applied for the diminution of the natural effect caused by the scatterer. The increase in ionization amounted usually to 2-3%, and thus to obtain even a rough measurement of the effect, accurate measurements of the ionization currents were required. For this reason the high pressure ionization chamber was usually used in preference to the counter, since measurements to one part in a thousand are impracticable with the latter. The ionization method has, however, the disadvantage that both gamma rays and neutrons are detected. To distinguish between the two radiations, two similar ionization chambers were used, one containing argon at a pressure of 90 atmospheres, the other hydrogen at about 60 atmospheres. The former is more sensitive to gamma radiation, the latter to neutrons. The ionization chambers were of steel and had cylindrical walls 1 cm thick; the radiations entered through the roofs of the chambers, which were 2·5 cm thick. The inside dimensions were 16 cm high and 12 cm diameter, with a 2-cm diameter central electrode. Collecting potentials of 250-500 volts were used. Measurements were made by a balance method and followed standard practice. From the measurements of ionization currents in argon and hydrogen estimates may be made of the neutron ( n ) and gamma ray (γ) intensities separately. The method by which this is achieved is described in § 11.

ON DIURNAL VARIATION IN COSMIC-RAY INTENSITY AT OTTAWA

1955 ◽  
Vol 33 (10) ◽  
pp. 577-587
Author(s):  
S. D. Chatterjee ◽  
J. N. Bloom
Keyword(s):  
High Pressure ◽  
Statistical Analysis ◽  
Diurnal Variation ◽  
Ionization Chamber ◽  
Cosmic Ray ◽  
Cosmic Ray Intensity ◽  
Rigorous Statistical Analysis ◽  
Local Mean ◽  
Mean Time ◽  
Barometric Coefficient

Cosmic-ray data from a high pressure integrating ionization chamber, obtained at Ottawa, for 129 complete days during September 1950 to July 1951 are subjected to rigorous statistical analysis. The barometric coefficient is −0.19% per mm. of Hg for the period covered by this analysis. The results also indicate a physically significant 24-hr. wave in cosmic-ray intensity, with an amplitude of 0.12% of the total intensity, having its maximum at about 10.40 a.m. local mean time. The existence of the semidiurnal wave, however, is not physically significant.

Study of the energy response of high pressure ionization chamber for high energy gamma-ray

2008 ◽  
Vol 32 (5) ◽  
pp. 370-372 ◽  
Author(s):  
Hua Zheng-Dong ◽  
Xu Xun-Jiang ◽  
Wang Jian-Hua ◽  
Liu Shu-Dong ◽  
Li Jian-Ping
Keyword(s):  
High Pressure ◽  
Ionization Chamber ◽  
Gamma Ray ◽  
High Energy ◽  
Energy Response ◽  
High Energy Gamma ◽  
Energy Gamma

Measurements of Neutron Energy Using a Recoil-Proton Telescope and a High-Pressure Ionization Chamber

1989 ◽  
Vol 118 (1) ◽  
pp. 37 ◽  
Author(s):  
M. Folkard ◽  
G. Makrigiorgos ◽  
M. J. Roper ◽  
A. J. Waker ◽  
B. D. Michael
Keyword(s):  
High Pressure ◽  
Neutron Energy ◽  
Ionization Chamber ◽  
Recoil Proton

High Pressure Ionization Chamber Counters and Their Use

1950 ◽  
Vol 21 (8) ◽  
pp. 699-705 ◽  
Author(s):  
R. Wilson ◽  
L. Beghian ◽  
C. H. Collie ◽  
H. Halban ◽  
G. R. Bishop
Keyword(s):  
High Pressure ◽  
Ionization Chamber

The numerical calculation of the scattering correction in γ ray absorption measurements

1932 ◽  
Vol 28 (4) ◽  
pp. 475-489 ◽  
Author(s):  
G. T. P. Tarrant
Keyword(s):  
High Pressure ◽  
Numerical Calculation ◽  
Ionization Chamber ◽  
Solid Angle ◽  
Wave Length ◽  
Method Of Calculation ◽  
Scattering Correction ◽  
Γ Ray ◽  
Experimental Values ◽  
Absorption Measurements

The method of applying the scattering correction in accurate γ ray absorption measurements is discussed, and it is shown that the scattering correction only diminishes, as the solid angle subtended by the chamber at the source is reduced, if the absorber diameter is reduced correspondingly. The method of calculation of the scattering correction in cases in which the absorber is placed very close to the chamber is explained, and the result of the calculation for one particular chamber is shown to be in satisfactory agreement with the experimental values. The scattering correction allows the ionization function of chambers to be determined and an (ionization function)/(wave-length) curve is shown for a steel thick-walled high-pressure ionization chamber.

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