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performed a series of experiments showing that the gamma ray hypothesis was untenable, and suggested that the new radiation consisted of uncharged particles of approximately the mass of the proton. He performed a series of experiments to verify this, these uncharged particles were eventually called
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are almost exclusively used in AmBe and PuBe neutron sources, respectively. The alpha emitter and the beryllium are pulverized and mixed together in close intimate contact to ensure a high percentage of alpha-emitter and beryllium nuclei in close contact, since the alpha particle has a very short
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Vega-Carillo, Héctor René; Manzanares-Acuña, Eduardo; Becerra-Ferreiro, Ana Maria; Carillo-Nuñez, Aureliano (2002). "Neutron and gamma-ray spectra of PuBe and AmBe".
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range through material, and would lose energy preventing reaction if sufficiently far away. This mixture of material is then packed into a suitable carrier with
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barrier of the beryllium nucleus, the repulsive force due to the positive charge of the nucleus, which contains only four protons, allowing for
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Cox, A.J.; Francois, P.E.; Gatrell, R.P. (1968). "The design of neutron howitzers".
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that emits neutrons in a single direction. It was discovered in the 1930s that
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would release a highly penetrating radiation, at first believed to be
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alpha-emitter is chosen. Historically a variety of isotopes such as
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uranium nuclei. This discovery led to the development of the first
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found that alpha particles striking light elements such as
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114:"neutrons", and Chadwick is credited with this discovery.
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of very high energy. Finally, in 1932 the physicist
93:, who showed that if this unknown radiation fell on
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of the two particles, releasing energetic neutrons.
177:residue, a clear indication that they had instead
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169:nuclei with neutrons in the hopes of making
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121:will suffice, but usually a high
16:Single directional neutron source
173:. To their surprise, they found
101:-containing compound it ejected
153:Neutron howitzers were used by
208:Applied Radiation and Isotopes
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296:"Oregon Administrative Rules"
220:10.1016/S0969-8043(02)00083-0
271:Elements of Nuclear Reactors
255:10.1016/0020-708X(68)90009-4
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321:Neutron-related techniques
185:in 1942, and ultimately
171:transuranic elements
268:Jha, D. K. (2004).
165:in 1938 to bombard
144:radiation shielding
117:Any alpha-emitting
83:Irène Joliot-Curie
123:specific activity
31:that strikes the
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187:nuclear weapons
183:nuclear reactor
159:Fritz Strassman
87:Frédéric Joliot
79:gamma radiation
29:alpha radiation
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214:(2): 167–170.
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107:James Chadwick
59:Herbert Becker
38:would release
25:neutron source
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163:Lise Meitner
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119:radioisotope
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95:paraffin wax
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310:Categories
193:References
189:in 1945.
179:fissioned
155:Otto Hahn
67:beryllium
33:beryllium
228:12150274
148:howitzer
99:hydrogen
53:In 1930
40:neutrons
298:. 2001.
167:uranium
111:England
103:protons
75:lithium
63:Germany
44:Coulomb
36:nucleus
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175:barium
161:, and
139:Pu-239
135:Am-241
131:Ra-226
127:radium
48:fusion
91:Paris
73:, or
71:boron
23:is a
276:ISBN
224:PMID
137:and
85:and
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251:doi
216:doi
109:in
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