Emission of Long-Range Alpha Particles in the Fission ofU238with 17.5-MeV Protons

1965 ◽  
Vol 139 (2B) ◽  
pp. B307-B314 ◽  
Author(s):  
R. A. Atneosen ◽  
T. D. Thomas ◽  
G. T. Garvey
Keyword(s):  
Long Range ◽  
Alpha Particles ◽  
Mev Protons

XVIII.—The Emission of Long-Range Alpha Particles in Fission

1963 ◽  
Vol 66 (3) ◽  
pp. 192-209
Author(s):  
N. Feather
Keyword(s):  
Long Range ◽  
Alpha Particle ◽  
Experimental Tests ◽  
Alpha Particles ◽  
Ternary Fission ◽  
Neutron Excess ◽  
Final Energy ◽  
Open Question

It is generally agreed that the long-range alpha particles of fission are set free before the fragment nuclei have acquired more than a small fraction of their final energy of separation, but whether the alpha particle is liberated before the instant of scission, at that instant, or from one of the fragment nuclei very shortly thereafter, has remained an open question. Each of these views has been seriously advocated. These various hypotheses are examined in relation to recently published information regarding the distribution of mass in low-eneigy ternary fission, and other considerations, and it is suggested that the hypothesis having the strongest claim to attention is that which assumes that the alpha particles originate in the heavy fragments exclusively, being liberated, very shortly after the instant of scission, with probability not much less than unity, from fragment nuclei of low yield and small neutron excess. Conclusions which would follow, if this hypothesis were accepted, are indicated, and possible experimental tests of these conclusions are suggested.

Alpha-particles from several elements bombarded with 30, 43 and 56 MeV protons

1963 ◽  
Vol 47 ◽  
pp. 19-32 ◽  
Author(s):  
Jiro Muto ◽  
Hidehiko Itoh ◽  
Kotoyuki Okano ◽  
Naoko Shiomi ◽  
Kyue Fukuda ◽  
...  
Keyword(s):  
Alpha Particles ◽  
Mev Protons

Electric Field Induced De-channeling in LiNbO3

1993 ◽  
Vol 316 ◽  
Author(s):  
R. L. Zimmerman ◽  
D. Ila ◽  
N. Kukhtarev ◽  
E. K. Williams
Keyword(s):  
Electric Field ◽  
Single Crystals ◽  
Ion Beam ◽  
Crystal Defects ◽  
Alpha Particles ◽  
Fringe Field ◽  
Beam Direction ◽  
Ion Channeling ◽  
Piezoelectric Strain ◽  
Mev Protons

ABSTRACTAn electric field has been imposed on single crystals of pure and doped LiNbO3 during bombardment with 1.03 MeV protons and 2.1 MeV alpha particles. Simultaneous (p,p), (p,α) and (p,p'γ) channeling between the crystal planes showed that the channeling is less pronounced when an electric field of 106 volts/m is imposed perpendicular to the incident ion beam direction and to the channeling planes in the crystal. The results obtained are discussed and compared to the effects due to the fringe field outside the crystal, differential cation-anion movement, movement of interplanar impurities, the piezoelectric strain and movement or creation of crystal defects on ion channeling.

The angular distributions of the long-range alpha-particles from the reaction F19(p, α0)O16

1958 ◽  
Vol 7 ◽  
pp. 116-125 ◽  
Author(s):  
Akira Isoya ◽  
Haruko Ohmura ◽  
Teruo Momota
Keyword(s):  
Long Range ◽  
Alpha Particles ◽  
Angular Distributions

Rapid Migration of Defects in Ion-Implanted Silicon

1997 ◽  
Vol 469 ◽  
Author(s):  
J. Lalita ◽  
P. Pellegrino ◽  
A. Hallén ◽  
B. G. Svensson ◽  
N. Keskitalo ◽  
...  
Keyword(s):  
Activation Energy ◽  
Temperature Dependence ◽  
Dose Rate ◽  
Long Range ◽  
Room Temperature ◽  
Rate Effect ◽  
High Dose ◽  
Range Migration ◽  
Mev Protons ◽  
Dose Rate Effect

ABSTRACTThe temperature dependence of the so-called reverse dose rate effect for generation of vacancy-type defects in silicon has been investigated using samples implanted with 1.3 MeV protons at temperatures between 70 and 300 K. The effect is found to involve a thermally controlled process which exhibits an activation energy of ∼0.065 eV, possibly associated with rapid migration of Si self-interstitials (I). Further, using a concept of dual Si ion-implants long range migration of I:s at room temperature has been studied. Annihilation of vacancy-type defects at a depth of ∼3 μm is obtained by injection of I:s from a shallow implant with sufficiently high dose.

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