Nuclear Reactions

Abstract

Nuclear reactions generate energy in nuclear reactors, in stars, and are responsible for the existence of all elements heavier than hydrogen in the Universe. Nuclear reactions denote reactions between nuclei, and between nuclei and other fundamental particles, such as electrons and photons. A short description of the conservation laws and the definition of basic physical quantities is presented, followed by a more detailed account of specific cases: (i) formation and decay of compound nuclei; (ii)direct reactions; (iii) photon and electron scattering; (iv) heavy ion collisions; (v) formation of a quark–gluon plasma; (vi) thermonuclear reactions; and (vii) reactions with radioactive beams. Whenever necessary, basic equations are introduced to help understand general properties of these reactions.

A Monte Carlo study on the secondary neutron generation by oxygen ion beams for radiotherapy and its comparison to lighter ions

“…These figures show that most of the neutrons in the FR region are emitted in the downstream direction, which contrasts with the neutrons in the TE region, mainly emitted isotropically. The reason behind this is the way in which the neutrons in the FR and TE regions are produced, given that TE neutrons originate in the de-excitation of nuclei, the mechanism of a nucleus decaying does not depend on the specific pathway it took to reach this excited state (Bertulani 2003). On the other hand, the neutrons in the FR region stem mainly from the prompt neutron emission, with most of them emitted at a solid angle between 0 and π, more precisely 80.9(25)%, 88.3(16)% and 92.2(9)% of the total FR fluence for the primary oxygen beam of 332.52 MeV u −1 for FLUKA, TOPAS and MCNP, respectively.…”

Current Status of Nuclear Physics Research

“…Research in nuclear reactions accompanied closely the development of models of nuclear structure [135]. Two aspects of nuclear structure were in apparent conflict.…”

“…Reactions with unstable nuclei use a stable target (e.g., a proton gas target) and by inference one can access information on cross sections of astrophysical interest. This information relies heavily on reaction theory [135]. We cite a few phenomena (only a few, indeed) of current interest using these techniques.…”

Analysis of the $^{16}$O$(d,p)^{17}$O and $^{16}$O$(d,n)^{17}$F transfer reactions to determine astrophysical direct capture cross sections

“…0.96 (14) 0.66 (14) 0.95(10) 0.93(11) S (Set II) 1.00(7) 0.62 (14) 0.91(10) 0.92(15) ANC (Set I) ( f m −1 ) 0.99-0.74 4911-3192 0.79-0.64 9-7 ANC (Set II) ( f m −1 ) 0.96-0.84 4666-2947 0.76-0.61 9-7…”

“…The astrophysical S-factors for the 16 O(p,γ) 17 F and 16 O(n,γ) 17 O capture cross sections were determined using the Radcap code [14]. The results are shown in Figure 3 (a) and (b) compared to the experimental data of Morlock et al [15], and Igashira et al [9], respectively.…”