{"id":12673,"date":"2016-09-12T14:03:09","date_gmt":"2016-09-12T14:03:09","guid":{"rendered":"http:\/\/sitepourvtc.com\/?page_id=12673"},"modified":"2022-10-18T08:21:47","modified_gmt":"2022-10-18T08:21:47","slug":"compound-nucleus-reactions","status":"publish","type":"page","link":"https:\/\/sitepourvtc.com\/nuclear-power\/reactor-physics\/nuclear-engineering-fundamentals\/neutron-nuclear-reactions\/compound-nucleus-reactions\/","title":{"rendered":"Compound Nucleus Reactions"},"content":{"rendered":"<div   id="8n9s8rpp6h"    class=\"su-quote su-quote-style-default\"><div   id="8n9s8rpp6h"    class=\"su-quote-inner su-u-clearfix su-u-trim\">The compound nucleus is the intermediate state <strong>formed in a <a title=\"Compound Nucleus Reactions\" href=\"http:\/\/sitepourvtc.com\/nuclear-power\/reactor-physics\/nuclear-engineering-fundamentals\/neutron-nuclear-reactions\/compound-nucleus-reactions\/\">compound nucleus reaction<\/a><\/strong>. It is normally one of the excited states of the nucleus formed by the combination of the incident particle and target nucleus. The compound nucleus is excited by both the kinetic energy of the projectile and by the binding nuclear energy.<\/div><\/div>\n<p><strong><span style=\"font-weight: 400;\">To understand the nature of nuclear reactions, the classification according to <strong>the time scale<\/strong> of these reactions has to be introduced. Interaction time is critical for defining the reaction mechanism.<\/span><\/strong><\/p>\n<p><span style=\"font-weight: 400;\">There are <strong>two extreme scenarios<\/strong> for nuclear reactions (not only <a title=\"Neutron Nuclear Reactions\" href=\"http:\/\/sitepourvtc.com\/nuclear-power\/reactor-physics\/nuclear-engineering-fundamentals\/neutron-nuclear-reactions\/\">neutron nuclear reactions<\/a>): <\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">A projectile and a target nucleus are within the range of nuclear forces for <\/span><b>a very short time<\/b><span style=\"font-weight: 400;\"> allowing for an <\/span><b>interaction of a single nucleon only<\/b><span style=\"font-weight: 400;\">. These types of reactions are called <\/span><a title=\"Direct Nuclear Reactions\" href=\"http:\/\/sitepourvtc.com\/nuclear-power\/reactor-physics\/nuclear-engineering-fundamentals\/neutron-nuclear-reactions\/direct-nuclear-reactions\/\"><b>direct nuclear reactions<\/b><\/a><span style=\"font-weight: 400;\">.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">A projectile and a target nucleus are within the range of nuclear forces, allowing for a<\/span><b> large number of interactions between nucleons<\/b><span style=\"font-weight: 400;\">. These types of reactions are called the <\/span><b>c<\/b><b>ompound nucleus reactio<\/b><b>ns<\/b><span style=\"font-weight: 400;\">. <\/span><\/li>\n<\/ul>\n<p><strong><span style=\"font-weight: 400;\"><strong><span style=\"font-weight: 400;\">There is always some <strong>non-direct<\/strong> (multiple internuclear interactions) component in all reactions, but the direct reactions have this component limited.\u00a0<\/span><\/strong><\/span><\/strong><\/p>\n<div   id="8n9s8rpp6h"    class=\"collapsible-container\">\n<h2>What is the Compound Nucleus and the Nuclear Resonance?<\/h2>\n<p>There is no difference between the compound nucleus and the nuclear resonance.<\/p>\n<p>The compound nucleus is the intermediate state <strong>formed in a <a title=\"Compound Nucleus Reactions\" href=\"http:\/\/sitepourvtc.com\/nuclear-power\/reactor-physics\/nuclear-engineering-fundamentals\/neutron-nuclear-reactions\/compound-nucleus-reactions\/\">compound nucleus reaction<\/a><\/strong>. It is normally one of the excited states of the nucleus formed by the combination of the incident particle and target nucleus. Suppose a target nucleus <strong>X<\/strong> is bombarded with particles <strong>a. In that case,<\/strong> it is sometimes observed that the ensuing nuclear reaction occurs with appreciable probability only if the particle\u2019s energy\u00a0is in the neighborhood of certain definite energy values. These energy values are referred to as <strong>resonance energies<\/strong>. The compound nuclei of these certain energies are referred to <strong>as nuclear resonances<\/strong>. Resonances are usually found only at relatively low energies of the projectile. The widths of the resonances increase in general with increasing energies. At higher energies, the widths may reach the order of the distances between resonances, and then no resonances can be observed. The narrowest resonances are usually the compound states of heavy nuclei (such as <a title=\"Fissionable Material\" href=\"http:\/\/sitepourvtc.com\/glossary\/fissionable-material\/\">fissionable\u00a0nuclei<\/a>) and <a title=\"Neutron Energy\" href=\"http:\/\/sitepourvtc.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/fundamental-particles\/neutron\/neutron-energy\/\">thermal\u00a0neutrons<\/a>\u00a0(usually in (n,\u03b3) capture reactions).\u00a0The observation of resonances\u00a0is by no means restricted to <a title=\"Neutron Nuclear Reactions\" href=\"http:\/\/sitepourvtc.com\/nuclear-power\/reactor-physics\/nuclear-engineering-fundamentals\/neutron-nuclear-reactions\/\">neutron nuclear reactions<\/a>.<\/p>\n<p><strong>Danish physicist Niels Bohr introduced the compound nucleus model<\/strong> (the idea of compound nucleus formation) in 1936. This model assumes that the incident particle and the target nucleus become<strong> indistinguishable<\/strong> after the collision and constitute the nucleus\u2019s particular excited state &#8211; the compound nucleus. The projectile has to suffer collisions with constituent nucleons of the target nucleus until it has lost its incident energy to become indistinguishable. Many so these collisions lead to a<strong> complete thermal equilibrium<\/strong> inside the compound nucleus. The compound nucleus is excited by both the kinetic energy of the projectile and by the binding nuclear energy.<\/p>\n<p>This compound system is a <strong>relatively long-lived<\/strong> intermediate state of the particle-target composite system. From the definition, the compound nucleus must live for at least several times longer than is the time of transit of an incident particle across the nucleus (~10<sup>-22<\/sup> s). The time scale of compound nucleus reactions is <strong>10<sup>-18<\/sup> s\u00a0 &#8211; \u00a010<sup>-16<\/sup> s<\/strong>, but lifetimes as long as 10<sup>-14<\/sup> s have also been observed.<\/p>\n<p>A very important feature and a direct consequence of the thermal equilibrium inside a compound nucleus is that the <strong>mode of decay<\/strong> of the compound nucleus <strong>does not depend on how the compound nucleus is formed<\/strong>. Many collisions between nucleons lead to the <strong>loss of information<\/strong> on the entrance channel from the system.\u00a0<strong><span style=\"font-weight: 400;\">The decay mechanism (exit channel) that dominates the decay of C* is determined by the excitation energy in C* and by\u00a0the\u00a0law of probability.<\/span><\/strong><a href=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/09\/Compound-nucleus-reaction.png\"><img loading=\"lazy\" class=\" size-full wp-image-12663 aligncenter\" src=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/09\/Compound-nucleus-reaction.png\" alt=\"compound nucleus reaction\" width=\"652\" height=\"222\" srcset=\"https:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/09\/Compound-nucleus-reaction.png 652w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/09\/Compound-nucleus-reaction-300x102.png 300w\" sizes=\"(max-width: 652px) 100vw, 652px\" \/><\/a><\/p>\n<p style=\"text-align: left;\">These reactions can be considered as two-stage processes.<\/p>\n<ul>\n<li style=\"text-align: left;\">The first stage is the formation of a compound nucleus expressed by <strong>\u03c3<sub>a+X\u279dC*<\/sub><\/strong><\/li>\n<li style=\"text-align: left;\">The second stage is the decay of a compound nucleus expressed by <strong>P<sub>C*\u279db+Y<\/sub><\/strong><\/li>\n<li style=\"text-align: left;\">The result cross-section of certain reaction a+X\u279d[C*]\u279db+Y is given by <strong>\u03c3<sub>(a,b)<\/sub>= \u03c3<sub>a+X\u279dC*<\/sub> . P<sub>C*\u279db+Y<\/sub><\/strong><\/li>\n<\/ul>\n<figure id=\"attachment_12159\" aria-describedby=\"caption-attachment-12159\" style=\"width: 765px\" class=\"wp-caption aligncenter\"><a href=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/06\/uranium_absorption_reaction.png\"><img loading=\"lazy\" class=\"wp-image-12159 size-full\" src=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/06\/uranium_absorption_reaction.png\" alt=\"Uranium absorption reaction\" width=\"775\" height=\"148\" srcset=\"https:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/06\/uranium_absorption_reaction.png 775w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/06\/uranium_absorption_reaction-300x57.png 300w\" sizes=\"(max-width: 775px) 100vw, 775px\" \/><\/a><figcaption id=\"caption-attachment-12159\" class=\"wp-caption-text\">Absorption reaction of fissile 235U. The uncertainty of the exit channel is caused by \u201closs of memory\u201d of resonance [236U].<\/figcaption><\/figure>\n<h2>Resonances<\/h2>\n<p>For the compound nucleus, <strong>peaks in the<a title=\"Neutron cross-section\" href=\"http:\/\/sitepourvtc.com\/neutron-cross-section\/\"> cross-section<\/a><\/strong> are typical. Each peak manifests a particular compound state of the nucleus. These peaks and the associated compound nuclei are usually called <strong>resonances<\/strong>. The behavior of the cross-section between two resonances is usually strongly affected by the effect of nearby resonances.<\/p>\n<figure id=\"attachment_12633\" aria-describedby=\"caption-attachment-12633\" style=\"width: 290px\" class=\"wp-caption alignright\"><a href=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/09\/Compound_nucleus.png\"><img loading=\"lazy\" class=\"size-medium wp-image-12633\" src=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/09\/Compound_nucleus-300x199.png\" alt=\"Compound state - resonance\" width=\"300\" height=\"199\" srcset=\"https:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/09\/Compound_nucleus-300x199.png 300w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/09\/Compound_nucleus.png 719w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-12633\" class=\"wp-caption-text\">Energy levels of the compound state. For neutron absorption reaction on 238U the first resonance E1 corresponds to the excitation energy of 6.67eV. E0 is a base state of 239U.<\/figcaption><\/figure>\n<p><strong>Resonances<\/strong> (particular compound states) are mostly created in <a title=\"Neutron Nuclear Reactions\" href=\"http:\/\/sitepourvtc.com\/nuclear-power\/reactor-physics\/nuclear-engineering-fundamentals\/neutron-nuclear-reactions\/\">neutron nuclear reactions<\/a>, but it is by no means restricted to <a title=\"Neutron Nuclear Reactions\" href=\"http:\/\/sitepourvtc.com\/nuclear-power\/reactor-physics\/nuclear-engineering-fundamentals\/neutron-nuclear-reactions\/\">neutron nuclear reactions<\/a>. The quantum nature of nuclear forces causes the formation of resonances. Each nuclear reaction is a transition between different quantum discrete states or energy levels. The discrete nature of energy transitions plays a key role. Suppose the energy of the projectile (the sum of the Q value and the kinetic energy of the projectile) and the energy of the target nucleus are equal to a compound nucleus at one of the excitation states. In that case, a resonance can be created, and a peak occurs in the cross-section. The allowable state density in this energy region is much lower for the light nucleus, and the \u201cdistance\u201d between states is higher. For heavy nuclei, such as <a title=\"Uranium 238\" href=\"http:\/\/sitepourvtc.com\/nuclear-power-plant\/nuclear-fuel\/uranium\/uranium-238\/\"><sup>238<\/sup>U<\/a>, we can observe a large resonance region in the <a title=\"Neutron Absorption\" href=\"http:\/\/sitepourvtc.com\/nuclear-power\/reactor-physics\/nuclear-engineering-fundamentals\/neutron-nuclear-reactions\/neutron-absorption\/\">neutron absorption<\/a> cross-section.<\/p>\n<figure id=\"attachment_12819\" aria-describedby=\"caption-attachment-12819\" style=\"width: 290px\" class=\"wp-caption alignright\"><a href=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/10\/ground-state-compound-nucleus.png\"><img loading=\"lazy\" class=\"size-medium wp-image-12819\" src=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/10\/ground-state-compound-nucleus-300x163.png\" alt=\"ground state compound nucleus - excitation\" width=\"300\" height=\"163\" srcset=\"https:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/10\/ground-state-compound-nucleus-300x163.png 300w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/10\/ground-state-compound-nucleus.png 736w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-12819\" class=\"wp-caption-text\">The position of the energy levels during the formation of a compound nucleus. Ground state and energy states.<\/figcaption><\/figure>\n<p>The compound states (resonances) are observed at low excitation energies. This is due to the fact, the energy gap between the states is large. At high excitation energy, the gap between two compound states is very small, and the widths of resonances may reach the order of the distances between resonances. Therefore, no resonances can be observed at high energies, and the cross-section in this energy region is continuous and smooth.<\/p>\n<p style=\"text-align: center;\"><a href=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/09\/Resonance-region-cross-section.png\"><img loading=\"lazy\" class=\"size-medium wp-image-12667 aligncenter\" src=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/09\/Resonance-region-cross-section-300x221.png\" alt=\"Resonance region - Compound Nucleus\" width=\"300\" height=\"221\" srcset=\"https:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/09\/Resonance-region-cross-section-300x221.png 300w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/09\/Resonance-region-cross-section-220x161.png 220w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2015\/09\/Resonance-region-cross-section.png 737w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a>Region of resonances of <a title=\"Uranium 238\" href=\"http:\/\/sitepourvtc.com\/nuclear-power-plant\/nuclear-fuel\/uranium\/uranium-238\/\"><sup>238<\/sup>U<\/a> nuclei. Source: JANIS (Java-based Nuclear Data Information Software);\u00a0The ENDF\/B-VII.1 Nuclear Data Library<\/p>\n<h2>Direct Reactions vs. Compound Nucleus Reactions<\/h2>\n<h3>Direct Reactions<\/h3>\n<ul>\n<li>The direct reactions are fast and involve a <strong>single-nucleon interaction<\/strong>.<\/li>\n<li>The interaction time must be very short<strong> (~10<sup>-22<\/sup> s)<\/strong>.<\/li>\n<li>The direct reactions require incident particle energy <strong>larger than \u223c 5 MeV\/Ap<\/strong>. (Ap is the atomic mass number of a projectile)<\/li>\n<li>Incident particles interact <strong>on the surface<\/strong> of a target nucleus rather than in the volume of a target nucleus.<\/li>\n<li>Products of the direct reactions <strong>are not distributed isotropically in angle<\/strong>, but they are forward-focused.<\/li>\n<li>Direct reactions are of importance in measurements of nuclear structure.<\/li>\n<\/ul>\n<h3>Compound Nucleus Reactions<\/h3>\n<ul>\n<li>The compound nucleus is a <strong>relatively long-lived<\/strong> intermediate state of the particle-target composite system.<\/li>\n<li>The compound nucleus reactions involve <strong>many nucleon-nucleon interactions<\/strong>.<\/li>\n<li>A large number of collisions between the nucleons leads to a <strong>thermal equilibrium<\/strong> inside the compound nucleus.<\/li>\n<li>The time scale of compound nucleus reactions is <strong>10<sup>-18<\/sup> s &#8211; 10<sup>-16<\/sup> s<\/strong>.<\/li>\n<li>The compound nucleus reactions are usually created if the projectile has <strong>low energy<\/strong>.<\/li>\n<li>Incident particles interact in the volume of a target nucleus.<\/li>\n<li>Products of the compound nucleus reactions are distributed <strong>near isotropically in angle<\/strong> (the nucleus loses memory of how it was created &#8211; <em><strong>Bohr\u2019s hypothesis of independence<\/strong><\/em>).<\/li>\n<li><strong>The decay mode<\/strong>\u00a0of the compound nucleus <strong>does not depend on how the compound nucleus is formed<\/strong>.<\/li>\n<li>Resonances in the cross-section are typical for the compound nucleus reaction.<\/li>\n<\/ul>\n<\/div>\n<div   id="8n9s8rpp6h"     class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights \"><div   id="8n9s8rpp6h"     class=\"inside-grid-column\">\u00a0 <div   id="8n9s8rpp6h"    class=\"su-accordion su-u-trim\"><div   id="8n9s8rpp6h"    class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-plus su-spoiler-closed\" data-scroll-offset=\"0\"><div   id="8n9s8rpp6h"    class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\"><span class=\"su-spoiler-icon\"><\/span>References:<\/div><div   id="8n9s8rpp6h"    class=\"su-spoiler-content su-u-clearfix su-u-trim\"><strong>Nuclear and Reactor Physics:<\/strong>\n<ol>\n<li>J. R. Lamarsh, Introduction to Nuclear Reactor Theory, 2nd ed., Addison-Wesley, Reading,\u00a0MA (1983).<\/li>\n<li>J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.<\/li>\n<li>W. M. Stacey, Nuclear Reactor Physics, John Wiley &amp; Sons, 2001, ISBN: 0- 471-39127-1.<\/li>\n<li>Glasstone, Sesonske. Nuclear Reactor Engineering: Reactor Systems Engineering,\u00a0Springer; 4th edition, 1994, ISBN:\u00a0978-0412985317<\/li>\n<li>W.S.C. Williams. Nuclear and Particle Physics.\u00a0Clarendon Press; 1 edition, 1991, ISBN:\u00a0978-0198520467<\/li>\n<li>G.R.Keepin. Physics of Nuclear Kinetics.\u00a0Addison-Wesley Pub. Co; 1st edition, 1965<\/li>\n<\/ol>\n<p><strong><\/strong><strong>Advanced Reactor Physics:<\/strong><\/p>\n<ol>\n<li>K. O. Ott, W. A. Bezella, Introductory Nuclear Reactor Statics, American Nuclear Society, Revised edition (1989), 1989, ISBN: 0-894-48033-2.<\/li>\n<li>K. O. Ott, R. J. Neuhold, Introductory Nuclear Reactor Dynamics, American Nuclear Society, 1985, ISBN: 0-894-48029-4.<\/li>\n<li><span style=\"font-weight: 400;\">D. L. Hetrick, Dynamics of Nuclear Reactors, American Nuclear Society, 1993, ISBN: 0-894-48453-2.\u00a0<\/span><\/li>\n<li>E. E. Lewis, W. F. Miller, Computational Methods of Neutron Transport, American Nuclear Society, 1993, ISBN: 0-894-48452-4.<\/li>\n<\/ol>\n<\/div><\/div><\/div><div   id="8n9s8rpp6h"    class=\"su-divider su-divider-style-dotted\" style=\"margin:15px 0;border-width:2px;border-color:#999999\"><\/div> <\/div><\/div><div   id="8n9s8rpp6h"    class=\"su-divider su-divider-style-default\" style=\"margin:15px 0;border-width:2px;border-color:#999999\"><\/div><div   id="8n9s8rpp6h"     class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights \"><div   id="8n9s8rpp6h"     class=\"inside-grid-column\">\n<h2>See previous:<\/h2>\n<a href=\"\" class=\"su-button su-button-style-flat\" style=\"color:#606060;background-color:#ffffff;border-color:#cccccc;border-radius:10px;-moz-border-radius:10px;-webkit-border-radius:10px\" target=\"_self\"><span style=\"color:#606060;padding:7px 20px;font-size:16px;line-height:24px;border-color:#ffffff;border-radius:10px;-moz-border-radius:10px;-webkit-border-radius:10px;text-shadow:0px 0px 0px #000000;-moz-text-shadow:0px 0px 0px #000000;-webkit-text-shadow:0px 0px 0px #000000\"><i class=\"sui sui-link\" style=\"font-size:16px;color:#5d5d5d\"><\/i> <\/span><\/a><\/div><\/div><div   id="8n9s8rpp6h"     class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights \"><div   id="8n9s8rpp6h"     class=\"inside-grid-column\">\n<h2>See above:<\/h2>\n<p>Neutron Nuclear Reactions<a href=\"http:\/\/sitepourvtc.com\/nuclear-power\/reactor-physics\/nuclear-engineering-fundamentals\/neutron-nuclear-reactions\/\" class=\"su-button su-button-style-flat\" style=\"color:#606060;background-color:#ffffff;border-color:#cccccc;border-radius:10px;-moz-border-radius:10px;-webkit-border-radius:10px\" target=\"_self\"><span style=\"color:#606060;padding:7px 20px;font-size:16px;line-height:24px;border-color:#ffffff;border-radius:10px;-moz-border-radius:10px;-webkit-border-radius:10px;text-shadow:0px 0px 0px #000000;-moz-text-shadow:0px 0px 0px #000000;-webkit-text-shadow:0px 0px 0px #000000\"><i class=\"sui sui-link\" style=\"font-size:16px;color:#5d5d5d\"><\/i> <\/span><\/a><\/p><\/div><\/div><div   id="8n9s8rpp6h"     class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights \"><div   id="8n9s8rpp6h"     class=\"inside-grid-column\">\n<h2>See next:<\/h2>\n<a href=\"\" class=\"su-button su-button-style-flat\" style=\"color:#606060;background-color:#ffffff;border-color:#cccccc;border-radius:10px;-moz-border-radius:10px;-webkit-border-radius:10px\" target=\"_self\"><span style=\"color:#606060;padding:7px 20px;font-size:16px;line-height:24px;border-color:#ffffff;border-radius:10px;-moz-border-radius:10px;-webkit-border-radius:10px;text-shadow:0px 0px 0px #000000;-moz-text-shadow:0px 0px 0px #000000;-webkit-text-shadow:0px 0px 0px #000000\"><i class=\"sui sui-link\" style=\"font-size:16px;color:#5d5d5d\"><\/i> <\/span><\/a><\/div><\/div>\n","protected":false},"excerpt":{"rendered":"<p>To understand the nature of nuclear reactions, the classification according to the time scale of these reactions has to be introduced. Interaction time is critical for defining the reaction mechanism. There are two extreme scenarios for nuclear reactions (not only neutron nuclear reactions): A projectile and a target nucleus are within the range of nuclear &#8230; <a title=\"Compound Nucleus Reactions\" class=\"read-more\" href=\"https:\/\/sitepourvtc.com\/nuclear-power\/reactor-physics\/nuclear-engineering-fundamentals\/neutron-nuclear-reactions\/compound-nucleus-reactions\/\" aria-label=\"More on Compound Nucleus Reactions\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":12656,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"generate_page_header":""},"_links":{"self":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/12673"}],"collection":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/comments?post=12673"}],"version-history":[{"count":6,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/12673\/revisions"}],"predecessor-version":[{"id":32665,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/12673\/revisions\/32665"}],"up":[{"embeddable":true,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/12656"}],"wp:attachment":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/media?parent=12673"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}