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Branching Rate
In particle physics and nuclear physics, the branching fraction (or branching ratio) for a decay is the fraction of particles which decay by an individual decay mode or with respect to the total number of particles which decay. It applies to either the radioactive decay of atoms or the decay of elementary particles. It is equal to the ratio of the partial decay constant of the decay mode to the overall decay constant. Sometimes a partial half-life is given, but this term is misleading; due to competing modes, it is not true that half of the particles will decay through a particular decay mode after its partial half-life. The partial half-life is merely an alternate way to specify the partial decay constant , the two being related through: :t_ = \frac. For example, for decays of Cs, 98.13% are ε (electron capture) or β (positron) decays, and 1.87% are β (electron) decays. The half-life of this isotope is 6.480 days, which corresponds to a total decay constant of 0.1070&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle Physics
Particle physics or high-energy physics is the study of Elementary particle, fundamental particles and fundamental interaction, forces that constitute matter and radiation. The field also studies combinations of elementary particles up to the scale of protons and neutrons, while the study of combinations of protons and neutrons is called nuclear physics. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) and bosons (force-carrying particles). There are three Generation (particle physics), generations of fermions, although ordinary matter is made only from the first fermion generation. The first generation consists of Up quark, up and down quarks which form protons and neutrons, and electrons and electron neutrinos. The three fundamental interactions known to be mediated by bosons are electromagnetism, the weak interaction, and the strong interaction. Quark, Quarks cannot exist on their own but form hadrons. Hadrons that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arsenic-74
Arsenic (33As) has 32 known isotopes and at least 10 isomers. Only one of these isotopes, 75As, is stable; as such, it is considered a monoisotopic element. The longest-lived radioisotope is 73As with a half-life of 80 days. List of isotopes , -id=Arsenic-64 , rowspan=2 , 64As , rowspan=2 style="text-align:right" , 33 , rowspan=2 style="text-align:right" , 31 , rowspan=2 , 63.95756(22)# , rowspan=2 , 69.0(14) ms , β+ , 64Ge , rowspan=2 , 0+# , rowspan=2 , , - , β+, p? , 63Ga , -id=Arsenic-65 , rowspan=2 , 65As , rowspan=2 style="text-align:right" , 33 , rowspan=2 style="text-align:right" , 32 , rowspan=2 , 64.949611(91) , rowspan=2 , 130.3(6) ms , β+ , 65Ge , rowspan=2 , 3/2−# , rowspan=2 , , - , β+, p? , 64Ga , -id=Arsenic-66 , 66As , style="text-align:right" , 33 , style="text-align:right" , 33 , 65.9441488(61) , 95.77(23) ms , β+ , 66Ge , 0+ , , -id=Arsenic-66m1 , style="text-indent:1em" , 66m1As , colspan= ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Physics
Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions, in addition to the study of other forms of nuclear matter. Nuclear physics should not be confused with atomic physics, which studies the atom as a whole, including its electrons. Discoveries in nuclear physics have led to applications in many fields such as nuclear power, nuclear weapons, nuclear medicine and magnetic resonance imaging, industrial and agricultural isotopes, ion implantation in materials engineering, and radiocarbon dating in geology and archaeology. Such applications are studied in the field of nuclear engineering. Particle physics evolved out of nuclear physics and the two fields are typically taught in close association. Nuclear astrophysics, the application of nuclear physics to astrophysics, is crucial in explaining the inner workings of stars and the origin of the chemical elements. History The history of nuclear physics as a discipline ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle Physics
Particle physics or high-energy physics is the study of Elementary particle, fundamental particles and fundamental interaction, forces that constitute matter and radiation. The field also studies combinations of elementary particles up to the scale of protons and neutrons, while the study of combinations of protons and neutrons is called nuclear physics. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) and bosons (force-carrying particles). There are three Generation (particle physics), generations of fermions, although ordinary matter is made only from the first fermion generation. The first generation consists of Up quark, up and down quarks which form protons and neutrons, and electrons and electron neutrinos. The three fundamental interactions known to be mediated by bosons are electromagnetism, the weak interaction, and the strong interaction. Quark, Quarks cannot exist on their own but form hadrons. Hadrons that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic, Molecular, And Optical Physics
Atomic, molecular, and optical physics (AMO) is the study of matter–matter and light–matter interactions, at the scale of one or a few atoms and energy scales around several electron volts. The three areas are closely interrelated. AMO theory includes classical, semi-classical and quantum treatments. Typically, the theory and applications of emission, absorption, scattering of electromagnetic radiation (light) from Excited state, excited atoms and molecules, analysis of spectroscopy, generation of lasers and masers, and the optical properties of matter in general, fall into these categories. Atomic and molecular physics Atomic physics is the subfield of AMO that studies atoms as an isolated system of electrons and an atomic nuclei, atomic nucleus, while molecular physics is the study of the physical properties of molecules. The term ''atomic physics'' is often associated with nuclear power and nuclear bombs, due to the synonymous use of ''atomic'' and ''nuclear'' i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branching Fraction
In particle physics and nuclear physics, the branching fraction (or branching ratio) for a decay is the fraction of particles which decay by an individual decay mode or with respect to the total number of particles which decay. It applies to either the radioactive decay of atoms or Particle decay, the decay of elementary particles. It is equal to the ratio of the partial decay constant of the decay mode to the overall decay constant. Sometimes a partial half-life is given, but this term is misleading; due to competing modes, it is not true that half of the particles will decay through a particular decay mode after its partial half-life. The partial half-life is merely an alternate way to specify the partial decay constant , the two being related through: :t_ = \frac. For example, for decays of Caesium, Cs, 98.13% are ε (electron capture) or β (Positron emission, positron) decays, and 1.87% are β (Electron emission, electron) decays. The half-life of this isotope is 6.480 d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holmium-164
Natural holmium (67Ho) contains one observationally stable isotope, 165Ho. The below table lists 39 isotopes spanning 140Ho through 178Ho as well as 40 nuclear isomers. Among the known synthetic radioactive isotopes; the most stable one is 163Ho, with a half-life of 4,570 years. All other radioisotopes have half-lives not greater than 1.117 days in their ground states (although the metastable 166m1Ho has a half-life of about 1,200 years), and most have half-lives under 3 hours. List of isotopes , -id=Holmium-140 , 140Ho , style="text-align:right" , 67 , style="text-align:right" , 73 , 139.96853(54)# , 6(3) ms , p , 139Dy , 8+# , , -id=Holmium-141 , 141Ho , style="text-align:right" , 67 , style="text-align:right" , 74 , 140.96311(43)# , 4.1(1) ms , p , 140Dy , (7/2−) , , -id=Holmium-141m , style="text-indent:1em" , 141mHo , colspan="3" style="text-indent:2em" , 66(2) keV , 7.3(3) μs , p , 140Dy , (1/2+) , , -id=Holmium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iodine-126
There are 40 known isotopes of iodine (53I) from 108I to 147I; all undergo radioactive decay except 127I, which is stable. Iodine is thus a monoisotopic element. Its longest-lived radioactive isotope, 129I, has a half-life of 16.14 million years, which is too short for it to exist as a primordial nuclide. Cosmogenic sources of 129I produce very tiny quantities of it that are too small to affect atomic weight measurements; iodine is thus also a mononuclidic element—one that is found in nature only as a single nuclide. Most 129I derived radioactivity on Earth is man-made, an unwanted long-lived byproduct of early nuclear tests and nuclear fission accidents. All other iodine radioisotopes have half-lives less than 60 days, and four of these are used as tracers and therapeutic agents in medicine - 123I, 124I, 125I, and 131I. All industrial use of radioactive iodine isotopes involves these four. The isotope 135I has a half-life less than seven hours, which is inconveniently short ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indium-112
Indium (49In) consists of two primordial nuclides, with the most common (~ 95.7%) nuclide (115In) being measurably though weakly radioactive. Its spin-forbidden decay has a half-life of 4.41×1014 years, much longer than the currently accepted age of the Universe. The stable isotope 113In is only 4.3% of naturally occurring indium. Among elements with a known stable isotope, only tellurium and rhenium similarly occur with a stable isotope in lower abundance than the long-lived radioactive isotope. Other than 115In, the longest-lived radioisotope is 111In, with a half-life of 2.8047 days. All other radioisotopes have half-lives less than a day. This element also has 47 isomers, the longest-lived being 114m1In, with a half-life of 49.51 days. All other meta-states have half-lives less than a day, most less than an hour, and many measured in milliseconds or less. Indium-111 is used medically in nuclear imaging, as a radiotracer nuclide tag for gamma camera localization of protein ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhodium-102
Naturally occurring rhodium (45Rh) is composed of only one stable isotope, 103Rh. The most stable radioisotopes are 101Rh with a half-life of 3.3 years, 102Rh with a half-life of 207 days, and 99Rh with a half-life of 16.1 days. Thirty other radioisotopes have been characterized with atomic weights ranging from 88.949 u (89Rh) to 121.943 u (122Rh). Most of these have half-lives that are less than an hour except 100Rh (half-life: 20.8 hours) and 105Rh (half-life: 35.36 hours). There are also numerous meta states with the most stable being 102mRh (0.141 MeV) with a half-life of about 3.7 years and 101mRh (0.157 MeV) with a half-life of 4.34 days. The primary decay mode before the only stable isotope, 103Rh, is electron capture and the primary mode after is beta emission. The primary decay product before 103Rh is ruthenium and the primary product after is palladium. List of isotopes , -id=Rhodium-90 , rowspan=2, 90Rh , rowspan=2 style="text-align:right" , 45 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper-64
Copper-64 (Cu) is a positron and beta emitting isotope of copper, with applications for molecular radiotherapy and positron emission tomography. Its unusually long half-life (12.7-hours) for a positron-emitting isotope makes it increasingly useful when attached to various ligands, for PET and PET-CT scanning. Properties Cu has a half-life of 12.7 hours and decays 17.9% by positron emission to Ni, 39.0% by beta decay to Zn, 43.1% by electron capture to Ni, and 0.475% gamma radiation/internal conversion. These emissions are 0.579 MeV, 0.653 MeV and 1.35 MeV for beta minus, positron, and gamma respectively. Production Copper-64 can be produced by several different reactions with the most common methods using either a reactor or a particle accelerator. Thermal neutrons can produce Cu in low specific activity (the number of decays per second per amount of substance) and low yield through the Cu(n,γ)Cu reaction. At the University of Missouri Research Reactor Center (MURR) Cu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
