大爆炸---宇宙的起源
... body thermal energy coming from all parts of the sky. The radiation is isotropic to roughly one part in 100,000. As the universe expanded, adiabatic cooling caused the plasma to lose energy until it became favorable for electrons to combine with protons, forming hydrogen atoms. This recombination ev ...
... body thermal energy coming from all parts of the sky. The radiation is isotropic to roughly one part in 100,000. As the universe expanded, adiabatic cooling caused the plasma to lose energy until it became favorable for electrons to combine with protons, forming hydrogen atoms. This recombination ev ...
Review & Closure - Little Shop of Physics
... Many speculative plans for spaceships capable of inters travel have been developed over the years. Nearly all are ered by the fusion of light nuclei, one of a very few p sources capable of providing the incredibly large ene required. A typical design for a fusion-powered craft h 1.7 * 106 kg ship br ...
... Many speculative plans for spaceships capable of inters travel have been developed over the years. Nearly all are ered by the fusion of light nuclei, one of a very few p sources capable of providing the incredibly large ene required. A typical design for a fusion-powered craft h 1.7 * 106 kg ship br ...
7.3 – Nuclear Reactions, Fission and Fusion 7.3.1 – Describe and
... 7.3 – Nuclear Reactions, Fission and Fusion 7.3.1 – Describe and give an example of an artificial transmutation 7.3.3 – Define the term unified atomic mass unit Students must be familiar with the units MeV c -2 and GeV c -2 for mass 7.3.4 - Apply the Einstein mass – energy equivalence relationship 7 ...
... 7.3 – Nuclear Reactions, Fission and Fusion 7.3.1 – Describe and give an example of an artificial transmutation 7.3.3 – Define the term unified atomic mass unit Students must be familiar with the units MeV c -2 and GeV c -2 for mass 7.3.4 - Apply the Einstein mass – energy equivalence relationship 7 ...
Nuclear Structure`07: Exciting, Broad, Relevant
... To arrive at a comprehensive and unified microscopic description of all nuclei and low-energy reactions from the the basic interactions between the constituent protons and neutrons – Self-bound, two-component quantum many-fermion system – Complicated interaction based on QCD with at least two- and t ...
... To arrive at a comprehensive and unified microscopic description of all nuclei and low-energy reactions from the the basic interactions between the constituent protons and neutrons – Self-bound, two-component quantum many-fermion system – Complicated interaction based on QCD with at least two- and t ...
Big Bang Theory - Clark Planetarium
... zero) • Photons that make up the cosmic background radiation are now microwaves – most of these photons were produced by the particle antiparticle annihilation at about one tenthousandth of a second ...
... zero) • Photons that make up the cosmic background radiation are now microwaves – most of these photons were produced by the particle antiparticle annihilation at about one tenthousandth of a second ...
nuclear astrophysics applications for accelerators
... Figure 8: 44Ti is produced in the vicinity of the mass cut. If the mass cut occurs at a smaller radius, much more 44Ti is ejected (and vice versa) [Timmes 1996]. A particularly important aspect of core collapse supernovae is that they are widely viewed as the most likely site of the r-process, thoug ...
... Figure 8: 44Ti is produced in the vicinity of the mass cut. If the mass cut occurs at a smaller radius, much more 44Ti is ejected (and vice versa) [Timmes 1996]. A particularly important aspect of core collapse supernovae is that they are widely viewed as the most likely site of the r-process, thoug ...
Additional Problems - AppServ Open Project 2.4.9
... found to be 3.3 × 107 m/s. Because the velocity of the neutrons could not be determined directly, a second experiment was performed using neutrons from the same source and nitrogen nuclei as the target. The maximum recoil speed of the nitrogen nuclei was found to be 4.7 × 106 m/s. The masses of a pr ...
... found to be 3.3 × 107 m/s. Because the velocity of the neutrons could not be determined directly, a second experiment was performed using neutrons from the same source and nitrogen nuclei as the target. The maximum recoil speed of the nitrogen nuclei was found to be 4.7 × 106 m/s. The masses of a pr ...
Atomic Structure
... – Surrounded by electron cloud •1st 20 elements of periodic table— neutrons to protons is 1:1 •Larger nuclei require more neutrons than protons to increase binding energy and maintain nuclear stability •Nuclei not having an appropriate neutron to proton ratio are unstable From “Atomic Nucleus.” Wiki ...
... – Surrounded by electron cloud •1st 20 elements of periodic table— neutrons to protons is 1:1 •Larger nuclei require more neutrons than protons to increase binding energy and maintain nuclear stability •Nuclei not having an appropriate neutron to proton ratio are unstable From “Atomic Nucleus.” Wiki ...
FUSION AND FISSION
... of a few neutrons, or are VERY different protons & neutrons. elements than the reactant. • The product is an alpha, • Nuclear reactions must be beta, or gamma particle started, so there are 2 and ONE new atom. things on the left hand side. There is only ONE thing – Nuclear fission: makes 2 on the le ...
... of a few neutrons, or are VERY different protons & neutrons. elements than the reactant. • The product is an alpha, • Nuclear reactions must be beta, or gamma particle started, so there are 2 and ONE new atom. things on the left hand side. There is only ONE thing – Nuclear fission: makes 2 on the le ...
Notes: Stellar Nucleosynthesis
... Fusion of Heavier Elements • Iron is a “star killer” • fusion of iron takes energy (endothermic) instead of giving off energy (exothermic) • therefore, stars begin to “die” once iron is created. ...
... Fusion of Heavier Elements • Iron is a “star killer” • fusion of iron takes energy (endothermic) instead of giving off energy (exothermic) • therefore, stars begin to “die” once iron is created. ...
Gravitational waves and neutrino emission from the merger of
... Today’s topic = Coalescence of binary neutron stars ✓Promising source of GWs ✓Theoretical candidate of Short-Gamma-Ray Burst ✓High-end laboratory for Nuclear theory A nuclear theory ⇒ Mass-Radius relation for Neutron Star Image of GRB ...
... Today’s topic = Coalescence of binary neutron stars ✓Promising source of GWs ✓Theoretical candidate of Short-Gamma-Ray Burst ✓High-end laboratory for Nuclear theory A nuclear theory ⇒ Mass-Radius relation for Neutron Star Image of GRB ...
7.2 - Moodle
... (-) charge, and so are deflected in the opposite direction. • the gamma rays have no charge; thus, are not deflected by the field. • Be a Thinker! • Why are the beta particles deflected more than the alpha ones? ...
... (-) charge, and so are deflected in the opposite direction. • the gamma rays have no charge; thus, are not deflected by the field. • Be a Thinker! • Why are the beta particles deflected more than the alpha ones? ...
Exit Slip: Atomic Structure and Nuclear Chemistry-1
... can be seen that the combined value of mass plus energy is conserved in these reactions. Which of these is the BEST example of such a reaction (11.b)? A. conversion of prehistoric plants to fossil fuels B. sudden explosive reactions with gaseous products C. splitting of a uranium nucleus into barium ...
... can be seen that the combined value of mass plus energy is conserved in these reactions. Which of these is the BEST example of such a reaction (11.b)? A. conversion of prehistoric plants to fossil fuels B. sudden explosive reactions with gaseous products C. splitting of a uranium nucleus into barium ...
Problem Set 4
... (i) Assume that the binding energy is equivalent to the electrical potential energy for an atom. If the nitrogen gas molecule (N2) has a separation distance of 0.11 nm between the nucleus and an outer electron, what is the binding energy of this electron? Draw a picture of this system. (ii) Now expl ...
... (i) Assume that the binding energy is equivalent to the electrical potential energy for an atom. If the nitrogen gas molecule (N2) has a separation distance of 0.11 nm between the nucleus and an outer electron, what is the binding energy of this electron? Draw a picture of this system. (ii) Now expl ...
Origin of Elements - Madison Public Schools
... – almost exactly what is observed in the visible universe. ...
... – almost exactly what is observed in the visible universe. ...
Nuclear drip line
In nuclear physics, the boundaries for nuclear particle-stability are called drip lines. Atomic nuclei contain both protons and neutrons—the number of protons defines the identity of that element (ie, carbon always has 6 protons), but the number of neutrons within that element may vary (carbon-12 and its isotope carbon-13, for example). The number of isotopes each element may have is visually represented by plotting boxes, each of which represents a unique nuclear species, on a graph with the number of neutrons increasing on the abscissa (X axis) and number of protons increasing along the ordinate (Y axis). The resulting chart is commonly referred to as the table of nuclides, and is to nuclear physics what the periodic table of the elements is to chemistry.An arbitrary combination of protons and neutrons does not necessarily yield a stable nucleus. One can think of moving up and/or to the right across the nuclear chart by adding one type of nucleon (i.e. a proton or neutron, both called nucleons) to a given nucleus. However, adding nucleons one at a time to a given nucleus will eventually lead to a newly formed nucleus that immediately decays by emitting a proton (or neutron). Colloquially speaking, the nucleon has 'leaked' or 'dripped' out of the nucleus, hence giving rise to the term ""drip line"". Drip lines are defined for protons, neutrons, and alpha particles, and these all play important roles in nuclear physics. The nucleon drip lines are at the extreme of the proton-to-neutron ratio: at p:n ratios at or beyond the driplines, no stable nuclei can exist. The location of the neutron drip line is not well known for most of the nuclear chart, whereas the proton and alpha driplines have been measured for a wide range of elements. The nucleons drip out of such unstable nuclei for the same reason that water drips from a leaking faucet: in the water case, there is a lower potential available that is great enough to overcome surface tension and so produces a droplet; in the case of nuclei, the emission of a particle from a nucleus, against the strong nuclear force, leaves the total potential of the nucleus and the emitted particle in a lower state. Because nucleons are quantized, only integer values are plotted on the table of isotopes; this indicates that the drip line is not linear but instead looks like a step function up close.