The Evolution and Explosion of Massive Stars
... temperature. Since nuclear reactions occur at rates that are very sensitive to the temperature, this causes an increase in the burning. New elements are created in seconds that it might otherwise have taken weeks and months to synthesize. ...
... temperature. Since nuclear reactions occur at rates that are very sensitive to the temperature, this causes an increase in the burning. New elements are created in seconds that it might otherwise have taken weeks and months to synthesize. ...
Unified Description of Neutrino-Nucleus Interactions within Nuclear
... . The SuperKamiokande detector, in Japan, is filled with 12.5 million gallon of ultra-clean water . The MiniBooNE detector,at FNAL, is filled with 800 tons of mineral oil . The detected signal results from neutrino interactions with Oxygen and Carbon nuclei . A quantitative understanding of the thei ...
... . The SuperKamiokande detector, in Japan, is filled with 12.5 million gallon of ultra-clean water . The MiniBooNE detector,at FNAL, is filled with 800 tons of mineral oil . The detected signal results from neutrino interactions with Oxygen and Carbon nuclei . A quantitative understanding of the thei ...
Dark Matter
... Part III. Answer these brief questions (taken from Bennett’s textbook) #4. Are all neutron stars also pulsars? Explain. Does It Make Sense? Decide whether each of the following statements makes sense (is clearly true) or does not make sense (is clearly false). Explain your reasoning thoroughly. #5. ...
... Part III. Answer these brief questions (taken from Bennett’s textbook) #4. Are all neutron stars also pulsars? Explain. Does It Make Sense? Decide whether each of the following statements makes sense (is clearly true) or does not make sense (is clearly false). Explain your reasoning thoroughly. #5. ...
Neutron Stars
... The energy source for the repeated gamma-ray bursts (SGRs) from some neutron stars is what? A: fusion of hydrogen on the surface B: energy released by material accreting onto the surface. C: the result of reconfigurations of the strong magnetic fields ...
... The energy source for the repeated gamma-ray bursts (SGRs) from some neutron stars is what? A: fusion of hydrogen on the surface B: energy released by material accreting onto the surface. C: the result of reconfigurations of the strong magnetic fields ...
Helical Particle Waves
... and its internal objects are oscillating all the time. While the two [+] objects represent the two protons that determine the kind of element as Helium, the other two [±] objects represent the two neutrons that prevent these two positively charged protons from flying away. The neutrons continuously ...
... and its internal objects are oscillating all the time. While the two [+] objects represent the two protons that determine the kind of element as Helium, the other two [±] objects represent the two neutrons that prevent these two positively charged protons from flying away. The neutrons continuously ...
Toward a Global Description of the Nucleus
... degenerate electron gas. Electron screening effects become so strong that rates of nuclear reactions increase considerably even at low energies; Pycnonuclear reactions take place under very high density conditions and are more sensitive to density than to temperature – from the Greek, pyknos means c ...
... degenerate electron gas. Electron screening effects become so strong that rates of nuclear reactions increase considerably even at low energies; Pycnonuclear reactions take place under very high density conditions and are more sensitive to density than to temperature – from the Greek, pyknos means c ...
Introduction to Nuclear Forces
... sometimes contain a ! 0 - meson and sometimes contain a ! + - meson. Of course, the nucleon must absorb the meson it has emitted within a very short time, but then it can emit another one. Similarly, the meson field surrounding an isolated neutron should sometimes contain a ! 0 meson and sometimes a ...
... sometimes contain a ! 0 - meson and sometimes contain a ! + - meson. Of course, the nucleon must absorb the meson it has emitted within a very short time, but then it can emit another one. Similarly, the meson field surrounding an isolated neutron should sometimes contain a ! 0 meson and sometimes a ...
Unit 2: The Sun and Other Stars
... by the star (which we call a supernova). While scientists still don’t completely understand the process, the collision of neutron stars and supernova explosions appear to be the “creators” of the heavier elements. ...
... by the star (which we call a supernova). While scientists still don’t completely understand the process, the collision of neutron stars and supernova explosions appear to be the “creators” of the heavier elements. ...
Home | STA Notes
... Clearly the universe cannot be younger than the objects in it - and some galaxies have been reliably measured to be 15-17 billion years old - which puts the lower value for the age of the universe in doubt. There is also uncertainty and controversy about the ultimate fate of the universe. This depen ...
... Clearly the universe cannot be younger than the objects in it - and some galaxies have been reliably measured to be 15-17 billion years old - which puts the lower value for the age of the universe in doubt. There is also uncertainty and controversy about the ultimate fate of the universe. This depen ...
Section 46.6 Strange Particles and Strangeness
... arrival times could show scatter simply because neutrinos were created at different moments as the core of the star collapsed into a neutron star. If neutrinos have nonzero mass, then lower-energy neutrinos should move comparatively slowly. The data are consistent with a 10-MeV neutrino requiring at ...
... arrival times could show scatter simply because neutrinos were created at different moments as the core of the star collapsed into a neutron star. If neutrinos have nonzero mass, then lower-energy neutrinos should move comparatively slowly. The data are consistent with a 10-MeV neutrino requiring at ...
Iron in Stars
... mass of the Sun. At this mass, electron degeneracy pressure is overcome. This is the pressure caused by the Pauli Exclusion Principle which forbids fermions (such as electrons) being in the same energy state. It is an extremely strong force but can be overcome. At this point, electrons and protons c ...
... mass of the Sun. At this mass, electron degeneracy pressure is overcome. This is the pressure caused by the Pauli Exclusion Principle which forbids fermions (such as electrons) being in the same energy state. It is an extremely strong force but can be overcome. At this point, electrons and protons c ...
CHAPTER 2 The nucleus and radioactive decay - Cin
... particles by considering the energies of particles in nuclear reactions by assuming energy and mass are interchangeable (E=mc2, where E is energy, m is mass, and c is the speed of light). Regardless of the approach, all masses are calibrated against 12C. On such a scale the proton is 1.00727647 u, t ...
... particles by considering the energies of particles in nuclear reactions by assuming energy and mass are interchangeable (E=mc2, where E is energy, m is mass, and c is the speed of light). Regardless of the approach, all masses are calibrated against 12C. On such a scale the proton is 1.00727647 u, t ...
Atoms
... Symbols for the various atoms are usually written in the form ZA X , where X is the one- or twoletter symbol for the atom. For example, 12 6 C denotes a carbon atom with a mass number of 12. (The text omits the atomic number from the symbol). Each atom has a different atomic number Z. This is becaus ...
... Symbols for the various atoms are usually written in the form ZA X , where X is the one- or twoletter symbol for the atom. For example, 12 6 C denotes a carbon atom with a mass number of 12. (The text omits the atomic number from the symbol). Each atom has a different atomic number Z. This is becaus ...
"Strange nuclear materials"()
... need inducement before they will eject particles. In fact, any nucleus can be broken apart by hitting it hard enough with another nucleus. This can be done in the laboratory by using high energy particles from accelerators, but it also happens naturally in stars. Nuclear reactions were important eve ...
... need inducement before they will eject particles. In fact, any nucleus can be broken apart by hitting it hard enough with another nucleus. This can be done in the laboratory by using high energy particles from accelerators, but it also happens naturally in stars. Nuclear reactions were important eve ...
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.