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18

A lot of different forms, but mostly kinetic energy. A good table is given at Hyperphysics. The energy released from fission of uranium-235 is about 215 MeV. This is divided into: Kinetic energy of fragments (heat): ~168 MeV Assorted gamma rays: ~15-24 MeV Beta particles (electrons/positrons) and their kinetic energy: ~8 MeV Assorted neutrons and their ...


5

In general, decays which release a lot of energy are faster than than decays which release only a little energy. As Carl Witthoft points out, the first excited state is unlikely to decay to the ground state partially because the energy difference is small, and partially because the spin difference is large. (The photon for the $5^+\to1^+$ transition within ...


4

Nuclei have a series of discrete energy levels (somewhat analogous to electronic energy levels, but the details are, not surprisingly, different). Examples of these so-called Energy Level Diagrams can be found at, e.g., Triangle Universities Nuclear Laboratory. So, a simple alpha decay will go from one level in the parent nucleus to one level in the daughter ...


3

Not a definitive answer, but I note the following. The solar photospheric abundance of Thorium is indistinguishable from the abundances in the protosolar nebula deduced from meteorites (to within 0.1 dex, Asplund et al. 2009). Of course it might be thought possible that Th-depleted material in the centre of the Sun never makes it to the photosphere. ...


3

The mass of an atom is always less than the sum of the masses of the particles that compose it. The lack of mass (or energy, from E = mc^2) is called binding energy and it is the energy expended by the particles to remain confined inside of the atom. When fission occurs, not more spending of energy to hold together the individual particles. So the energy ...


3

The energy that is released when a the absorption of a neutron causes a heavy atom nucleus to fission into two daughter nuclei comes from the tighter binding energy of the two daughter nuclei compared to the weaker (smaller) binding energy of the original nucleus. This extra energy is mostly released in the form of the kinetic energy of the two daughter ...


3

The sun's core has a density of of 150 g/cm³ (150 times the density of liquid water) at the center, and a temperature of close to 15,700,000 kelvin, or about 15,700,000 degrees Celsius; by contrast, the surface of the Sun is close to 6,000 kelvin. The core is made of hot, dense gas in the plasmic state, at a pressure estimated at 265 billion bar (26.5 ...


3

The big mystery is: why should nature prefer one direction over another? And the answer is still unknown. From wikipedia: The experiment's purpose was to establish whether or not conservation of parity (P-conservation), which was previously established in the electromagnetic and strong interactions, also applied to weak interactions. If ...


3

The short answer is that the deformation parameters are related to the diagonal matrix elements of the multipole operators, while the reduced transition probabilities $B(El)$ are related to the off-diagonal matrix elements. As a specific example, the quadrupole moment (directly related to the deformation parameter $\beta$) of a nucleus in its ground state ...


2

The odd-ordered transitions don't vanish — they just have odd parity, and so they are only permitted between states with different parity. For instance a $1^-\to0^+$ transition will be mostly electric dipole (E1) with some smaller contribution from M2 and E3. A $1^+\to0^+$ transition, by contrast, will be a mixture of M1 and E2 (also with smaller ...


2

I'm not an expert on the notation, but I think the answer you're after is this info, from Trent U. Physics Lab Notes. Sorry about the loss of formatting. In this experiment foils of the stable element 49 115 In are bombarded by neutrons produced in a radioactive source (described below). The reaction is 0 1 49 115 49 116,m n + In In The m indicates that ...


2

The charge density stems entirely from the charged particles in the nucleus, but the higher moments depend largely (in a sense, "entirely") on their arrangement. Placing 8 protons at the vertices of a cube produces notably different higher moments than, say, placing all along a line segment, or in an octagon. (This should be apparent from the different ...


1

In atomic physics, we have Hund's rules which tell us whether the next electron added to an atom will fill an $s,p,d,f$ orbital. One consequence of the Wigner-Eckart theorem is that the angular momentum of an object constrains its multipolarity. A spinless object may carry only monopole moment; a spin-half object may carry monopole and dipole moments, but ...


1

The ground state nuclear spin quantum number and parity, $J^{\pi}$ for all even-even nuclei is $0^+$. The isospin can vary, but for the ground state of even-even will probably be either 0 or 1. The isospin quantum number, $I$, is limited to the range of $$\frac{|Z-N|}{2}\le I \le \frac{Z+N}{2}.$$ The $J$ for odd-mass-number nuclei will be a half-integer ...


1

You should just think of Deuterium burning as a short-lived counterpart of main sequence hydrogen burning. As the pre-main-sequence star (PMS star, or protostar if you like) contracts, its core reaches around $6\times 10^{5}$ K and D burning is smoothly initiated. The star is then held at roughly constant luminosity and radius, because if it contracted, the ...


1

In order to answer this question for a fissionable material, you need to know the cross section for neutron-induced fission, the number of free neutrons released in a typical fission event, and the energies that the neutrons are born with. For instance, the evaluated nuclear data file for uranium-235 lists a fission cross section of 1 barn for 10 MeV ...


1

The short answer is that all transitions which are not forbidden by parity or angular momentum conservation happen, though not necessarily at the same rate. When several multipolarities are allowed, the one with the lowest multipolarity dominates.


1

The Hartree-Fock method treats the interaction between particles in a mean-field approximation. So the potential felt by particle i is given by the average over the wave functions of all the other particles. However - speaking semi-classically - you could imagine that particle j has a position as a function of time, and when it's on the "left" side of the ...


1

Apparently, the CANDU reactor can accept a variety of fuels, including what would be considered "waste" from other reactor types, although some amount of reprocessing is involved.


1

The test was not written by my teacher, so he had no answer and he did not notice it either. But after a while, we thought that photons are not realy elementry particles (or classical ones), like neutrons or protons. And the question states 3 more unknown particles. So maybe photons dont apply to that condition. But this is not a real answer, since the ...


1

In the nuclear shell model, you can assign "orbitals" to each nucleon analogous to the orbitals assigned to electrons. Like the electrons, you can promote a nucleon into an empty orbital above the Fermi energy by exciting the nucleus with a photon — a gamma ray rather than a visible photon. The structure of the energy levels is pretty complicated: much more ...


1

I describe this in my book "Guesstimation 2.0" (Princeton University Press, 2012). The work done by the expanding shock wave is pressure times change in volume. The change in volume is as described by the previous answer: 2.5 m * 2pi * (16 km)^2. Fermi could feel the extra pressure due to the explosion, we can only estimate it. The extra force on his ...


1

There are a couple of related questions: What elements can be created in the fusion process of different types of stars? What is the heaviest element possible produced in a supernova? though surprisingly I can't find an exact duplicate (which probably just means I didn't look hard enough). Iron is the most stable nucleus so in principle all other nuclei ...



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