Nuclear decay database in fission product mass region

Accurate and reliable nuclear decay databases are essential for fundamental and applied nuclear research studies.However,decay data are not usually as accurate as expected and need improvement.Hence,a new Chinese nuclear decay database in the fission product mass region(A=66−172)based on several major national evaluated data libraries has been developed under joint efforts in the CNDC working group.A total of 2358 nuclides have been included in this decay database.Two main data formats,namely ENSDF and ENDF,have been adopted.For the total meanβandγenergies,available data from total absorption gamma ray spectroscopy measurements have been adopted.For some nuclides without experimental measurements,theoretically calculated values have been added.

Mapping Nuclear Decay to a Complex Network

Nuclear decay is investigated by the view of network science and the relationship of nuclear decay among different radionuclide can be mapped to a network topology directly.The network includes 1410 nodes and 1275 edges.The average degree of the network of nuclear decay is about 1.8,the cumulative degree distribution still meets the typical power-law distribution,and the corresponding exponent is about 4.1.Not considering their dynamic behavior,the fitting parameters of the nuclear decay network are obtained according to the LUHNM theory proposed by our group before.Their cumulated degree distributions of the nuclear decay network match well.The idea and method may provide a new way to study some other problems of nuclear physics.

Prediction of the Average Decay Heat per Fission for MOX Nuclear Fuel

MIXED Oxide Nuclear fuel (MOX) contains both uranium and plutonium in oxidized form. It is important to calculate the nuclear decay heat due to the single thermal fission (fission due to 0.0235 eV neutron) for all fissile nuclei in the MOX fuels (U235, Pu239, and Pu241). These fissile nuclei are the main source of the decay heat in MOX fuel. Decay heat calculation of the weighted fissile material content in MOX fuel is also important. A numerical method was used in this work to calculate the concentrations of all fission products due to the individual thermal fission of the three fissile materials as a function of time N(t). The decay heat calculations for the three fissile materials are directly calculated using the summation method by knowing the different concentrations of fission products over time. The average decay heat of the MOX fuel in induced thermal fission is also concluded. The most influential nuclei in the decay heat were also identified. The method used has been validated by several comparisons before, but the new in this work is using the most recent Evaluated Nuclear Data Library ENDF/B-VIII.0. Calculations of decay heat show very common trends for a period of 107 sec after the fission burst of thermal fissions of individual fissile nuclei. Moreover, the code showed high capability in calculating the fission fragments inventories and decay heats due to the decay of fission fragments of 31 fissionable nuclei.

Fission Fragment Decay Heat by Using the Most Recent Evaluated Nuclear Data Library ENDF/B-VIII

In this paper, a home-made code was designed to calculate the decay heat emitted by fission fragments as a result of successive radioactive emissions after a fission burst. The nuclear data necessary for the calculations was extracted from the latest version of the Evaluated Nuclear Data Library ENDF/B-VIII.0. The code can calculate the decay heat of thermal and fast neutron-induced fission reactions on the isotopes of Thorium, Protactinium, Uranium, Neptunium, Plutonium, Americium, Curium, California, Einsteinium, and Fermium. A numerical method was used in this work to calculate the decay heat of all fission fragments due to the individual thermal or fast fissions of the isotopes of the previous ten actinides. The most influential nuclei in the decay heat were also identified at different times after the fission event. Moreover, the code showed high capability in calculating the fission fragments inventories and decay heats due to the decay of fission fragments of 31 fissionable nuclei.

The Quantum Chromodynamics Gas Density Drop and the General Theory of Relativity Ether

β decay is one of the most fundamental and thoroughly studied nuclear decay. Surprisingly, the β decay rates were found to have a periodic time variability [1]. However, others argued that there is no evidence for such cyclic deviation from the exponential first order kinetics decay law [2]. Here we propose that the β decay is a pseudo-first order exchange reaction triggered by uddũexotic mesons and propose a QCD gas theory. In analogy to the atmospheric gas density, the proposed QCD gas density drops with elevation from the sun. Accordingly, we propose that the β decay rate periodic variability is due to the pseudo-first order exchange reaction kinetics and the QCD gas atmospheric density drop. The proposed QCD gas may be a possible candidate for Einstein’s general theory of relativity ether [3]. Our main results are the derived formulas for calculating the effective mass of the QCD gas and the cosmology perfect fluid equation of state dimensionless parameter, based on the measured ratio of the β decay rates at the earth trajectory aphelion and perihelion dates. .

A Relativistic Escape Velocity Maximum of Light Speed

There are parallels between the time distortion equations of General and Special Relativity. The time distortion in Special Relativity limits the “Real” velocity of a particle to the speed of light |c| by slowing the velocity of bosons/energy and increasing the mass of fermion||lepton (or matter) particles. In General Relativity, the gravitational slowdown of bosons/gravitons limits the escape velocity |v Esc| to light speed. |v Esc = (2GM/r)0.5| can also be written as |v Esc2 = 2GM/r|. So an alternate grammar for the equation could be The above contests currently held properties of Schwarzschild Objects. Relativistic theory predicts the slowdown of gravitons/bosons, while their velocity only approaches zero. The different mathe-matical logic of Gravitational Force ||GF|| GF = GMm/r2 would mean no limit on the force. Matter formed through compression of bosons can escape after formation by absorbing kinetic energy from the slowing photons/bosons in its surroundings. So matter formation can occur via a steady-state mechanism. The limit on v Esc allows matter to escape in events that parallel both the Big Bang and Cyclic cosmology. Additional arguments are made as to the validity of relativity.

Quenching ofγ0 transition results from 2p-1h doorway mechanism by p-wave neutron excitation

The ratio ofγtransition-intensities from the initial capture state to low-lying states may represent the model-independentγ-strength function,which reflects the effects of different neutron-capture reaction mechanisms.The extraordinary quenching of theγ0 transition from the p-wave neutron radiative capture in 57Fe is observed,for the first time,from the pronounced enhancement of theγ-strength function ratios fγ1/fγ0 and fγ2/fγ0.The 2p-1h doorway excitation leads to suppression of theγ0 transition to the ground state and the enhancement of theγ1 andγ2 transitions to the first and second excited states,respectively.The fp sub-shells supply the exact number of spaces required for the 2p-1h configuration,which features the neutron capture mechanism in the vicinity of A=55.