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It is well known that two fission fragments (FFs) are emitted essentially back to back in the laboratory frame. That can be used widely in many applications as a unique signature of fissionable materials. However, such fission fragments are difficult to detect. The energy and angular distributions of neutrons, on the other hand, are easy to measure, and that distribution will carry information about the fission fragments energy and angular spectra, as well as the neutron spectra in the fission fragment rest frame. We propose to investigate the two neutron correlation yield resulting from two FFs as a function of different targets, the angle between the two neutrons and the neutron energies. The preliminary calculation of the two neutron correlation shows a huge asymmetry effect: many more neutrons are emitted anti-parallel to each other than parallel to each other. That asymmetry becomes even more if the energy cut on each neutron is done. This study will potentially permit a new technique for actinide detection for homeland security and safeguards applications as well as improve our knowledge of correlated neutron emission.
We have calculated the fission probabilities for 237-Np, 233,235,238-U, 232-Th, and nat-Pb following the absorption of photons with energies from 68 MeV to 3.77 GeV using the RELDIS Monte-Carlo code. This code implements the cascade-evaporation-fissi
A new technique was developed to measure the lifetimes of neutron unbound nuclei in the picosecond range. The decay of 26O -> 24O+n+n was examined as it had been predicted to have an appreciable lifetime due to the unique structure of the neutron-ric
The photofission cross-section of 238U was measured at sub-barrier energies as a function of the gamma-ray energy using, for the first time, a monochromatic, high-brilliance, Compton-backscattered gamma-ray beam. The experiment was performed at the H
The aCORN experiment uses a novel asymmetry method to measure the electron-antineutrino correlation (a-coefficient) in free neutron decay that does not require precision proton spectroscopy. aCORN completed two physics runs at the NIST Center for Neu
We have investigated experimentally the pressure dependence of the production of ultracold neutrons (UCN) in superfluid helium in the range from saturated vapor pressure to 20bar. A neutron velocity selector allowed the separation of underlying singl