Cross Section for “Ultracold” Neutrons
نویسنده
چکیده
Very cold neutrons (typical wavelengths are about 102 Ä) are available by recently developed techniques 2. The features of the scattering of these “ultracold” neutrons are investigated in the present paper discussing a few examples of magnetic scattering. The diffraction of neutrons by the vortex lattice in superconductors is treated as an example of elastic scattering, while in most other cases the scattering is inelastic. We discuss the scattering by ferromagnetic magnons at low temperatures and the critical scattering from an isotropic ferromagnet above the critical tempera ture. Simple models are used to derive the total cross sections. It is shown that relevant information about the inealsticity can be gained by the measurement of total cross sections in these cases.
منابع مشابه
- th / 9 90 70 83 v 1 2 1 Ju l 1 99 9 Multiple scattering theory for slow neutrons ( from thermal to ultracold )
The general theory of neutron scattering is presented, valid for the whole domain of slow neutrons from thermal to ultracold. Particular attention is given to multiple scattering which is the dominant process for ultracold neutrons (UCN). For thermal and cold neutrons, when the multiple scattering in the target can be neglected, the cross section is reduced to the known value. A new expression ...
متن کاملComment on "giant absorption cross section of ultracold neutrons in gadolinium".
Rauch et al [1] have measured the absorption cross section of natural Gd and isotopically enriched Gd for neutron energies extending into the ultracold energy region [2] using Gd compounds dissolved in D2O. For the case of Gd the result for neutrons with a velocity of 10 m/sec (49.7 Mbarns) was found to be less than the value obtained by extrapolating the value at thermal energies (v = 2200 m/s...
متن کاملRotational Effects of Nanoparticles for Cooling down Ultracold Neutrons
Due to quantum coherence, nanoparticles have very large cross sections when scattering with very cold or Ultracold Neutrons (UCN). By calculating the scattering cross section quantum mechanically at first, then treating the nanoparticles as classical objects when including the rotational effects, we can derive the associated energy transfer. We find that rotational effects could play an importa...
متن کاملبهینه سازی انرژی باریکه نوترون در نوترون درمانی با بور با روش مونت کارلو
In last two decades the optimal neutron energy for the treatment of deep seated tumors in boron neutron capture therapy in view of neutron physics and chemical compounds of boron carrier has been under thorough study. Although neutron absorption cross section of boron is high (3836b), the treatment of deep seated tumors such as gliobelastoma multiform (GBM) requires beam of neutrons of higher ...
متن کاملAn ultracold neutron source at the NC State University PULSTAR reactor
Research and development is being completed for an ultracold neutron (UCN) source to be installed at the PULSTAR reactor on the campus of North Carolina State University. The objective is to establish a university-based UCN facility with sufficient UCN intensity to allow world-class fundamental and applied research with UCN. To maximize the UCN yield, a solid ortho-D2 converter will be implemen...
متن کامل