Neutron Halo Isomers in Stable Nuclei and their Possible Application for the Production of Low Energy, Pulsed, Polarized Neutron Beams of High Intensity and High Brilliance

We propose to search for neutron halo isomers populated via $\gamma$-capture in stable nuclei with mass numbers of about A=140-180 or A=40-60, where the $4s_{1/2}$ or $3s_{1/2}$ neutron shell model state reaches zero binding energy. These halo nuclei can be produced for the first time with new $\gamma$-beams of high intensity and small band width ($\le$ 0.1%) achievable via Compton back-scattering off brilliant electron beams thus offering a promising perspective to selectively populate these isomers with small separation energies of 1 eV to a few keV. Similar to single-neutron halo states for very light, extremely neutron-rich, radioactive nuclei \cite{hansen95,tanihata96,aumann00}, the low neutron separation energy and short-range nuclear force allows the neutron to tunnel far out into free space much beyond the nuclear core radius. This results in prolonged half lives of the isomers for the $\gamma$-decay back to the ground state in the 100 ps-$\mu$s range. Similar to the treatment of photodisintegration of the deuteron, the neutron release from the neutron halo isomer via a second, low-energy, intense photon beam has a known much larger cross section with a typical energy threshold behavior. In the second step, the neutrons can be released as a low-energy, pulsed, polarized neutron beam of high intensity and high brilliance, possibly being much superior to presently existing beams from reactors or spallation neutron sources.Comment: accepted for publication in Applied Physics

Singularities of moving-conductor properties of fractal composite materials with a-radioactive inclusions

Рассмотрены особенности влияния неравновесности и фрактальности среды на распространение и поглощение электромагнитных волн во фрактальных композитных материалах с радиоактивными включениями. На основе аппарата дробных производных предложена модель, описывающая радио-физические процессы в устройстве с фрактальными элементами.Розглянуто особливості впливу нерівноваги і фрактальності середовища на поширення і поглинання електромагнітних хвиль у фрактальних композитних матеріалах з радіоактивними включеннями. На основі апарата дробових похідних запропонована модель, що описує радіофізичні процеси в пристрої з фрактальними елементами.The singularities of influence of a non-equilibrium and fractal of a medium on distribution and absorption of electromagnetic waves in fractal composite materials with a-radioactive inclusions surveyed. On the basis of a means fractional derivative the model circumscribing radiophysical processes in the device with fractal units is offered