Higher-Order-Filter Velocity Selector for Thermal Neutrons

3He Spin Filter for Neutrons

The strongly spin-dependent absorption of neutrons in nuclear spin-polarized (3)He opens up the possibility of polarizing neutrons from reactors and spallation sources over the full kinematical range of cold, thermal and hot neutrons. This paper gives a report on the neutron spin filter (NSF) development program at Mainz. The polarization technique is based on direct optical pumping of metastab...

Activation Measurements for Thermal Neutrons

The neutron energy spectrum from the atomic bomb consisted of a range of energies from thermal to fast neutrons. Fast neutrons contribute a larger dose to the human body than lowenergy neutrons per unit flux. The evaluation of the fast neutron component has been performed based on analyses of P (>3 MeV) activity measured immediately after the Hiroshima bomb and Ni (>2 MeV), which has a much lon...

Vectorial velocity filter for ultracold neutrons based on a surface-disordered mirror system.

We perform classical three-dimensional Monte Carlo simulations of ultracold neutrons scattering through an absorbing-reflecting mirror system in the Earth's gravitational field. We show that the underlying mixed phase space of regular skipping motion and random motion due to disorder scattering can be exploited to realize a vectorial velocity filter for ultracold neutrons. The absorbing-reflect...

Fast LIC with Higher Order Filter Kernels

Line integral convolution (LIC) has become a well-known and popular method for visualizing vector elds. The method works by convolving a random input texture along the integral curves of the vector eld. In order to accelerate image synthesis signiicantly, an eecient algorithm has been proposed that utilizes pixel coherence in eld line direction. This algorithm, called \fast LIC", originally was...

Strehl Ratio with Higher-Order Parabolic Filter