background: in high-intensity, mixed and pulsed neutron fields the use of spectrometers or area monitors with active detectors is useless in these conditions neutron measuring devices must have a passive detector. here a passive neutron area monitor with cr39 track detector was designed and the response was calculated. materials and methods: the response of a passive neutron area monitor with c...

Due to hydrogen possessing a relatively large neutron scattering length, hydrogen absorption and desorption behaviors in metal thin films can straightforwardly be investigated by neutron reflectometry. However, to further elucidate the chemical structure of the hydrogen absorbing materials, complementary techniques such as high resolution X-ray reflectometry and diffraction remain important too...

We present spectroscopy and imaging with the Very Large Telescope (VLT) of the neutron star RX J1856.5−3754. Little is known about the nature of this source other than that it is a nearby hot neutron star. Our VLT spectrum does not show any strong emission or absorption features. With considerable care to photometric calibration, we obtain photometric measurements over the optical and ultra-vio...

We present spectroscopy and imaging with the Very Large Telescope (VLT) of the isolated neutron star RX J1856.5−3754. Little is known about the nature of this source other than that it is a nearby hot neutron star. Our VLT spectrum does not show any strong emission or absorption features. With considerable care to photometric calibration, we obtain photometric measurements over the optical and ...

Neutronirradiation effects on optical absorption of solid-state nuclear track detector, CR-39 was studied for the various fluences ranging from 2.38x106 to 2.7x108 n/cm by ultraviolet-visible (UVVis) spectroscopy. The optical absorption spectra in the wavelength range of 200-700nm were recorded for the pristine and the neutron irradiated samples in the above fluence range. The UV-visible spectr...

The large spin dependence of the absorption cross section for neutrons by He gas provides a method to polarize neutron beams. For certain applications, such polarized He-based neutron ”spin filters” have advantages over conventional neutron optical polarizing methods. Spin filters operate at all neutron wavelengths, can cover a large angular range and/or a large energy range, and decouple neutr...

This paper reviews the following problems, sampling, decomposition procedures and most important analytical methods used for selenium determination, e.g., neutron activation analysis, atomic absorption spectrometry, gas-liquid chromatography, spectrophotometry, fluorimetry, and x-ray fluorescence. This review covers the literature mainly from 1975 to 1977.

In proto-neutron stars with strong magnetic fields, the neutrino-nucleon scattering/absorption cross sections depend on the direction of neutrino momentum with respect to the magnetic field axis, a manifestation of parity violation in weak interactions. We study the deleptonization and thermal cooling (via neutrino emission) of proto-neutron stars in the presence of such asymmetric neutrino opa...