Radio-quiet neutron star ten bodies have been proposed as rotation-powered neutron stars that are not visible as radio sources, but are visible as x–ray and gamma ray sources. Indicators that they are indeed neutron stars include them having a high x-ray to lower frequencies emission ratio, a constant x-ray emission profile, and coincidence with a gamma ray source. Quark stars, theoretical neutron star-like objects composed of quark matter, may be radio quiet, according to some theories. More plausibly, however, radio-quiet neutron stars may simply be pulsars which do not pulse in our direction. As pulsars spin, it is theorized they emit radiation from
Proximity effect (electron beam lithography) and formula_4 are determined by the resist and substrate materials and the primary beam energy. The two-gaussian model parameters, including the development process, can be determined experimentally by exposing shapes for which the Gaussian integral is easily solved, i.e. donuts, with increasing dose and observing at which dose the center resist clears or does not clear. A thin resist with a low electron density will reduce forward scattering. A light substrate (light nuclei) will reduce backscattering. When electron beam lithography is performed on substrates with 'heavy' films, such as gold coatings, the backscatter effect will (depending on thickness) significantly increase.