Neutron star radiation from pulsars is thought to be primarily emitted from regions near their magnetic poles. If the magnetic poles do not coincide with the rotational axis of the neutron star, the emission beam will sweep the sky, and when seen from a distance, if the observer is somewhere in the path of the beam, it will appear as pulses of radiation coming from a fixed point in space (the so-called "lighthouse effect"). The fastest-spinning neutron star known is PSR J1748-2446ad, rotating at a rate of 716 times a second or 43,000 revolutions per minute, giving a linear speed at the
Electron-beam machining to about 200,000 km/s. Magnetic lenses are used to focus the electron beam to the surface of the work-piece. By means of electromagnetic deflection system the beam is positioned as needed, usually by means of a computer. Vacuums must be used to reduce contamination, and minimize electron collisions with air molecules. Because work must be done in a vacuum, EBM is best suited for small parts. The interaction of the electron beam with the work piece produces hazardous x-rays, and only highly trained personnel should use EBM equipment. Electron-beam machining Electron-beam machining (EBM) is a process where high-velocity electrons concentrated