Hamamatsu Photonics has introduced the silicon photodiodes in two formats: the S11141, a 10x10mm single element and the S11142, a 14x14mm quadrant type. The quadrant type allows detection of the reflected electron beam position. Both diodes have a 2mm diameter centre hole, to allow the main electron beam to pass through the sensor. They are designed to detect electrons with energies from 2keV up to more than 30keV. At 5keV, the diodes feature a gain of 1100. The diodes have been optimised for back scatter measurements inside scanning electron microscopes. The packaging and metal contacts are designed to be non-magnetic, so they have no external influence on electron beam trajectories, says the company. The stability and reliability of the diodes make them suitable for all electron detection applications, says the company.
