Abstract: An electron multiplier is disclosed having separate detector and conversion dynode elements. A single power supply external to the electron multiplier is used to bias the detector element. A DC-to-DC voltage converter within the electron multiplier is responsive to the detector bias voltage for converting this voltage to a greater value that is used to bias the conversion dynode.

Abstract: A series of improved electron multipliers is shown which are capable of reducing the number of bombardments per unit area. In the preferred embodiment, the inner channel is significantly increased in surface area over that surface area of present-day multipliers. Because the surface area is increased, for the same charge throughout, the number of electron bombardments per unit area is decreased. Since the number of bombardments per unit area is reduced, there is less degradation on the inner surface of the channel and hence the device lifetime is also increased.

Abstract: A segmented electron multiplier is disclosed with front and rear sections. The sections are specially designed so that the length of the rear section compared to the length of the front section is no less than 4:1. This permits multiple replacements of the rear section, after the multiplier wears out, without any unsatisfactory drop in the overall electrical gain produced by the repaired device. In the preferred embodiment, the front portion is a funnel having a tubular stem, and the rear portion is a straight tube with a cylindrical helical inner channel. The length-to-length split is 5:1, which theoretically permits up to six or seven replacements of the rear section before unsatisfactory gain occurs.