A complementary metal-oxide-semiconductor anode array chip with two rows of 512 anodes and dual integrated analog read-out circuitry

A novel multianode electron detector chip (LEDA512) has been designed, fabr icated and tested using a 0.7 mum complementary metal-oxide-semiconductor t echnology. This chip, mounted behind a stack of two microchannel plates, is used in a positive ion mass spectrometer selected by the European Space Ag ency for the ROSETTA cometary mission. Two functions are integrated on the chip: a dual row of 512 anodes, each having an area of 22 mu mx8 mm for the collection of electrons, and two separate anode multiplexer and charge amp lifier units. For redundancy reasons the chip has been designed such that t he two anode rows with their associated electronics are identical and may b e used independently with separate clocks and power supplies. Tests have co nfirmed that the LEDA512/microchannel plate combination is working properly as an ion detector and that excellent noise and response may be obtained i n combination with the mass spectrometer. (C) 2000 American Institute of Ph ysics. [S0034-6748(00)04511-1].