N840

Overview

The CAEN Mod. N840 is an 8 Channel Leading Edge Discriminator housed in one unit wide NIM module. The module accepts 8 negative inputs and produces 2×8 NIM outputs (NIM outputs are provided with a fan-out of two)+ 8 /NIM outputs (negated) on front panel LEMO 00 connectors.
The pulse forming stage of the discriminator produces an output pulse whose width is adjustable in a range from 5 ns to 40 ns. Each channel can work both in Updating and Non-Updating mode according to on-board jumpers position. The discriminator thresholds are individually settable in a range from -1 mV to -255 mV (1 mV step), via an 8-bit DAC. The minimum detectable signal is -5 mV. The back panel houses VETO and TEST inputs, the OR output and the Current Sum output, which generates a current proportional to the input multiplicity, i. e. to the number of channels over threshold, at a rate of -1.0 mA per hit (-50 mV per hit into a 50 Ω load) ±20%.