The model 2401B signal processing and readout electronics require proper matching of the preamp type (either high gain or low gain) to match the desired MCP/RAE sensor head and spatial resolution.  The digitized resolution options for the 2401B will have an effect on the dead-time per event and the overall count rates obtainable.  The dead-time per event for the range from 4 µsec per detected event (basic analog only model and 8-bit digitized option) to 6 µsec (9-bit) and 10 µsec (10-bit), and correspond to maximum output count rates of 100,000 to 60,000 counts/sec with 67% dead time loss with Poisson-distributed event arrival times.

All 2400 series of position analyzers have the following features:
Pulse-pair resolution: 300 nsec. A second event arriving more than 300 nsec but less than 1µsec after a prior event results in both events vetoed from processing; a second event arriving more than 1 µsec but less than the total dead time after a prior event results in the second event vetoed from processing but the first event is processed; events separated by more than the total dead time results in both events processed. If two events arrive within 300 nsec (and combined amplitude does not exceed upper discriminator setting), both events are counted together as a single event with a calculated position between the true positions. Incoming count rates should be adjusted so the probability of near- simultaneous events is minimal.

Inputs: Four low-level charge signals from MCP/RAE sensor (detector head).

X and Y analog position outputs for real-time display: approximately 0.5 to 4.5 VDC linearly proportional to coordinate position of event on sensor.  Analog strobe output and Z-axis blanking output (for XY monitor) activated when valid data is present on analog XY outputs. Quiescent analog X and Y position output voltage is 2.5 volts.

X and Y digitized outputs: TTL-level, positive-true logic outputs, internal 50 pin ribbon connector, external 50-pin Amphenol-type connector. Includes digital strobe.

Front panel edge-gating controls enable selection of rectangular active area for data acquisition.

Other inputs/outputs: Veto Gate Input; Sum (diagnostic gain output), Analog Rate (for remote count rate meter), Analog Strobe, Z-axis Blanking, Rate, and Busy outputs. 1D/2D data switch selector on digitized options. Switch-selectable front-panel meter monitors Count Rate, Input Level (MCP Gain) and Dead-Time Loss %.

Options, 2400 Series

Digitized Output Options

Select digitized output option according to number of digitized position data points (accumulating bins) desired across active diameter of sensor. Recommend using at least 2X (over-sampling) as many digitized data channels as available resolvable elements from sensor (e.g. for standard resolution 100 resolvable element sensor, use 8-bit , 256 channels, digitized output option). Higher-resolution digitized output results in longer total dead time per event and, therefore, lower maximum counting rate capability.