MTDC-64 Description

MTDC-64 is a 64-channel, 100 ps time-stamping TDC with PCI-Express interface designed to Time-Of-Flight spectroscopy in nuclear physics. It is targeted for production testing of particle detectors: straw tubes, gas-filled drift chambers, scintillator counters, neutron counters.

Unlike traditional rack based TDC electronics, this board allows building of the complete time digitizer system in portable compact size PC. This is ideal for medium channel count test setups. Multiple MTDC-64 boards may be connected with the internal extension bus for larger channel count.

Time to Digital converter module MTDC-64 is based on High Performance general purpose TDC (HPTDC) developed at CERN. It is a time-stamping TDC, the device measures arrival time of input pulses. The internal time-stamp counter is reset on synchronization signal (burst reset). Two HPTDC chips allows simultaneous acquisition of 64 input channels. The step of time scale is 100 ps.

The MTDC-64 device allows multiple pulses on every channel to be measured, the total number of measurements limited by buffer size is 512. Double-pulse resolution is 5 ns typical, 10 ns guaranteed.

There is a dedicated channel 0 for Start-Stop mode measurements. The common signal is fed to channel 0 and the software decodes time-stamp data relative to channel 0 time-stamp.

Three trigger modes are available with the device: external trigger, logic OR on all inputs and test mode with internal asynchronous generator. In external trigger mode the device measures the pulses that has arrival time in defined range relative to trigger signal. In internal trigger mode any input pulse starts the measurement. Test mode is used for count rate measurements. The device has internal memory that allows measurement of signals delayed from trigger signal by 100 μs. This time range is programmable with steps of 0.025 μs.

The universal input stage of MTDC-64 module handles differential signals both positive and negative polarity, it is ECL, PECL, LVDS compatible. NIM and other single-ended signals may be connected with transformer coupling.

Data readout is performed with PCI-Express interface. The control software is used to set synchronization and trigger mode, time resolution and acquisition range. Individual channels may be masked to suppress overflows in case of oscillation.

The raw data is processed and analyzed by the software. Built-in histograms shows the arrival time of pulses, time-of-flight in external trigger mode, pulse count for channels and data throughput. The raw data and configuration is also stored in files for external analysis software.