VX2751

Overview

The VX2751 Digitizer is a 16-channel digital signal processor for radiation detectors in the VME64X form factor. It offers not only waveform digitization and recording but also Multi-Channel Analysis for a complete range of applications like nuclear and particle physics, high-timing resolution, Fast Neutron Spectroscopy, and Homeland Security. It is compliant with fast signals typically coming from organic, inorganic, and liquid scintillators coupled to PMTs or SiPMs, as well as Diamond detectors.

The VX2751 can perform different types of signal processing, basing on algorithms like charge integration and pulse shape discrimination (PSD), constant fraction timing (CFD), and zero-length encoding (ZLE). The algorithm parameters can be set individually for each channel or globally for all channels on the board.

Each channel of the module digitizes the analog input, which can be the signal coming from a physics detector, with a 14-bit 1GS/s ADC. The sampled data are used to initiate the digital pulse processing sequence, managed in the FPGA at the firmware level. Different firmware types can be stored at once on-board and then selected via software, according to the specific setup and acquisition mode.

• Common trigger: All channels acquire simultaneously with a common trigger. The trigger can be fed externally or generated by a combination of individual channel discriminators. This mode is mainly intended for the acquisition of waveforms, like a digital oscilloscope. Options for zero suppression are available to remove not significant data.
• Independent trigger: Suited mode for trigger-less applications, where no global trigger is needed but each channel acquires waveforms upon its self-trigger which fires through a digital discriminator, independently of the others.
• DPP: Real-time processing in the FPGA allows for the extraction of physical parameters from the waveform (e.g. charge, timestamp, PSD), well suited for high counting rate applications. It is yet possible to save both raw waves and parameters.

CAEN provides closed firmware solutions for Scope (waveforms) and DPP modes, as well as a firmware generation and compiling tool for customers who want to personalize the acquisition to implement custom algorithms for pulse processing in the open FPGA. The user can have control of the data output information and customize the trigger logic to get several combinations of self-triggers and I/O signals to validate or discard the events. The Linux-based Arm processor embedded in the onboard CPU makes it possible to run automated user routines. Multi-board synchronization can be implemented via backplane or front panel easy-cabling options. Multiple communication interfaces offer flexible readout options: USB 3.0 type-C and 1/10 Gigabit Ethernet or optional Optical (CONET – CAEN Daisy Chainable Optical Link Protocol) Links.

The VX2751 fits in the single-slot CAEN VME64X u-crate, which allows you to convert the VME digitizer into a desktop board for lab tests.

Moreover, you can check this FAQ to see which CAEN VME crates are suitable for this product.