VX2730

Overview

The VX2730 Digitizer is a 32-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 mid-fast signals typically coming from liquid or inorganic scintillators coupled to PMTs or SiPMs, but also for high-precision detectors like Silicon or HPGe.
Independently for each of the 32 channels, the VX2730 can perform signal processing based on algorithms for different kinds of measurements (e.g. DPP-PHA for pulse height analysis, DPP-PSD for pulse shape discrimination, data reduction).
Each channel of the module digitizes the analog input, which can be the signal coming from a physics detector, with a 14-bit, 500MS/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. pulse height, 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 VX2730 is compliant with the single-slot CAEN VME64X u-crate making it possible to turn the VME digitizer into a desktop operating board for laboratory experiences.