ADCM

ADCM is the compact and universal Digital Pulse Processing system for nuclear physics experiments.

Applications

• Fast Scintillators Spectroscopy
• Silicon Photomultiplier Front-End
• Applied Particle Imaging with Tagged Neutron Beam

Features

• 14 bit, 1.5 LSB RMS amplitude resolution
• 18 picoseconds RMS time resolution
• 16 channels on PCI card, extendable up to 4 cards
• Baseline recovery and pile-up rejection
• 100 MS/s waveform sampling rate
• Parallel pipelined FPGA pulse processing
• User configurable trigger matching logic

Supported Hardware

• ADCM-16

• ADCM16-LTC

• ADCM16-3

• 8CADC

Theory of Operation

• Continuous sampling, pipeline architecture
• FIR filter pulse shaping
• Digital Constant Fraction discriminator

ADCM has the universal Digital Pulse Processing architecture. The hardware data acquisition board ADCM16-LTC utilizes high speed ADC for sampling of input signals. First level trigger logic performs zero suppression by threshold crossing method with hysteresis. Second level trigger logic (when enabled) measures the arrival time of input signals in coarse scale and the coincidence logic produce match output signal for data taking start.

Thoroughly optimized software pulse processor is designed for extra precision measurements. The software is capable of 100,000 pulses per second when running on 3 GHz CPU. The time resolution achieved by software pulse reconstruction algorithm is the best over other known methods. ADCM pulse processor utilize real-time least square minimization method for gaussian-like pulse parameter evaluation. Other methods, including parabolic approximation, does not give enough resolution and have bad DNL (differential nonlinearity) in comparison to iterative minimization method.

ADCM Software

We have developed the software for complex signal analysis including charge spectrometry and Time-Of-Flight measurements. One of the key features is precision sub-sample timing of signals using a variant of digital constant fraction discriminator.

The signal parameters are presented in live histograms and stored in data file. Histograms are shown for main measured parameters: amplitude (integral), time difference.

The software package has two parts: the lowlevel kernel driver and GUI control panel. We have a bootable LiveCD and LiveUSB flashdrive for no-harddisk installations.

Requirements: Intel Pentium-4 2.0GHz, 512MB RAM, CD/DVD drive (for LiveCD) or USB port (for LiveUSB), PCI slot.

Data File Format

• ADCM Data File Format

• ADCM Raw Data File Format

Screenshots

Main: Oscilloscope mode, trheshold control, trigger setup

Statistics: Baseline, noise, hit counters

Histograms in main window

Signal reconstruction setup: FIR filters, integration range, pile-up detector

Completed Setups

• DVIN - API (Applied Particle Imaging), explosives and drugs detector