FADC250 Data Processing Application

A JANA2-based application for processing FADC250 detector data from EVIO-format files. For now, the application supports extracting and decoding FADC250 data only if each EVIO event contains exactly one detector event.

Data Processing Flow

1. Event Source reads EVIO files, extracts run numbers from control events (skipping them), and adds physics events to the processing queue
2. Factory fetches these events and passes them to the EVIO event parser
3. EVIO Event Parser does EVIO event level parsing and delegates raw data parsing to Raw Data Parser
4. Raw Data Parser parses raw data and creates hit objects with extracted data
5. Processor consumes these hit objects and outputs the results to a ROOT file

Hardware Configuration

This application was developed and tested using data from following:

• FADC250 Module: 1 unit at crate 1, slot 3
• Data Bank ID: 250
• Operating Mode: 10

Prerequisites

Before building this application, ensure you have:

• CMake 3.16 or higher
• C++20 compatible compiler
• Git (for cloning dependencies)
• ROOT 6.3x.x (for data analysis and visualization)

Dependencies

This project requires the following dependencies:

1. JANA2 Framework

JANA2 provides the core event processing framework for this application.

Building JANA2

git clone https://github.com/JeffersonLab/JANA2.git JANA2
cd JANA2
cmake -S . -B build -DCMAKE_INSTALL_PREFIX=`pwd`
cmake --build build --target install -j 20

2. EVIO Library

The EVIO library is required for reading and parsing EVIO format data files.

Building EVIO

git clone https://github.com/JeffersonLab/evio/
cd evio
git checkout v6.1.2
cmake -S . -B build
cmake --build build --target install --parallel

3. Building ROOT

For ifarm users: Use the pre-built version at /group/halld/Software/builds/Linux_Alma9-x86_64-gcc11.5.0/root/root-6.32.08

For other systems: Install ROOT following the guide at https://root.cern/install/

Building the Application

Build Instructions

1. Configure the build:

cmake -S . -B build -DCMAKE_PREFIX_PATH="/path/to/JANA2;/path/to/EVIO/Linux-x86_64;/path/to/ROOT"

Replace the paths with your actual installation directories:

• /path/to/JANA2 - Your JANA2 directory
• /path/to/EVIO - Your EVIO directory
• /path/to/ROOT - Your ROOT installation (on ifarm set it to /group/halld/Software/builds/Linux_Alma9-x86_64-gcc11.5.0/root/root-6.32.08)

2. Build the application:

cmake --build build --parallel

Build Types: Add -DCMAKE_BUILD_TYPE=Debug for debugging or -DCMAKE_BUILD_TYPE=Release for optimized builds.

Complete Build Sequence

# 1. Build JANA2
git clone https://github.com/JeffersonLab/JANA2.git JANA2
cd JANA2
cmake -S . -B build -DCMAKE_INSTALL_PREFIX=`pwd`
cmake --build build --target install -j 20
cd ..

# 2. Build EVIO
git clone https://github.com/JeffersonLab/evio/
cd evio
git checkout v6.1.2
cmake -S . -B build
cmake --build build --target install --parallel
cd ..

# 3. Build application (adjust ROOT path as needed)
cd compton_exp
cmake -S . -B build -DCMAKE_PREFIX_PATH="/path/to/JANA2;/path/to/EVIO/Linux-x86_64;/path/to/ROOT"
cmake --build build --parallel

Note: ROOT installation is not shown here. On ifarm, use the pre-built version. On other systems, install ROOT first (see Dependencies section).

Usage

After building, run the application with:

./build/compton [jana_options] <evio_file1> [evio_file2] ...

The application will process the specified EVIO files and create a ROOT output file (compton.root) containing:

• Waveform TTree (waveform_tree): Channel-by-channel waveform data with branches for slot, channel, and waveform samples
• Pulse Integral Histogram (h_integral): Distribution of pulse integral sums

Customizing Output Filename

You can specify a custom ROOT output filename:

# Customize ROOT output filename
./build/compton -PROOT_OUT_FILENAME=my_data.root <evio_file>

Project Structure

Core Application Files

• compton.cc – Main application entry point
• JEventSource_EVIO.cc/.h – Custom EVIO event source
• JEventProcessor_Compton.cc/.h – Main event processor
• JFactory_FADC250.cc/.h – Factory for FADC250 detector data

Data Objects (data_objects/)

• EventHits.h – Container for all event hits
• EvioEventWrapper.h – Wrapper for EVIO event data
• FADC250Hit.h – Base class for all FADC250 hits
• FADC250PulseHit.h – Pulse hit data structure
• FADC250WaveformHit.h – Waveform hit data structure

Parser Utilities (parsers/)

• EvioEventParser.cc/.h – EVIO event parsing utilities
• RawDataParser.cc/.h – Raw data parsing utilities