Calorimeter Geometry Viewer

Web

A web-based 3D visualization tool for CERN ATLAS calorimeter events, enabling interactive exploration of detector geometries and energy deposits from particle collisions.

Originally developed as CaloGeoView by Dr. Luciano Manhães de Andrade Filho, modernized by NIPSCERN for global accessibility through modern web technologies.

Launch Visualization

Technical Overview

Detector Coverage

Visualizes the complete ATLAS calorimeter system: electromagnetic (LAr) and hadronic (TileCal, HEC) sections with over 100,000 readout channels across seven detection layers

Geometry Engine

Built using ROOT geometry package with approximately 200,000 primitive shapes representing individual calorimeter cells with precise η×φ segmentation

Real-Time Performance

Processing time under 300 milliseconds for typical events with fast cell selection, rotation, zoom, and energy threshold filtering capabilities

Energy Visualization

Color-coded energy mapping: green palette for electromagnetic showers, hot palette (yellow to dark red) for hadronic deposits with user-adjustable scales

Cell-Level Analysis

Interactive cell selection reveals detailed information including energy deposits, position coordinates, PMT channels, and pulse shape data with ADC counts

Commissioning Tool

Used online in ATLAS control room for cosmic ray commissioning, detector validation, and Level-2 trigger Region of Interest visualization

Development History

CGV-WEB evolved from CaloGeoView, a ROOT-based 3D visualization tool originally developed as part of the PhD thesis of Dr. Prof. Luciano Manhães de Andrade Filho at the Federal University of Rio de Janeiro's Signal Processing Laboratory. The original CaloGeoView was designed as a Linux desktop application for visualizing CERN ATLAS calorimeter events during the detector commissioning phase with cosmic rays.

The tool played a crucial role in commissioning the ATLAS calorimeter system, enabling visual inspection of cosmic muon tracks and corresponding activated cells. This facilitated the detection of problematic channels, validation of reconstruction algorithms, and verification of calibration constants across the highly segmented detector.

NIPSCERN's modernization effort transformed CaloGeoView into a platform-independent web application, expanding accessibility for education, outreach, and scientific analysis worldwide while maintaining the sophisticated visualization capabilities of the original tool.

Key Capabilities

ATLAS Detector Scale

Visualizes events from the 42-meter long, 11-meter radius ATLAS detector at CERN's Large Hadron Collider

Multi-Layer Segmentation

Electromagnetic calorimeter: three sampling layers (Strips, Middle, Back) with granularity from 0.0031×0.0245 to 0.05×0.0245 in η×φ coordinates

Hadronic Calorimeter

TileCal barrel and extended barrels (|η| < 1.7), HEC end-caps (1.5 < |η| < 3.2) with approximately 10,000 PMT readout channels

Event Reconstruction

Displays reconstructed cosmic muon tracks, trigger tower information, and Level-2 Regions of Interest with full detector response

Data Integration

Seamless integration with ATLAS Athena reconstruction framework and ROOT data files for offline and online monitoring

Commissioning Support

Instrumental in detecting dead channels, hot cells, calibration errors, and reconstruction algorithm issues during ATLAS commissioning