The Top Surface of the Detector (IMAGE) California Institute of Technology Caption The NOvA detector measures 50 feet by 50 feet by 200 feet, and the top surface of the detector as shown here is covered with readout and monitoring systems. Each gold-colored box in the image contains a photodiode array, cooling components, and associated electronics to detect light from 32 of the 344,000 cells that make up the detector. Credit Reidar Hahn/Fermilab Usage Restrictions With credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.