Muon Radiography in Chephren Pyramid

The first attempt to create an image with muons was made around 1968 by Luis Alvarez's team in the Pyramid of Chephren, the second largest pyramid in Giza. When compared to the interior complexity of the other two pyramids of Giza, the pyramid of Chephren has a very simple internal structure, only with a single chamber. It was with this in mind that Alvarez decided to probe the interior of this pyramid in search of unknown chambers and for this he took into account the absorption of the muons by the crossed material and that would show if there was some empty space in the interior if in some direction the muon flux was higher than expected.

The detection equipment, consisting of five planes of spark chambers triggered by scintillation counters, was placed inside the only known Chamber of Belzoni, located at the base and almost at the center of the pyramid.

The exposure area covered all directions at ±45° from the vertical and the clear detection of the edges of the pyramid as well as the cap on top of the pyramid, showed that the technique worked and was reliable. Unfortunately, no additional structures were found.

Publication:

"Search for Hidden Chambers in the Pyramids" (Alvarez et al., 1970)