PMTs determine the original photon's X, Y location and Z value representing energy. Which three properties are represented?

PMTs determine the original photon's X, Y location and Z value representing energy. Which three properties are represented?

• A. X and Y
• B. X and Z
• C. X, Y and Z
• D. Y and Z

Answer: (C)

When a PMT-based detector captures a photon, the two coordinates in the detector plane give where the interaction happened (X and Y). The light produced by that interaction scales with how much energy the photon deposited, so the total signal provides the energy value (Z). Put together, the three properties you obtain are the position in the plane (X and Y) and the energy (Z). That’s why the best answer is X, Y and Z. The other options miss one of these essential pieces—either a spatial dimension or the energy measurement.

When a PMT-based detector captures a photon, the two coordinates in the detector plane give where the interaction happened (X and Y). The light produced by that interaction scales with how much energy the photon deposited, so the total signal provides the energy value (Z). Put together, the three properties you obtain are the position in the plane (X and Y) and the energy (Z). That’s why the best answer is X, Y and Z. The other options miss one of these essential pieces—either a spatial dimension or the energy measurement.