A Portable Gamma-Ray Spectrometer

The spectrometer comprises a single-channel scanning pulse-height analyzer, high-voltage supply, photo. multiplier tube and sodium iodide crystals. The circuits are transistorized and driven from rechargeable batteries. The analyzer contains a linear amplifier, window discriminator, count rate circuit and miniature recorder. The recorder and window discriminator are driven synchronously to display a spectrum in twelve minutes. The circuits, application and performance are discussed.