Emittance measurements at the Bates linac

An emittance measuring system has been installed at the Bates Linear Accelerator Center. The system consists of three wire scanners used to measure the electron beam profile, and a microcomputer for data acquisition and processing. The scanner measures the horizontal and vertical beam size with a possible resolution of 25 μm. The horizontal and vertical beam phase spaces can then be determined. Results of measurements are presented. Calculations relating the theoretical accuracy of the emittance measurements to the distance separating the scanners and to the beam waist´s location and size are also presented. Another technique for measuring emittance has also been used. This technique involves using a wire scanner to measure the beam size at a fixed location, as a function of the strength of an upstream quadrupole