Comprehensive beam jitter study for the commissioning of the intermediate matching section and drift tube linac at Ground Test Accelerator

An experiment on the Ground Test Accelerator (GTA) for the Neutral Particle Beam (NPB) at Los Alamos commissioned the intermediate matching section (IMS) and a single 3.2-MeV drift tube linac (DTL). A diagnostic platform or D-plate was used at the output of the DTL in order to measure various beam parameters. The D-plate and other diagnostic devices located in the IMS, provided measurement of the horizontal and vertical beam position, current, energy, and output phase. These instruments were installed to perform a complete beam jitter analysis based on the current beamline configuration to better understand the causes of any jitter sources as well as to prepare for the initial design of future feedback control systems. The study explored all types of jitter for various beamline configurations. Both interpulse jitter (jitter from pulse to pulse) and intrapulse jitter (jitter within each macropulse) were investigated. Spectral and statistical time analyses were used. Spectral analysis was employed to gain an understanding of the spectral contributions of various jitter sources to determine the degree of correction possible. Statistical time analysis gave a good overall representation of the jitter magnitude and allowed easy comparison of jitter for different beamline configurations, as well as an easy method for determining consistent problems