Undergraduate Research at Jefferson Lab

Disentangling Beam Data, Further Exploration of Multi-Pass Steering

Student: Michael Hennessey

School: McDaniel College

Mentored By: Mike Tiefenback

In the summer of 2015, we developed a computational process to compute magnetic corrections in the linear accelerators (linacs) of the Continuous Electron Beam Accelerator Facility (CEBAF) necessary to steer the five simultaneous beams of different energies near to the linear axis. This process utilizes beam position data from the linacs compiled in a vector, which is then manipulated with a matrix that represents the transport model for each beam to obtain the required corrector values. The original casting of this computation utilized corrector magnets in two directions at each correction point along the linac, and can be altered to reflect the installed correctors: one in each dimension at every other correction point. The purpose of this project is to examine and separate various dependencies and opportunities for error and misunderstanding in the process. We extract these dependencies by probing the structure and iterative stability of the computation. Our analyses determines that while the process is useful to compute corrections for the linacs, inconsistencies between corrections computed for a complete lattice vs. a lattice containing only installed correctors are observed. We propose and explore a potential cause of these inconsistencies. This result is important to the implementation of the computation, as it indicates there are not yet well understood facets of its structure. These findings will allow the accelerator scientists at Jefferson Lab to better understand the control of CEBAF and the structure of the data collected from the machine.