UBC Theses and Dissertations
Preparation for commissioning the triumf magnet Friesen, Errol Lane
This report examines some of the work that has been done in preparing for the shimming and subsequent trimming involved in commissioning the TRIUMF magnet. A series of experiments was done to determine the exact changes in the average field and in the focusing properties resulting when different sizes of shims were placed at various positions on the pole piece. The components of the focusing changes were broken down, using a linear approximation, so as to examine the factors causing them. In order to facilitate shimming, a computer program was developed which used this data to predict the amount of steel to be placed at each position on the magnet pole piece in order to give the best improvement to both the average field and the focusing. This program was tested on a 10:1 model and found to reduce errors in the average field to 20% of the original after two iterations, at the same time improving the focusing, although it tended to break down at significant spiral angels when large corrections were required. The cause for this breakdown was indicated and an improvement procedure recommended. Finally, a series of experiments, using a computer program, were made to determine the trim coil capacities that would be needed. It was found that these capacities were significantly lower than had previously been expected.
Item Citations and Data