Design and Construction of a stretched wire test bench to characterize Beam Position Monitor for the High Energy Storage Ring

摘要

Accelerator physics is a branch of applied physics, which deals with design, construction and operation of particle accelerators. In today’s world, their uses cover varied fields such as study structures in chemistry and biology or to perform sensitive trace element analysis. Moreover, accelerators have become entrenched as the key tools in the study of subatomic particles. Whether the application is scientific, industrial or medical, beam diagnostics is an essential constituent of an accelerator. This deals with the design and operation of instrumentation devices for monitoring the beam properties. Without adequate beam diagnostics, achievement of beam for physics use would be impossible as the beam is sensitive to imperfections of the accelerator. A beam position monitor (BPM) is one such beam diagnostic device. This project deals with diagonally cut capacitive pickup as this design was chosen for High Energy Storage Ring (HESR) due to its high linear response and high sensitivity. Prior to beam operation, it is necessary to characterize the BPM which involves: establishing a relationship between the measured beam position and the actual one. This is achieved with the help of a standalone test bench using stretched wire method. Therefore, a test bench is designed and constructed to calibrate the BPM. Followed by which, a software/application is developed which can perform automated linearity tests. Linearity tests are carried out for two test configurations namely high particle intensity i.e. 1010 particles and low particle intensity i.e. 1E8 particles. For both test configurations, positional accuracy could be measured successfully within the requirements of the project which is 100 μm for 1E10 particles and 1 mm for 1E8 particles, for turn by turn detection. However, there is a considerable influence of noise signals on the uncertainties of the measurement itself. Their effects could be minimized by averaging over a considerable amount of revolutions. Moreover, for approving the series production of HESR BPMs, single turn detection measurement will be carried out on the test bench. This mode of operation aims for beam injection optimization where a resolution of 1 mm is expected with particle intensities of 1E7 and 1E8.