Partial Discharge Effects on Beam Dynamics
This project is part of the G-2 experiment*. In the G-2 ring, charges can build up on certain surfaces, then after enough build-up, a spark is created. However, in addition to large discharges, there are also smaller partial discharges, sometimes referred to as ‘sparklets’.
(The note and presentation below were written for the members of the G-2 experiment. Therefore, there is little background in the note and jargon may be used.)
GitHub code: https://github.com/EmptyBucket9000/BNL_Sparklets
Technical note: effect_of_partial_discharge_on_beam_dynamics.pdf
Power point presentation: effect_of_partial_discharge_on_beam_dynamics_presentation.pdf
The sparklets would partially discharge the quadrupole electrodes, causing a change in electric field strength of about 2%. The change itself would occur over approximately 156 ns and the recovery was exponential with a time constant of about 5 micro seconds. The electrodes are not continuous around the ring, the are four long quadrupoles and four short quadrupoles.
My task with this project was to determine, through tracking in Python, what the effect of these sparklets was on the y, y-prime phase-space of the muons. Both a drop and a kick in the electric field was tested.
The approach was straight-forward. Track the muons assuming constant momentum in the z-direction (forward around the ring) and in the x-direction (assuming local cartesian coordinates with the muon always at the origin). The muon was tracked with various possible values of y and y-prime, allowed by the phase-space.
I was an intern working with William M. Morse at Brookhaven National Lab (BNL). More information on this experiment can be found at the Fermilab and BNLÂ websites.