Speaker
Description
The 4th-generation and future light sources often require strong magnets (quadrupoles and sextupoles) with high gradients to achieve low emittance and other desired performance. These magnets especially sextupoles introduce strong nonlinear resonance driving terms (RDTs). Some low order terms could be minimized or cancelled by optimizing the sextupoles but cancelling/compensating the high order resonant driving terms remain challenging. Recently octupole gains more interests not only due to its role in adjusting the amplitude dependent tune shift (ADTS) but also its capability of compensating higher order RDTs. At the Cornell Electron Storage Ring (CESR), two octupoles have been used to adjust the ADTS to study the transverse resonance island buckets (TRIBs). It was then found that TRIBs can be used to calibrate the octupoles. Here we discuss this method in details. In addition, another beam-based calibration method is developed utilizing the turn-by-turn beam position data acquired while driving the beam with a pulsed kicker. The calibration factors obtained from both methods agree reasonably well.
Funding Agency
Work supported by National Science Foundation under awards DMR-1829070 and DMR-2342336
| Region represented | America |
|---|---|
| Paper preparation format | LaTeX |
