Search Results (4 total)

The transverse turn-by-turn evolution of a bunch slice after an impulse kick is examined considering chromatic and impedance effects. It is found that by fitting the envelope of the beam slice motion to simulated data the strength of the resistive wall wakefield can be determined.

We will explore a method for measuring chromaticity by continuously kicking the beam transversely. This is called the continuous head-tail method for measuring chromaticity. The complete analytic approximation in terms of trigonometric functions is derived for zero transverse emittance beam. A simple formula for calculating chromaticity from experimental data is also shown. Finally, the theory is compared with experimental data.

A spin matching method to cure intrinsic coupled spin resonances in the AGS is proposed and explored using an extension of the existing DEPOL program algorithm. The extension of DEPOL to handle linear coupling in the polarized beam acceleration is documented. Data collected from recent polarized proton experiments in the AGS are compared with the predictions derived from the extended DEPOL program.

Higher-order and coupled snake resonances were observed during the 2002 polarized proton run in RHIC. Strong depolarization was observed when the fractional part of the vertical betatron tune approached 1/4, and when the fractional part of the horizontal tune approached 3/14. Because of the closed orbit error, each snake resonance splits into two. From the width of the observed snake resonances, we can derive the strength of the imperfection spin resonance. Our results appear consistent with the measured closed orbit error.