Fermilab, Batavia
Fermilab is jointly developing capabilities in high gradient and high Q superconducting accelerator structures based on the 1.3 GHz TESLA technology. Based on an INFN/TESLA design, a wire-position-monitor (WPM) system is integrated to monitor cavity alignment and cold mass vibrations. The system consists of a reference wire carrying a 325 MHz signal, 7 stripline pickups (per cryomodule), and read-out electronics using direct digital signal down-conversion techniques. We present technical details of the system, and preliminary results on resolution and stability measured at a mock-up test stand.
Fermilab, Batavia
A system was developed for bunch-by-bunch detection of transverse proton and antiproton coherent oscillations based on the signal from a single beam-position monitor (BPM) located in a region of the ring with large amplitude functions. The signal is digitized over a large number of turns and Fourier-analyzed offline with a dedicated algorithm. To enhance the signal, the beam is excited with band-limited noise for about one second, and this was shown not to significantly affect the circulating beams even at high luminosity. The system is used to measure betatron tunes of individual bunches and to study beam-beam effects. In particular, it is one of the main diagnostic tools in an ongoing study of nonlinear beam-beam compensation studies with Gaussian electron lenses. We present the design and operation of this tool, together with results obtained with proton and antiproton bunches.
