Proton beam lifetime at 150 GeV, chromaticity and tune scans, aperture, scraping 12/03-04/02

During a dedicated machine study on December 3-4, 2002, we measured the chromaticities, the proton beam lifetime and loss rates at 150 GeV on the central orbit, the proton helix, and the pbar helix. On the proton helix we dry-fired rhe pbar injection to observe a possible impact of injection kickers and wire scans. We next studied the dependence of the lifetime on tunes and on chromaticity, for both helices. At this occasion, we found an instability threshold for the pbar helix. We reduced the vertical aperture by moving collimator F49VCP closer to the beam, and measured the effect on the loss rate. We lastly removed a part of the proton beam by this collimator to get an emittance estimate independent of the flying wires.