Possible Problems in Phase A.7:

1. The BRAN luminosity monitors were designed for top energy ( 7 TeV) collisions and high luminosity runs:

   • The angular coverage is insufficient for the larger 450 GeV beams. Statistics and signal to noise ratios will be marginal. Information from the experiments will be required to confirm we have collisions.

    

2. BRANs in IP1 and IP5 might not work for the 450 GeV run (noise as high as signal)

    

3. We expect small but non-negligible hysteresis effects from the orbit correctors used for the separation scans at 450 GeV. These should be taken into account to minimize the separation between the two beams.

    

4. Poor intensity lifetime:

   • Check/optimize working point

5. Emittance growth:

   • Check nothing kicks the beam;

   • Vibration (low frequency FFT);

   • Minimize RF noise

6. Background always raising:

   • Check orbit, aperture, vacuum

7. Poor luminosity:

   • Re-optimize-check/adjust separation