Rhodri Jones

1
BPM Issues in Sector 7-8

• Asynchronous Trajectory Mode
• Worked on 1st Shot
• All BPMs acquired
• BPM Problems
• BPMIV.88104 H / V flip suspected
• H pick-up on BI installation traveller should
  be V
• Fibre mix-up on 8 BPMs Q1-Q7 Left of 8
• Corrected on Saturday morning
• BPM.34R7.B2
• Horizontal plane inverted
• BPM.28R7.B2
• B1-B2 mismatch of individual button signal
• Reflectometry team?
• BPM.12R7.B2
• H / V inversion fibres crossed
• BPMWE.5L7.B2
• H polarity error (nothing visible on photos)

2
BPM Issues in Sector 7-8

• Other Suspects
• BPMW.5L7.B2
• both H V - gain/polarity? optics? ()
• BPMSX.4L8.B2
• both H V - gain/polarity? optics?
• Beam is off centre in BPMSX by 10mm (in between
  D1 D2)
• Optics
• phase advance error
• insufficient response data for further details

Courtesy of R. Steinhagen
3
BPM Issues in Sector 7-8

• Successful Tests of Synchronous Capture Mode
• BST successfully used to advance pre-pulse to 2
  turns before injection
• Data collected from a single front-end crate
• alternate BPMs from Q1L8 to Q32L8
• Conclusions
• Pre-pulse to bunch timing stable to better than
  3ns
• limited by resolution of BPM TDC
• Reproducible
• Uncorrected corrected data sets taken 2 shifts
  apart
• Will now automate this to allow quick phasing in
  of all BPMs