Talk:Specification for 12 GeV electron beam and associated instrumentation

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Changes on May 31, 2008 - Richard Jones

I made the following changes today, together with the revisions being made to the Hall D - Accelerator Interface Document.

  1. Change the maximum electron beam energy spread from 0.5% to 0.1% (year 2 and following). The expected energy spread of the 12 GeV beam in the tagger hall is still a factor of 5 better than the new number, so this doesn't drive anything in the design. The change is made to reflect the requirements for Primex in Hall D.
  2. Change the bandwidth of the active steering feedback loop controlled by the active collimator that keeps the beam centered on the collimator. The prototype active collimator is capable of providing a correction signal with a bandwidth up to 1kHz at beam currents of 300nA or above, so this change does not require any design changes in the collimator system. This figure may require further refinement after we hear from the accelerator designers whether a 1KHz feedback loop controlling the steering dipoles on the electron beam line is feasible or not.