Difference between revisions of "UITF Notes"

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== For future study ==
 
== For future study ==
 
* Provided the BPMs work at all, we can use the 701 and 702 BPMs to better measure the momentum jitter. The CW waveforms give time-domain data in 900-microsecond-long windows with 16384 samples each, i.e., ~ 18 kHz sampling rate, 9 kHz analog bandwidth. More than enough to see all peaks, maybe even a little much to resolve them well. The only problem is, we can only run 100 nanoamps CW into that line. See if that's enough to see anything.
 
* Provided the BPMs work at all, we can use the 701 and 702 BPMs to better measure the momentum jitter. The CW waveforms give time-domain data in 900-microsecond-long windows with 16384 samples each, i.e., ~ 18 kHz sampling rate, 9 kHz analog bandwidth. More than enough to see all peaks, maybe even a little much to resolve them well. The only problem is, we can only run 100 nanoamps CW into that line. See if that's enough to see anything.
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 +
== Take home ==
 +
* Current picture of ITVM703 to make sure width/height is still what it was
 +
* 703 harp file, e.g., /cs/data/harpData/IHAM703/IHAM703.10262021_18:....
 +
* using 703 harp, measure momentum spread vs. something interesting, e.g., buncher amplitude

Revision as of 11:00, 29 November 2021

Random

  • Harp axis calibration does not matter: It only changes the measured emittance but not alpha/beta, and its effect does not depend on the quad in use.
  • Adding reasonable quadrupole moments to correctors is not enough to explain the inconsistency. It would need an extra quad with K1 ~ 5.
  • At dp/p = 1e-3 (which is higher than what we observe unless the measurement is flawed), seeing significant inconsistencies in the quad scans needs a dispersion of many cm. In y, the only dispersion in this part of the lattice should come from the earth's field; this gives about 8 mm at the harp, much too low to see anything.

For future study

  • Provided the BPMs work at all, we can use the 701 and 702 BPMs to better measure the momentum jitter. The CW waveforms give time-domain data in 900-microsecond-long windows with 16384 samples each, i.e., ~ 18 kHz sampling rate, 9 kHz analog bandwidth. More than enough to see all peaks, maybe even a little much to resolve them well. The only problem is, we can only run 100 nanoamps CW into that line. See if that's enough to see anything.

Take home

  • Current picture of ITVM703 to make sure width/height is still what it was
  • 703 harp file, e.g., /cs/data/harpData/IHAM703/IHAM703.10262021_18:....
  • using 703 harp, measure momentum spread vs. something interesting, e.g., buncher amplitude