Difference between revisions of "Model March 08 2016"

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m (New page: Previous action items (see march 1st minutes ) == FOPT dispersion measurement versus 30Hz measurement == An ATLIS has been created to compare FOPT versus the 30H...)
 
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Previous action items ([[Model_March_1st_2016|see march 1st minutes]] )
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Previous action items ([[Model_March_01_2016|see march 1st minutes]] )
  
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== FOPT dispersion measurement versus 30Hz measurement ==
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* ATLIS created to study FOPT versus 30 Hz.
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* Future release of eDT will set the separator angle.
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* eDT will load setpoint2 for the MCP1P01 magnet to the actual BDL needed for the chicane
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* qsUtility was released with the sqrt(2.0) bug fix as well as a number of other improvements.
  
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An ATLIS has been created to compare FOPT versus the 30Hz measurement.
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== girders in the model ==
  
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== Separator setup ==
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In the real machine, quadrupoles are arranged on girders  (With a few exceptions) featuring a specific
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a future release of eDT will set the angle
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layout of diagnostics and correctors. There is a finite type of girders. We discussed whether one should capture
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this in the model.  The first step would be to write scripts to check that the element placement is indeed accurately captured.
  
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== 2R optics errors ==
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== diagnostic and corrector lengths ==
  
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There is still an optics error in the 2R region leading us to adjust 2R02 by 30 % or so. Quadrupoles in this region were checked multiple times. However this was done with a gaussmeter probe and may not have been sensitive enough to detect the error if it is due to a miswiring of the coils. A similar issue for the BT03 quadrupole was also missed with the probe and yet discovered when physically checking the connections at the patch panel.
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Currently we captured the diagnostics and correctors as zero length elements. For correctors, this location in the center of it, for the bpms,
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the location in that of the antennas (3 inches from end of can).
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There are benefits to actually model the true length of all of these elements. This is a significant undertaking and likely will have to be done
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via scripting to post process the existing decks. It was felt that while it is useful, it is a medium to long term project.
  
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Previous beam based differential orbit measurement in this region did not result in a clear outlier. We could not attribute the error to a single qua, hence the suspicion it must be miswiring.
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== dipole lengths ==
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During the summer down, I will write an ATLIS to ask for a systematic check of the connections, using the same technique M. Tiefenback used for the BT03 quad.
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== Compton dipole setup ==
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the current Optics decks have the compton dipole unpowered. It was done on purpose to avoid having the dipole loaded and turned on when we actually want to go straight-thru. We are considering to instead have the decks reflect the beam path going thru the chicane and have eDT load that BDL to setpoint 1 of the dipole.
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Since eDT does not turn magnets off, it will still be setup in straight-thru but we will have the needed BDL in setpoint 1 when wanting to setup through the chicane.
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Setpoint 2 can be used as the zero field setpoint.  We will check that this convention adheres to what is already the case elsewhere in the machine.
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== qsUtility ==
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Scheduled to be released with the sqrt(2.0) bug fix as well as a number of other improvements.
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== Fast feedback in Hall A ==
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It is likely underpowered for 11 GeV. The coils were not upgraded to run at twice the amperage when migrating from 6 to 12 GeV.
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The 2L26 RF vernier is tripping the C100 zone as well. Concerned parties have been contacted to assess and hopefully fix it.
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I will (Yves) see if there is any benefit in moving some of the FFB correctors to a better location.
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Revision as of 18:33, 12 March 2016

Previous action items (see march 1st minutes )

  • ATLIS created to study FOPT versus 30 Hz.
  • Future release of eDT will set the separator angle.
  • eDT will load setpoint2 for the MCP1P01 magnet to the actual BDL needed for the chicane
  • qsUtility was released with the sqrt(2.0) bug fix as well as a number of other improvements.

girders in the model

In the real machine, quadrupoles are arranged on girders (With a few exceptions) featuring a specific 

layout of diagnostics and correctors. There is a finite type of girders. We discussed whether one should capture
this in the model.  The first step would be to write scripts to check that the element placement is indeed accurately captured.

diagnostic and corrector lengths

Currently we captured the diagnostics and correctors as zero length elements. For correctors, this location in the center of it, for the bpms, the location in that of the antennas (3 inches from end of can). There are benefits to actually model the true length of all of these elements. This is a significant undertaking and likely will have to be done 

via scripting to post process the existing decks. It was felt that while it is useful, it is a medium to long term project.

dipole lengths

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