Recycler BPM Requirements Review

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Recycler BPM Requirements Review 

• Mike Martens (Chair), Keith Gollwitzer, Dave
  McGinnis, Dave Capista, Mike Syphers,
• Lewis Emory, Valeri Lebedev
• November 25, 2002

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Charge to the Committee
1) Are the proposed set of BPM measurement
capabilities complete? Are they adequate to
ensure the effective commissioning and operation
of the Recycler through Run II? 2) Prioritize
these measurement capabilities. Which are most
important and which are least important, in your
view?
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Presentations to the Committee
Shekar Mishra presented a schedule from the MI
department perspective. Brajesh Choudhary
presented the requirements for the Recycler BPMs
in a talk Requirements for the Recycler Ring
Associated Transfer Lines BPMs A round table
discussion followed the presentation where
questions were asked and points of view voiced.
The intention of the charge was to ignore
technical and cost issues, but these were
discussed to some extent. The committee members
met to discuss our findings and recommendations.
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Schedule from the MI Perspective.

• Recycler is working to about 85.
• There are still several issues which needs
  resolving to improve its performance.
• Instrumentation including BPM is key to this
  improvement.
• We need a working, stable BPM system at least one
  month before the Summer Shutdown.

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Committee Recommendations

• Provide a prioritized list of measurements that
  are desired. (i.e. Closed Orbit Measurement with
  2.5 MHz protons, one-bump measurements with 2.5
  MHz protons, etc.)
• Some of the specifications need a less ambiguous
  definitions. For instance, what is meant by 5
  linearity.
• Need a better justification for Flash orbits
  since this heavily influences the choice of BPM
  hardware.

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Committee Recommendations (continued)

• Calibration and Test specifications should be
  defined by RR group.
• The need for TBT capability should be
  re-examined. Can lattice measurements be made
  equally well with other methods?
• Specifications for the transfer line BPMs was not
  discussed.

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Prioritized List of Measurements.
Helpful to have a list of BPM measurements
according to function, and listed by priority.
Each measurement should specify type of beam and
accuracy of BPMs. This was partly specified but a
different format may be useful. We note that
most of the tune-up and commissioning is likely
to be with proton beam. This will make it easier
to specify the intensity of the beam for
measurements with protons. We make a suggested
list of priorities. We recognize that the
necessity for FLASH data determines the ordering
of the list. (See other slides.)
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Prioritized List of Measurements.

• For a prioritized list of BPM measurements we
  suggest something like
• Closed Orbit Measurement. With Protons at 2.5
  MHz. Specify beam intensity and position
  accuracy.
• Lattice Measurements. One-bump method with 2.5
  MHz protons. What accuracy in position is needed
  to get 5-10 accuracy in lattice measurements.
• Closed Orbit Verification. With antiproton in
  barrier bucket. Purpose is to verify orbit has
  not drifted.
• Injection Closure. With 2.5 MHz pbars. Use BLT
  method.
• Injection Closure. With 2.5 MHz protons. Use
  FLASH frame.
• Continuous Mode. With pbars in barrier bucket?
• TBT lattice measurements. With 2.5 MHz protons.

?
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Better Definitions of Specifications.

• Some of the linearity and accuracy specifications
  need a better definition.
• For instance, ? 1.00 mm ? 5 of actual position,
  is ambiguous.
• We suggest specifying
• acceptable error in offset,
• acceptable error in gain,
• acceptable non-linearity.
• A formula would be helpful.

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Need for FLASH frame?
The need for FLASH frame capability needs better
justification. Certainly it would be helpful to
have, however this choice heavily influences the
type of BPM hardware (between narrow band and
TBT) and will likely have a big influence on
cost. We recognize the usefulness of first and
last turn flash, but we question whether it is
strictly necessary for operations. How much do
things drift in recycler? Isnt most of the
commissioning already done?
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Specify Calibration
The calibration specifications should be better
defined. The recycler group should decide what
type of diagnostics are necessary. We highly
recommend a test for electrical offset. A test
for electrical gain may also be useful.
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Need for TBT capability?
The need for TBT capability needs better
justification. It was not clear to the
committee. Whether TBT capablity is necessary.
The stated use for TBT was lattice function
measurements. However, we ask if other methods
the one bump method, for instance might not
give just as accurate results. This choice is
important since it heavily influences the choice
of BPM hardware.
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Specifications of Transfer Line BPMs
We do not have a list of specifications for the
transfer line BPMs. A set of specifications
should be developed.