Difference between revisions of "20170421-JleicIonIntegration"
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* Done: | * Done: | ||
** Resolved chromatic resonance crossing problems in earlier simulations; reduced momentum spread | ** Resolved chromatic resonance crossing problems in earlier simulations; reduced momentum spread | ||
| − | ** Injection emittance growth: x5-8 | + | ** Using default working point (7.517,5.493) and bare chromaticities (-13.9,-11.5) |
| + | ** Injection emittance growth: x5-8 over hundreds of turns (~500 us) | ||
| + | ** Cooling porch emittance growth more modest (x1.5-2); no growth seen at extraction | ||
* To Do: | * To Do: | ||
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* Brahim has noted that 67+ may not be the optimal charge state for the baseline high energy linac | * Brahim has noted that 67+ may not be the optimal charge state for the baseline high energy linac | ||
* Brahim and Todd are continuing to discuss | * Brahim and Todd are continuing to discuss | ||
| + | ** Tradeoff of space charge vs stripping efficiency/pulse intensity | ||
| + | ** Todd's initial feeling is that this is a relatively flat optimization | ||
==== Other Items ==== | ==== Other Items ==== | ||
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== Reference Materials == | == Reference Materials == | ||
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* [https://www.jlab.org/conferences/jleic-spring17/ JLEIC Spring 2017 Collaboration Meeting] (Apr 3-5 2017, website) | * [https://www.jlab.org/conferences/jleic-spring17/ JLEIC Spring 2017 Collaboration Meeting] (Apr 3-5 2017, website) | ||
* [https://jlabsvn.jlab.org/svnroot/jleic/ JLEIC svn repository] | * [https://jlabsvn.jlab.org/svnroot/jleic/ JLEIC svn repository] | ||
| − | * [[ | + | * [[20170310-JleicIonIntegration | Last meeting (Mar 10 2017)]] |
== Attendance == | == Attendance == | ||
* ''TBD'' | * ''TBD'' | ||
Latest revision as of 13:05, 21 April 2017
Apr 21 2017 JLEIC Ion Integration Meeting
Report at R&D Meeting
- Todd and Ed presented slides on Ion Injector Complex/Parameter Development at the Thu Apr 20 R&D Meeting
- This summarized some recent work on Booster h=1 capture, ramp development, and Synergia space charge simulations
Booster h=1 Capture
- Done:
- 30 kV seems like the appropriate voltage for capturing initial coasting beam
- 100 ms linear RF voltage ramp is workable (see presentation); faster may be feasible
- esme simulation is relatively straightforward: RMS sigmaE/E goes from 3.1e-3 Gaussian (coasting) to 5.4e-3 parabolic (bunched)
- Have tools in place to quickly make esme "movies"
- To Do:
- Develop consensus injection energy spread (Todd/Ed/Brahim)
- Determine how fast <math>d^2B/dt^2</math> can be (Todd/Peter)
- Emails ongoing: Peter raises interesting questions about snapback and dynamic superconducting magnet effects
- Turn on injection longitudinal space charge for realistic intensities
- Compare to Synergia (Ed/Todd)
Booster Ramping
- Done:
- Tools in place and under development for generating ramp parameters
- f(RF) = 700 to 1030 kHz as input to RF design
- h=1 through Booster to extraction appears appropriate
- To Do:
- Add esme ramp generation to RampDesigner tool
- Start simulating early acceleration ramp with esme (space charge off, then on)
- Pursue cooling evaluation at 2 GeV (bunched or coasting beam? Todd/He/Ed/...)
- Evaluate addition of realistic impedances (Todd/Rui)
Booster Space Charge
- Done:
- Resolved chromatic resonance crossing problems in earlier simulations; reduced momentum spread
- Using default working point (7.517,5.493) and bare chromaticities (-13.9,-11.5)
- Injection emittance growth: x5-8 over hundreds of turns (~500 us)
- Cooling porch emittance growth more modest (x1.5-2); no growth seen at extraction
- To Do:
Linac/Booster Pb Charge State
- ANL has mostly been simulating/optimizing the low energy linac (c.f. HB'16 talk/paper by Ostroumov)
- This affects charge state and stripping optimization, but does not affect latest optimizations to handle RFQ heavy ion losses
- Heavy ion source expected to have 1-2 pi mm-mrad normalized emittance; which is it?
- Brahim has noted that 67+ may not be the optimal charge state for the baseline high energy linac
- Brahim and Todd are continuing to discuss
- Tradeoff of space charge vs stripping efficiency/pulse intensity
- Todd's initial feeling is that this is a relatively flat optimization
Other Items
- AOB
Reference Materials
- JLEIC Fall 2016 Collaboration Meeting (Oct 5-7 2016, InDiCo)
- JLEIC Spring 2017 Collaboration Meeting (Apr 3-5 2017, website)
- JLEIC svn repository
- Last meeting (Mar 10 2017)
Attendance
- TBD
