Difference between revisions of "20170421-JleicIonIntegration"
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− | == | + | ==Apr 21 2017 [[JLEIC-Ion-Integration-Meetings|JLEIC Ion Integration Meeting]] == |
+ | |||
+ | ==== Report at R&D Meeting ==== | ||
+ | * Todd and Ed presented slides on [http://casa.jlab.org/MEIC%20meeting/20170420/2017-04-20-JleicRD-IonIntegration.pptx 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 | ||
+ | ** Injection emittance growth: x5-8 with | ||
+ | * 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 | ||
+ | |||
+ | ==== Other Items ==== | ||
+ | * | ||
==== Bunch Formation Progress ==== | ==== Bunch Formation Progress ==== |
Revision as of 13:01, 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
- Injection emittance growth: x5-8 with
- 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
Other Items
Bunch Formation Progress
- Todd has started evaluating bunch formation proposals from Jiquan
- Spreadsheet and simulation (esme) progress
- Involved cross-check between spreadsheet and esme
- slides are here
- Will set up meeting to discuss RF constraints with Jiquan/Shaoheng
Beam Parameter Spreadsheet
- Todd continues to develop a draft beam parameters spreadsheet (pdf), including input parameters and derived parameters
- Have added rough start at some instability thresholds, verified longitudinal parameter calculations vs esme
- Some items (particularly space charge calculation) need to be revisited to agree with Jiquan's calculations
- Note that these are explicitly beam parameters, (mostly) not accelerator hardware parameters (e.g. lattices, instrumentation, etc)
- Will move forward with reorganizing beam/lattice parameters area in coming weeks
- Three goals:
- Ensure consistency of design beam parameters at matchpoints between JLEIC machines
- Provide input to impedance and instability calculations, and broader beam simulation effort
- Serve as a machine-by-machine beam parameter reference for the eventual CDR
R&D Items: Ion Integration
- Bunch formation (Jiquan, Todd, Randy; Ed, Vasiliy)
- See above update
- Randy is assisting Todd with esme calculations; will cross-validate with BLonD (CERN python longitudinal code)
- Booster injection (Ed)
- Ed has reviewed literature, is resurrecting Synergia work
- Update in two weeks?
- Linac (Brahim; Todd, Ed, Amy)
- Brahim is evaluating tradeoffs of H+ vs H- beam transport
- Reported at Mar 2 R&D meeting; further report at collaboration meeting
- Existing modeling is good enough to use for beam parameters for Booster injection
- Booster extraction (Ed/Todd?) / Booster to Collider (Todd, Yves?) / Collider injection (Vasiliy?)
- Bucket to bucket synchro/cogging?
- Final beam stripping
- Polarization (AGS to RHIC transfer spin design chapter)
- Coordination with other groups
- Beam cooling (Steve Benson et al.: Booster DC, Collider)
- Instability/impedance (Rui Li et al.)
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 (Feb 10 2017)
Attendance
- TBD