Difference between revisions of "20170421-JleicIonIntegration"

From CASA Wiki
Jump to: navigation, search
(New page: __NOTOC__ ==Mar 10 2017 JLEIC Ion Integration Meeting ''(and Notes)'' == ==== Bunch Formation Progress ==== * Todd has started evaluating bunch formatio...)
 
Line 1: Line 1:
 
__NOTOC__
 
__NOTOC__
−
==Mar 10 2017 [[JLEIC-Ion-Integration-Meetings|JLEIC Ion Integration Meeting]] ''(and Notes)'' ==
+
==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?)
  • Coordination with other groups
    • Beam cooling (Steve Benson et al.: Booster DC, Collider)
    • Instability/impedance (Rui Li et al.)

Reference Materials

Attendance

  • TBD
Retrieved from "https://casa.jlab.org/wiki/index.php?title=20170421-JleicIonIntegration&oldid=1769"