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...)
 
 
(One intermediate revision by the same user not shown)
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]] ==
  
−
==== Bunch Formation Progress ====
+
==== Report at R&D Meeting ====
−
* Todd has started evaluating bunch formation proposals from Jiquan
+
* 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
−
* Spreadsheet and simulation (esme) progress
+
* This summarized some recent work on Booster h=1 capture, ramp development, and Synergia space charge simulations
−
* Involved cross-check between spreadsheet and esme
+
−
* [http://www.toddsatogata.net/JLEIC/2017-03-10-JleicBunchFormation.pptx slides are here]
+
−
* Will set up meeting to discuss RF constraints with Jiquan/Shaoheng
+
  
−
==== Beam Parameter Spreadsheet ====
+
==== Booster h=1 Capture ====
−
* Todd continues to develop a [http://www.toddsatogata.net/JLEIC/JLEICBeamParameters.xlsx draft beam parameters spreadsheet] ([http://www.toddsatogata.net/JLEIC/JLEICBeamParameters.pdf pdf]), including input parameters and derived parameters
+
* Done:
−
** Have added rough start at some instability thresholds, verified longitudinal parameter calculations vs esme
+
** 30 kV seems like the appropriate voltage for capturing initial coasting beam
−
** Some items (particularly space charge calculation) need to be revisited to agree with Jiquan's calculations
+
** 100 ms linear RF voltage ramp is workable (see presentation); faster may be feasible
−
** Note that these are explicitly '''beam''' parameters, (mostly) not accelerator hardware parameters (e.g. lattices, instrumentation, etc)
+
** esme simulation is relatively straightforward: RMS sigmaE/E goes from 3.1e-3 Gaussian (coasting) to 5.4e-3 parabolic (bunched)
−
** Will move forward with reorganizing beam/lattice parameters area in coming weeks
+
** Have tools in place to quickly make esme "movies"
−
* Three goals:
+
* To Do:
−
** Ensure consistency of design beam parameters at matchpoints between JLEIC machines
+
** Develop consensus injection energy spread (Todd/Ed/Brahim)
−
** Provide input to impedance and instability calculations, and broader beam simulation effort
+
** Determine how fast <math>d^2B/dt^2</math> can be (Todd/Peter)
−
** Serve as a machine-by-machine beam parameter reference for the eventual CDR
+
*** 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)
  
−
==== R&D Items: Ion Integration ====
+
==== Booster Ramping ====
−
* Bunch formation (Jiquan, Todd, Randy; Ed, Vasiliy)
+
* Done:
−
** See above update
+
** Tools in place and under development for generating ramp parameters
−
** Randy is assisting Todd with esme calculations; will cross-validate with BLonD (CERN python longitudinal code)
+
** f(RF) = 700 to 1030 kHz as input to RF design
−
* Booster injection (Ed)
+
** h=1 through Booster to extraction appears appropriate
−
** Ed has reviewed literature, is resurrecting Synergia work
+
* To Do:
−
** Update in two weeks?
+
** Add esme ramp generation to RampDesigner tool
−
* Linac (Brahim; Todd, Ed, Amy)
+
** Start simulating early acceleration ramp with esme (space charge off, then on)
−
** Brahim is evaluating tradeoffs of H+ vs H- beam transport
+
** Pursue cooling evaluation at 2 GeV (bunched or coasting beam? Todd/He/Ed/...)
−
** Reported at Mar 2 R&D meeting; further report at collaboration meeting
+
** Evaluate addition of realistic impedances (Todd/Rui)
−
** 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?)
+
==== Booster Space Charge ====
−
** Bucket to bucket synchro/cogging?
+
* Done:
−
** Final beam stripping
+
** Resolved chromatic resonance crossing problems in earlier simulations; reduced momentum spread
−
** Polarization ([http://www.agsrhichome.bnl.gov/RHIC/Spin/design/chap3.pdf AGS to RHIC transfer spin design chapter])
+
** Using default working point (7.517,5.493) and bare chromaticities (-13.9,-11.5)
−
* Coordination with other groups
+
** Injection emittance growth: x5-8 over hundreds of turns (~500 us)
−
** Beam cooling (Steve Benson et al.: Booster DC, Collider)
+
** Cooling porch emittance growth more modest (x1.5-2); no growth seen at extraction
−
** Instability/impedance (Rui Li et al.)
+
* 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 ==
 
== Reference Materials ==
Line 43: Line 54:
 
* [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]
−
* [[20170210-JleicIonIntegration | Last meeting (Feb 10 2017)]]
+
* [[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

Attendance

  • TBD
Retrieved from "https://casa.jlab.org/wiki/index.php?title=20170421-JleicIonIntegration&oldid=1770"