# 2019-01-18-LeadershipReports

Jan 7-Jan 18

**Director - Todd Satogata**

Previous two weeks (May 14-May 25) - JLEIC: pCDR writing, template, EIC lunch, impedance and R&D meetings - JLEIC: P&C Meeting (May 21) - ODU: Continue Randy advising, presentation to committee (May 24) - ADMIN: Leadership/group meetings, staffing input and planning - ADMIN: Prepare for summer student arrivals - IPAC18: Complete proceedings, light peer review, delegate survey - OPS: BTeam meetings, Hall D optics analysis - VACATION: Half-days May 22-25 (Leah hospital visit for broken hip) Next two weeks (May 28-June 8) - JLEIC: pCDR writing, template, EIC lunch, impedance and R&D meetings - JLEIC: Further organize ICFA beam dynamics newsletter input - ADMIN: Summer student setting in, work planning - ADMIN: Leadership/group meetings, staffing input and planning - ADMIN: CASA group meeting (Jun 6) - ODU: Continue Randy advising, dissertation draft finalization - IPAC18: Finalize proceedings, delegate survey report

Alex Bogacz

Previous two weeks (May 14-May 25) - IPAC18: Light peer review paper review, QA - ADMIN: Phys Rev paper review - ADMIN: Review five STFC grant proposals (for UK) Next two weeks (May 28-June 8) - ADMIN: Summer student lecture prep, lecture (June 5) - IPAC18: Light peer review paper final checks and delivery - LHEC: Work on paper on LHeC ERL scaling

Rui Li

Previous two weeks (May 14-May 25) - JLEIC: Impedance meeting (May 14) - JLEIC: finish IPAC paper on longitudinal coupled bunch instability - VACATION: (May 17-18, May 25 half-day) - JLEIC: Discuss HOM ion ring damping with Frank Marhauser - JLEIC: Work on pCDR writeup Next two weeks (May 28-June 8) - JLEIC: Work on pCDR writeup - JLEIC: Calculate ion coupled bunch instability growth rates with new HOM design from Marhauser - JLEIC: Work on ICFA newsletter section on beam dynamics in JLEIC rings

Ed Nissen

Previous two weeks (May 14-May 25) - JLEIC: Continue draft writing for pCDR - JLEIC: Continue booster nonlinear optimization work - JLEIC: Start Booster acceleration simulations Next two weeks (May 28-June 8) - ADMIN: Summer student setting in, work planning - JLEIC: Continue Booster acceleration simulations - JLEIC: Continue booster nonlinear optimization work - JLEIC: Finish draft writing for pCDR

Chris Tennant

Previous two weeks (May 14-May 25) - PERLE: Continued CSR analysis, initial S2E PERLE bunch tracking - JLEIC: gather information/text/figures for pCDR draft - JLEIC: Troubleshoot multiple versions of Cheng-Ying Vlasov Solver Next two weeks (May 28-June 8) - JLEIC: investigate effect of using 2x longer bunch in CCR - JLEIC: begin pushing a realistic (via Fay) bunch through ERL driver of CCR and assess performance (i.e. will it make it around the first arc, let alone make it to the CCR?) - JLEIC: further pCDR prep/writing

**Accelerator R & D - Y. Zhang**

Fanglei Lin

Previous two weeks (Dec 28 - Jan 4) - Worked on the storage ring cooler project - Worked on studying nonlinear beam dynamics in the electron collider ring - Miscellaneous: attended the uses of UITF meeting, attended the - JLEIC R&D meeting, attended the Innovative HE Cooling Project Status meeting, attended the Storage Ring Cooler meeting, attended JLEIC general meeting Next two weeks (Jan 7 - Jan 18) - Work on the storage ring cooler project - Revisit the electron collider ring design with PEP-II magnets - Electron spin study using BMAD

Vasiliy Morozov

Previous two weeks (Dec 28 - Jan 4) - Spin transparency experiment: calculation of the spin response function of RHIC, spin tracking simulation setup - IR design: optimization for 200 GeV/c ion momentum - SBIR: preparation of an LoI for space charge mitigation Next two weeks (Jan 7 - Jan 18) - Preparation of the DoE quarterly report - Work on spin transparency experiment - Continue IR design optimization, design of a correction system - Analysis of crab crossing experimental data

Amy Sy

Previous two weeks (Dec 28 - Jan 4) - Preparing for the DOE/SC Independent Project Review of DUNE/LBNF at Fermilab; getting familiar with the project and current status. Participated in a conference call with LBNF Beamline team members in advance of the review. - Studying TRACK code and input files for the ion linac in advance of meeting with ANL collaborators to discuss current and future ion linac work. - Paper studies on intrabeam stripping of H- beam in superconducting linacs, as at LEAR and SNS, to evaluate the impact at JLEIC. Next two weeks:

-Participating in the DOE/SC IPR of DUNE/LBNF as a member

of the Beamline review team.

-Meeting with Brahim Mustapha and Zack Conway at ANL to

discuss the ion linac.

-Follow-on activities related to both trips.

Guohui Wei

- On Leave

Yuhong Zhang

- Explored RHIC magnets for the JLEIC ion collider ring
- Organized study on high-energy JLEIC, worked on several issues (ion injector, baseline, luminosity estimate)
- Worked with Fanglei on figure-8 footprint
- Attended several meetings to discuss preCDR
- Organized writing a contribution to ICFA Beam Dynamics newsletter
- Continued to write preCDR

**Computational Physics - Y. Roblin**

Kirsten Deitrick

- Last two weeks:
- Magnetized beam (LERF PoP):

- -re-phasing for FEL boosters after correcting buncher setting
- -discovering the correct off-crest phase for booster cavities
- -zeroing after FEL booster
- -discontinuing work on UITF; since it's being installed in CEBAF, it can't be used in the LERF PoP

- Straight Merger at CBETA:

- -beginning data analysis, getting GPT decks set up

- CSR:

- -continue working on KEK CSR tech note (minimal)

- eCloud:

- -pull ion beam sizes/parameters from presentations; feed into PyECLOUD
- -email CERN questions related to PyECLOUD results
- -email people (J.L. Vay, M. Furman, Amundson, Crittenden) about codes (WARP+POSINST, POSINST, different POSINST, ECLOUD)

- Impedance:

- -general meeting
- -smaller meeting specific to pre-CDR documentation
- -schedule next impedance meeting (June 25th)

- Meetings:

- -Impedance (general)
- -Impedance (pre-CDR)
- -CASA
- -Cooler x2 (verbal preliminary on Straight Merger at CBeta results, -)
- -CBETA weekly meeting x2
- -JLEIC x2 (verbal preliminary on Straight Merger at CBeta results, -)

- Misc:

- -Open House training
- -paper maintenance (finding new, organizing all)
- -helping Sajini with automation and space charge settings for ASTRA (Magnetized GTS)

- Next two weeks:
- Magnetized beam (LERF PoP):

- -evaluate skew quad position/strength on correcting booster asymmetries
- -start scan of charge/length/size

- Straight Merger at CBETA:

- -continue data analysis
- -begin rough simulations (actual simulations, if I can get the field map from George Biallas)

- CSR:

- -continue working on KEK CSR tech note (minimal)

- eCloud:

- -check with Vasiliy about other beam sizes / magnet strengths (outside of arc cell)
- -run cases with variations
- -start looking at instability thresholds?

- Meetings:

- -CASA
- -Cooler
- -JLEIC (maybe)

Yves Roblin:

- CEBAF:
- -chicane remodel
- -BTEAM
- -autosteer specs
- -spin calculations for fall2019, writing document for new spin tool

hc: 10573.4 MeV/c hb : 10575.8 MeV/c ha: 2218.39 MeV/c

- -note on ced2elegant floor calculation
- -estimates /simulations for 2R coupling
- -optics cleanup, CED bug squishing
- -preparation for half energy (SL off ) run for Hall A experiment , ARC1/ARC2/1C/3C strings cross-calibrations
- -ELEGANT update on ops to version 34.0 (Anthony did the update, I did the checking)

- JLEIC:
- -starting pulling together stuff for the pCDR beam-beam

- OTHER:
- -comp. phys. journal review, Nim A review.

Dennis Turner

- CEBAF:
- -CED2ELEGANT. Fixed a bug where termination points in the Hall D proper would lead to incorrect lattices. Tracked down to a bug in the CED API.
- -CED2ELEGANT. Fixed a bug where the extraction magnets MYA's would appear in recirculating lattices. Tracked down to a bug in the ZONE definitions in the CED.
- -AutoSteer. Started working on AutoSteer from the prototypes and notes From Y. Roblin
- -CED2ELEGANT. Adding support for generating the starting floor coordinates and angles in the generated command files

He Zhang

- Fast multipole method. The paper on Traceless Cartesian Tensor FMM for Coulomb Kernel was finally accepted. Now the paper is in pressing. An online version is available here:

https://www.sciencedirect.com/science/article/pii/S0021999118303280?via%3Dihub A parser was added to the kernel-independent FMM code. Now the code can read a kernel from a text file and perform the calculation without recompiling. Computation time is slightly increased but acceptable.

- I started to write the paper on the kernel-independent FMM based on the Cartesian tensor and Differential Algebra. Some data was generated. However, I noticed that the efficiency is not as good as expected, although DA package has been revised for better performance. After profiling the program again, it is identified the bottle neck is the Multipole-to-Particle (M2P) operator and the Particle-to-Local (P2L) operator for ill-separated boxes. Usually the dominating operator is Multiple-to-Local (P2L). But in this case, the M2P and P2L operators includes many DA calculation for high order derivatives of the kernel function and the DA calculation is time consuming, these two operators cost much more time than the M2P operator. Possible solutions are (1) use single level FMM, which does not need M2P and P2L operators, instead of multi-level FMM; (2) use some DA approximation around the box center for the high order gradient calculation; and (3) further improve DA efficiency. To test solution (1), I revised the FMM framework so that a full tree of boxes for a given level can be generated. For a uniform distribution, a single level FMM is about 20 times faster than a multi-level FMM. This confirms that the computation bottle neck is due to the M2P and P2L operator. But the efficiency of a single-level FMM reduces very fast when the particle distribution deviates from the uniform distribution. Solution (2) will bring new errors. It will need testing to see how much the error will be increased and how much the efficiency can be improved. As to solution (3), the DA calculation efficiency can be improved by faster indexing of the DA element. But I think what we can gain is limited.
- To demonstrate the kernel-independent property, we should present the calculation results for various kernels. For 2D solutions of the modified Laplace equation, the modified Stokes equation, and the modified Navier equation, one needs to calculate the first and the second kind modified Bessel functions K0 and K1. The current DA package cannot do this calculation. After some investigation, I found K0 and K1 can be calculated by the rational approximation method (Pavel Holoborodko), which is implemented in the boost library. The method should be adaptive to DA calculations.

pCDR writing

- A draft including the following topics has been finished: Multi-Stage Cooling Scheme, Simulation Program (JSEPC) Development, DC Cooling in the Collider, Bunched Beam Cooling in the Collider Ring. The following two sections will be added soon: DC Cooling in the Booster Ring (Needs some simulations for this topic.), Optimization of the electron cooling efficiency.
- Others
- -Reviewed two papers
- -Work plan in the following two weeks
- -Continue writing and polishing the pCDR report
- -Some coding for the kernel-independent FMM
- -Dust particle transport
- -Understand the dispersive cooling theory

**Diagnostic Development - K. Jordan**

*No report*.

**LERF - S. Benson**

- May 14-25
- Derived draft budget for isotope production
- Went over isotope project with DOE site office staff
- Summarized labor resources needed for FOA proposal
- Continued cleaning up the LERF for isotope visit.
- Attended teleconference with DOE for isotope project.
- Hosted Cooling ring meetings on May 16 and 23rd and wrote up minutes
- Established CCR circumference for Pre-CDR
- Reviewed IRMMW paper, LDRD proposals and IPAC contribution

- May 29-June 8
- Arrange for collaboration with HZDR for Elbe II facility.
- Submit budget for isotope project
- Complete AWP for FOA proposal
- Revise LOD to match new ASE document.
- Complete question answers for LDRD proposals
- Review a couple of AIP papers