2017-02-17

Director - M. Spata

No report.

---

Accelerator Physics
- T. Satogata

Todd Satogata

 Previous two weeks (Feb 6-Feb 17)
   - JACoW: board of directors telecon
   - ADMIN: Annual review meetings, CASA group meet
   - OPS: Hall D run setup/support; BTeam org, beam studies; Optics Feb 7-14
   - HALLD: GlueX collaboration meeting/talk (Feb 16-18)
   - IPAC18: SAB invitation management
   - JLEIC: Resurrect old gear changing simulations for GHOST collaboration
   - JLEIC: Reading impedance papers
 Next two weeks (Feb 20-Mar 3)
   - OPS: Hall D run setup/support; BTeam org, beam studies; Optics Feb 7-14
   - JLEIC: Work/meetings on ion bunch formation strategy
   - JLEIC: Collective effects, spreadsheet planning and nagging; R&D meet
   - JLEIC: reading impedance papers, start longitudinal simulations
   - JLEIC: Start 4/3 gear changing simulations for GHOST paper
   - IPAC18: Start organizing ideas for invited talk proposals (SPC task)

Alex Bogacz

 Previous two weeks (Feb 6-Feb 17)
   - OPS: Optics support, injector match evaluation
   - PERLE: lattice re-design, Feb trip/presentation prep
 Next two weeks (Feb 20-Mar 3)
   - PERLE:  Orsay kick-off meeting
   - PRAB article review
   - JLEIC: Booster meetings re injection/parameters

David Douglas

 Previous two weeks (Feb 6-Feb 17)
   - JLEIC: Finish up emittance exchange, including example; document;
     first pass appears unworkable
   - JLEIC: Continue work on CCR arc requirements tech note and arc design
   - ADMIN: Accelerator TRC review memo (later rendered irrelevant)
   - PERLE: Feb trip/presentation preparation (operations driven I&C)
 Next two weeks (Feb 20-Mar 3)
   - JLEIC: Write up of emittance exchange slides/tech note
   - JLEIC: Return to CCR arc requirements document, CCR architecture
     concepts document, and ERL/CCR beam exchange system requirements

Rui Li

 Previous two weeks (Feb 6-Feb 17)
   - Feb. 6-10: survey impedance budget studies, prepare and make
     presentation at the JLEIC R&D meeting
   - Feb. 13-18: understanding the state-of-art for the
     potential-well effect and the longitudinal single-bunch
     instability
 Next two weeks (Feb 20-Mar 3)
   - Feb. 20-26: understanding the logic and assumptions of ZAP, and
     see how its input can be related with the JLEIC
     database. Estimating JLEIC single bunch effects.
   - Feb. 27-Mar. 5: further understanding of the state-of-art for
     transverse single-bunch instabilities
   - Cheng-Ying needs more time to refine his thesis, so I expect to
     read and review it in a few weeks

Ed Nissen

 Previous two weeks (Feb 6-Feb 17)
   - JLEIC: Continue implementing gear changing script model for
     Guinea Pig for 4/3 gear changing evaluation
   - JLEIC: Continue evaluating/planning Booster injection design,
     literature search
   - ADMIN: Fighting with MFA (took a few days)
 Next two weeks (Feb 20-Mar 3)
   - JLEIC: Continue writing PRSTAB paper draft on beam-beam sims,
     iterate with Daniel Schulte at CERN
   - JLEIC: Continue implementing gear changing script model for
     Guinea Pig for 4/3 gear changing evaluation
   - JLEIC: Finish literature search, start documenting parameters
     for calculations and future simulations

Chris Tennant

 Previous two weeks (Feb 6-Feb 17)
   - JLEIC: analysis of CCR-like arc with collective effects (space
     charge, CSR, space charge + CSR) (it ain't good)
   - JLEIC: analysis of mitigation of CSR wake using RF cavity in
     circulator ring (still ain't good)
   - JLEIC: analysis of merger performance at 2 nC (it ain't good)
   - JLEIC: started combing through 2 years of
     notes/slides/TNs/results to summarize work done for the
     ERL-driven cooler concept (i.e. the previous baseline)
 Next two weeks (Feb 20-Mar 3)
   - JLEIC: continue work on aforementioned TN
   - JLEIC: simulate Slava's/Dave's emittance exchange (probably
     ain't good)

Randy Gamage

 Previous two weeks (Feb 6-Feb 17)
   - JLEIC: Continue BLonD simulations of debunch/rebunch with impedance
   - JLEIC: Longitudinal impedance reading
 Next two weeks (Feb 20-Mar 3)
   - JLEIC: Continue BLonD simulations of debunch/rebunch with impedance
   - JLEIC: Continue Longitudinal impedance reading, calculations
   - JLEIC: Continue writing outlines of initial dissertation chapters

---

Accelerator R and D - Y. Zhang

Slava Derbenev

   - Conceptual development of emittance exchange. Worked out one solution which was proved independently by David Douglas using a different method
   - Unified field theory study 

Fanglei Lin

   - Continued chromaticity compensation studies on electron ring optics and presented the progress in the bi-weekly non-linear beam dynamics meeting.
   - Helped write a document describing the Compton/forward electron detection region in the JLEIC.
   - Provided the electron ring lattice for beam-beam study in the JLEIC.
   - Provided the positron luminosity parameters per nuclear physicists’ request.
   - Miscellaneous: attended the CASA monthly meeting, attended the beam-beam code development meetings, attended JLEIC weekly R&D meetings, attended JLEIC parameter/Ion injector coordination meeting, attended the bi-weekly non-linear beam dynamics meeting, attended the bi-weekly ion polarization meeting, attended the bi-weekly simulation meeting. 

Vasiliy Morozov

   - Crab crossing: working with Salvador on crab dynamics simulations
   - Beam-beam simulations: generating high-order maps for current collider ring lattices
   - Ion polarization: planning for further work
   - Detector background: documenting detector region configuration
   - Non-linear dynamics: optimization of the electron collider ring
   - Heavy ion tagging LDRD: analysis of forward detection performance
   - Miscellaneous: muon ionization cooling, positron working group and workshop planning, translation of Slava's thesis on electron cooling, detector simulations 

Amy Sy

   - Skew PIC: Compared phase space plots and beam sizes over 101 periods in Skew PIC channel for aberration compensation using ordered vs. arbitrary harmonics. Arbitrary harmonics (periodic with Skew PIC cell but not sine/cosine like) tend to give smaller beam size but will need to be optimized using genetic algorithm techniques to handle large variable sets. Started implementing Chebyshev expansion of magnetic field into MADX with the goal of finding better representation of multipole fields needed for aberration compensation.
   - Merger: Working on verifying properties of generated magnetized particle distribution and its transport through the associated "matched" solenoid. 

Guohui Wei

   - Simulated 10000 events of ePb collision in JLEIC IR　section. Preliminary analysis all particles generated by collisions at IP and downstream area, like the exit of the third final focus quadrupole, the exit of the second dipole, and the second focus point.
   - Continuing on dynamic aperture study with tune scan for the JLEIC ion collider ring.
   - Prepare for the proceeding paper in IPAC'17 

Yuhong Zhang

   - Developed a program for the JLEIC spring collaboration meeting
   - Developed a plan and had a meeting for the next bunched beam cooling experiment in April
   - Studied report of DOE EIC Accelerator R&D Review
   - Attended various meetings 

---

Computational Physics - Y. Roblin

He Zhang:

   - Cooling simulation - Now the program can track the ions by a turn-by-turn method during cooling. The program will take the betatron oscillation tunes and the synchtron oscillation tune, construct the transfer matrix, and use it in tracking. Later we can add a feature of tracking with maps, if necessary to study some other effects.
   - Dust particle transport Read through some papers again, focusing on the following three topics: pick-up of the dust particle, transverse stability of the dust particle’s motion, and longitudinal motion of the dust particle. Basically, the dust particle could be picked up due to its own thermal energy or the field of the beam. . Because the longitudinal velocity of the dust particle is much slower than that of the beam, during the time for the dust particle to transport a few meters, many (probably up to a million) electron bunches have passed the dust particle. Each bunch gives it a kick. If the motion is not stable, it is difficult to image the dust particle can survive so many kicks. Now I think the motion should be stable and a critical charge to mass ratio could be calculated. If the charge density of the beam is not uniform, it will give the dust particle accelerations in the longitudinal direction. Once I finish the summary, I’ll discuss with Rongli what to calculate. (meeting is scheduled monday at 11am)
   - NSF proposal - Finished and submitted the NSF proposal on “Mesh-free method for space charge effect simulation with boundary of arbitrary geometry”. Based on the review, I think there are two things to improve. First, the reviewers want a specific example that will benefit from this method. Second, the reviewers think we just use old algorithms and do not contribute to computational physics. I basically worked on the second point. Add descriptions on the new algorithms, traceless FMM for Coulomb interaction and kernel independent FMM using differential algebra. We fail to make solid improvement on the first point. So I think we will take time to improve the proposal, although it has been submitted.
   - Cooling theory study - Continue the study and had a meeting with Slava, Yuhong and Vasiliy. We discussed an old paper from Slava. But later we decided to study Slava’s thesis, since there is a more complete and systematic description of the theory.
   - Trip rate/heat load optimization - I started to write an IPAC’17 paper on the trip rate/heat load optimization. (Finished one page till now.) Submit a proposal for SULI summer studentDust particle transport 

Yves Roblin

   CEBAF: 
   - working on improvements to optics model. In particular ways to exploit the signals from the M56 cavities to do global tunings of the arcs.
   - BEM algorithms being reviewed still. We now have a second version of BEM which runs in parallel with the real one in order to study the adequacy of the algorithms parasitically.
   JLEIC:
   - Organizing meetings for the simulations.
   - Installed Beam Beam 3D on the JLAB clusters
   - Starting running BB3D simulations of the EIC 100/5 setup.
   - Working on extracting generating functions from a symplectic map. This is something we would like to do in order to have GHOST directly use maps coming from MAD-X instead of COSY.
   - Read the EIC report. Preparing a list of simulation related activities one has to prioritize according to this report.

---

Diagnostic Development - K. Jordan