2017-Apr-17 Accel. R and D Biweekly Report

Slava Derbenev

• Continued conceptual study of JLEIC
• Advise He Zhang on cooling theory study

Fanglei Lin

• Helped prepare the presentations of electron collider ring nonlinear beam dynamics study and electron polarization for the JLEIC collaboration meeting.
• Attended one-week HIAF project review at Lanzhou in China.
• Miscellaneous: attended a discussion of IR magnet specification.

Vasiliy Morozov My main activities in the past two weeks were:

JLEIC collaboration meeting: presentations on polarization and IR design
• Ion polarization: IPAC'17 paper preparation and solenoid compensation work
• Geometry tagging LDRD: teleconferences with collaborators and 2nd-year proposal preparation
• IR magnet design: discussions with Peter McIntyre and Tim Michalski
• Synchrotron radiation mask and detector background simulations: discussions with Mike Sullivan and Latifa's group
• Crab crossing design and simulations: work with Salvador Sosa
• Muon cooling teleconferences

Amy Sy

• Skew PIC: Finding better solutions for nonlinear compensation by simultaneously optimizing many multipole components to control distributions with large angular spreads - previously gradually incremented the multipole order along with incrementing the angular spread. Found sextupole and octupole components that control particles with angles up to 82 mrad, where previously decapoles were needed to control the same distribution. Also analyzing the linear transfer matrix for the Skew PIC channel to see how the dynamic behavior changes with the introduction of RF - parametric resonance behavior is appears in the presence of RF, and we may be hitting another resonance.
• Merger: Refined the transition section geometry and introduced a tip angle to solenoid coils in the major bend section to offset the vertical drift of the beam center. Generalized emittance evaluation method by removing the artificial longitudinal cut imposed by the emittance calculation program - working on verifying emittance projections on tilted detector planes. Working on adding space charge into the simulation.
• Ion sources: Ran polarized ion source discussion with input from potential contributors from Muons, Inc. and Argonne. Reviewing background material on ABPIS and previous Muons, Inc. proposal narrative in anticipation of future communication with potential Argonne collaborators.

Guohui Wei

• Did analysis of ePb collision in JLEIC IR　section. Currently 10,000 events are studied. Due to the correlation between evaporation neutrons and impact parameter (b), the path length traveled in the medium following the first collision, the results are reasonable.
• Dynamic aperture study with tune scan for the JLEIC ion collider ring in cluster.
• Prepare for the proceeding paper in IPAC'17

Yuhong Zhang

• Attended JLEIC Collaboration Meeting
• Had discussions with external participants of the collaboration meeting
• Completed two IPAC posters
• Prepared to attend the cooling experiment
• Started writing the IPAC papers