2017-09-01

Accelerator Physics (T. Satogata)
No report

---

Accelerator R and D (Y. Zhang)
Fanglei Lin

• Continued study of the chromaticity compensation and dynamic aperture in the electron collider ring.
• Discussed JLEIC positron parameters with colleagues and prepared the presentation for JPoS17.
• Miscellaneous: attended JLEIC weekly R&D meetings, attended discussion of test CEBAF pulsed mode for JLEIC.

Vasiliy Morozov

• Geometry-tagging LDRD: generating cross-section tables, generating events, analyzing the data.
• JLEIC R&D planning: reviewing R&D activities, preparing for and participating in a conference call with DoE.
• Ion polarization: teleconference with Anatoliy's group about crab crossing effect and its simulation.
• Lower level activities: detector integration, muon cooling, getting started with River on crab crossing work.

Amy Sy

• Application of inverse flat beam transform to low and high energy beam distributions at the entrance and exit of the bent solenoid section. The unrotated inverse FBT recovers the flat beam but swaps the x-x' to y-y' phase space, and vice versa. For both low and high energy beams, there is significant growth in the vertical emittance - the vertical emittance is very small due to the nature of the flat beam, and the growth may still allow for full acceptance into the ERL. The growth of the momentum spread due to space charge effects is likely more challenging - working on lengthening the initial distribution to see how long the 3.2 nC bunch needs to be to avoid 10x growth in the momentum spread through the merger.
• Using tracking data to recover dispersion functions through one period of the Skew PIC channel to allow for alignment of the parametric-resonance-inducing quadrupoles with the angle between dispersion vectors. Nonzero dispersion at the locations where RF kicks are applied to the beam are destroying the development of the parametric resonance, so different methods are applied to recover the characteristic hyperbolic behavior.
• Checked in with Zack Conway of ANL on ion source/SBIR progress. ANL is working with Muons, Inc. to submit an SBIR proposal on the polarized H-/D- atomic beam source. A collaborative effort has been established with BNL for this proposal, and the Phase I proposal is predicated on a Phase II proposal where a BNL polarimeter is modified to test the device that comes out of simulation work in Phase I.

Yuhong Zhang

• Attended bunched beam cooling meeting and discussed with Haipeng/Shaoheng on data analyses
• Discussed with Jiquan on lead ion beam formation scheme and checked space charge limit at various locations
• Discussed with Fanglei and Jiquan on polarized positron source for JLEIC, assisted Fanglei in preparation of JPOS2017 talk slides
• Updated staged electron cooling scheme and ensured design consistence with beam formation, discussed with He Zhang and Jiquan Guo
• Prepared talk slides for the AAC review
• Started preparation of talk slides for COOL17
• Continued to work with BNL for organizing the EIC Accelerator Collaboration Meeting.

---

Computational Physics (Y. Roblin)
No report.

---

Diagnostic Development (K. Jordan)
No report

---

LERF (S. Benson)

August 21 - September 1

• On vacation August 21-25
• Go over frequency choices for Cooler ring gun, injector, and ERL
• Get Kirsten Dietrich started on LERF experiment design
• Completed preparations for Neil symposium
• Help set up safety documents for User Lab 6 experiment
• Assisted Kris Burrows in starting audit of dual use technology items
• Registered for EIC Collaboration meeting

September 5-15

• Prepare talks for JPos17, COOL17, and EIC collaboration meeting
• Attend JPos16 and organize LERF tour