# 2019-01-18-LeadershipReports

From Administrative

Jan 7-Jan 18

**Director - Todd Satogata**

Previous two weeks () - Next two weeks () -

Alex Bogacz

Previous two weeks () - Next two weeks () -

Rui Li

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Ed Nissen

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Chris Tennant

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

Fanglei Lin

Previous two weeks (Jan 7 - Jan 18) - Optimizing the electron collider ring design with PEP-II magnets - Working on the storage ring cooler project - Miscellaneous: attended the spin transparency test teleconference, attended the Pre-CDR Update 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 18 - Feb 1) - Work on the electron collider ring design with PEP-II magnets - Work on the storage ring cooler project - Electron spin study using BMAD

Vasiliy Morozov

Previous two weeks (Jan 7 - Jan 18) - Next two weeks (Jan 18 - Feb 1) -

Amy Sy

Previous two weeks (Jan 7 - Jan 18) - Next two weeks (Jan 18 - Feb 1) -

**Computational Physics - Y. Roblin**

Yves Roblin

CEBAF - Prepare for machine startup. - Preparing talk to Hall A collaboration. - Completed TOSP for Hall A Apex Experiment - Developing method to center solenoids (in particular Hall A moeller solenoid) - BTEAM JLEIC: - Reviewing Implications of the 100 GeV CM setup for BeamBeam OTHER - Attended workshop on ML - Conducted interviews for postdoc position - TRC meetings - FOA reports. - Evaluating various Python frameworks for ML and GA (DEAP, pyEVOLVE)

He Zhang

Previous two weeks (Jan 7 - Jan 18) - Development of JSPEC code - DeCooling Rate Calculation for JLEIC with New Parameters - BeamBeam3D - River helped me to repeat Sergei’s deriving of the Bjorken and Mtingwa (BM) formula for the IBS rate calculation using the elliptical integral and to check whether we can extend Sergei’s method on a general case including vertical dispersion and all the missing terms in the oringal BM formula. Our current conclusion is the total rate, summation of the rates in all the three directions, can be calculated using Sergei’s formula, as long as we calculate the eigenvalue of the I matrix, which is related to the dispersion matrix, numerically. Since the I matrix is a symmetric real matrix, its eigenvalues can be calculated using some routine algorithm. We failed to find the explicit formula for the rate in each individual direction. To find the formula, we need explicit expression of the eigenvalue, which does not exist for a general matrix I. I have an idea of decompose the I matrix into three parts, treat them separately and take the summation. But I am not positive this method gives correct or approximate answer. Next two weeks (Jan 18 - Feb 1) - The core-tail model for non-Gaussian IBS is in process - Finish space charge effect in friction force calculation - Continue documenting JSPEC development - Electron beam Space charge effect on friction force calculation is in process. - Cooling Rate Calculation for JLEIC with New Parameters - In the new parameter set of JLEIC, the proton beam emittance and bunch length at the collision energy have been increased to mitigate the severe IBS effect. For the 63.3 GeV CM energy case, the collision frequency has been changed back to 442 MHz, hence the charges per bunch has been significantly reduced, which helps to achieve a milder IBS effect. The cooling rate and the IBS rate are calculated for both the 44.7 GeV CM energy and the 63.3 CM energy. 3.2 nC/bunch electrons provide enough cooling for both case. The challenge is still the distribution of the cooling. As usual, we have very strong IBS effect in the horizontal direction and very strong cooling effect in the vertical and longitudinal direction. - BeamBeam3D - Yu Luo send me the MAD-X lattice file for RHIC at 250 GeV. With Vascily’s help, I am able to generate the truncated map using the PTC package in MAD-X. This lattice file does not include any RF cavity, so the 4D truncated maps are generated. When tracking up to 1 million turns with a 2nd order map, phase space increase happens. When we perform symplectic tracking using our codes, the phase space volume conserves in the 1 million turns. All four kinds of generating functions have been tested and they all work as expected. When using the 3rd order truncated map in tracking, no noticeable phase space distortion is observed in up to 1 billion turns. This may be because that this lattice does not include the high nonlinear sections, such as the interacting region. Others - Write for three FOA quarterly reports - Work plan in the following two weeks - Finish the core-tail model. - Finish space charge effect in friction force calculation. - Continue documenting JSPEC development.

**Diagnostic Development - K. Jordan**

*No report*.

Joe Gubeli

Previous two weeks (Jan 7 - Jan 18) - Worked with several groups in preparing the two LCLS-II CMs for cool down. With a lot of help we were able to successfully cool them both down to 4K and collect liquid. - Completed the design of a new x-ray insertable viewer for the Bubble experiment in the 5D line. Most of the parts have arrived and I have submitted drawings to the MS for fabrication. - I have received the four new chambers for the Arc 7 SLMs, they look really nice. I submitted the chamber support drawings for one set to the MS and they are awaiting signatures. Hint-hint. - I work with Jianxun Yan on moving a linear motor with EPICS. After getting all of the parameters both in firmware and in EPICS correct we were able to move the motor smoothly. A similar motor on a linear slide will be used for Radiabeam's high power-high speed wire scanner (HSHPWS) to be installed in the BSY.

Next two weeks (Jan 18 - Feb 1) - Some time on the HWHPWS in preparing a presentation for OPS and in helping Jianxun. - Most of the time will be spent in designing the shielding (with a movable wall and target) for the Isotope project. I will also need to work some on thermal simulations for this project as well. - I will also be helping with Hot Checkout of the LERF, mainly with the viewers. The video switch partially works and we have no trigger so no Beaminizer.

**LERF - S. Benson**

Previous two weeks (Jan 7 - Jan 18) - Interviewed one candidate for postdoctoral position - Wrote up draft of quarterly report for FOA project - Met with SRF to develop harmonic kicker purchasing strategy. - Met with seminar committee to get new member and schedule new talks - Recruited invited talks for the High Brightness Beams 2019 workshop and the FEL 2019 conference - Derived new linac layout for the cooling ERL for Pre-CDR-100. - Met with CSI personnel to derive specifications for LERF commissioning specifications

Next two weeks (Jan 18 - Feb 1) - Submit new text for LOD and safety envelope for LERF. - Summarize the ERLs for EIC workshop. - Write up budget for Isotope quarterly report. - Submit quarterly reports for FOA and Isotope project. - Review coherent cooling literature and establish specification baseline