February 1 2019 Report - Jan 21 - Feb 15
Director - Todd Satogata
Previous two weeks (Jan 21 - Feb 1) - Next two weeks (Feb 4 - Feb 15) -
Previous two weeks (Jan 21 - Feb 1) - Finalize Arc 1 and Arc 2 re-design - Vacation - Conferences and Publications Committee: kick-off mtg Next two weeks (Feb 4 - Feb 15) - Fine-tuning of gamma_t for FODO lattices - Machine support - PRAB paper review - Grad Student Steering Committee mtg.
Previous two weeks (Jan 21 - Feb 1) - FMLA - Catching up on work after a long leave Next two weeks (Feb 4 - Feb 15) - Planning for the next impedance meeting - Look at collective effect for pCDR-100GeV
Previous two weeks (Jan 21 - Feb 1) - Work on lattices for new JLEIC boosters - Machine Access Control training - Vacation. Next two weeks (Feb 4 - Feb 15) - Finishing MAC training. - Continue work on the new boosters
Previous two weeks (Jan 21 - Feb 1) - Preparing LDRD on machine learning - Machine learning meeting at ODU Next two weeks (Feb 4 - Feb 15) - Organizing lunch talk series on machine learning - Investigating uses of machine learning at JLAB
Accelerator R & D - Yuhong Zhang
Previous two weeks (Jan 21 - Feb 1) - Considered various issues and potential optimization (IR, cooling) for 100 GeV CM energy JLEIC - Prepared FOA report (cooling simulation, bunched beam experiment and coherent electron cooling - Prepared talks for Hong Kong High Energy Physics Program Next two weeks (Feb 4 - Feb 15) - Attend the HK HEP program in the second experiment - Make planning of Lijun Mao's visit - Planed spring JLEIC collaboration meeting
Previous two weeks (Jan 21 - Feb 1) - 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 (Feb 4 - Feb 15) - Work on the electron collider ring design with PEP-II magnets - Work on the storage ring cooler project - Electron spin study using BMAD
Previous two weeks (Jan 22 - Feb 1) - Nothing to report Next two weeks (Feb 4 - Feb 15) - Nothing to report
Previous two weeks (Jan 22 - Feb 1) - Spin transparency experiment: teleconference with collaborators and calculation of the spin response function of RHIC - Redesign of ion interaction region for 200 GeV - Preparation of the DoE quarterly reports - Miscellaneous: postdoc interview, storage ring cooler, collimation Next two weeks (Feb 4 - Feb 15) - Completion of the DoE quarterly reports - Ion IR and collider ring design - pCDR update - Spin transparency simulations
Previous two weeks (Jan 22 - Feb 1) - Served on the review committee covering the primary and neutrino beamlines as part of the DOE/SC review of LBNF/DUNE at Fermilab. - Wrote and submitted the Beamline portion of the final report. - Met with Zack Conway and Brahim Mustapha at ANL to discuss the JLEIC ion linac. Discussed polarization tracking, H- intrabeam stripping, and stripping chicane design/optimization as paths for further design studies. Working with Brahim to get the latest Trace3D and TRACK inputs for the LEBT and full linac designs. Next two weeks (Feb 4 - Feb 15) - Continued work on getting the TRACK code running with the latest version of the JLEIC ion linac lattice. - First looks at IMP cooling data from December 2018 to start informing Spring 2019 experimental goals.
Computational Physics - Yves Roblin
Previous two weeks (Jan 22 - Feb 1) - CEBAF: setting up machine for spring run developing metrics for machine assessment - OTHER: Meeting at ODU for machine learning collaboration. - Defining machine learning problem for possible collaboration Next two weeks (Feb 4 - Feb 15) - Continue work from previous weeks
Previous two weeks (Jan 22 - Feb 1) - Nothing to report Next two weeks (Feb 4 - Feb 15) - Nothing to report
Previous two weeks (Jan 22 - Feb 1) - JSPEC code development - RF Voltage calculation module has been finished and tested. This feature has been merged into the main branch and pushed to Github. When the bunch size is chosen to be constant, jspec will calculate the RF voltage with respect to the momentum spread at each time step. The voltage is saved in the last row of the user- specified output file. When the bunch size is allowed to vary with the momentum spread. The RF voltage is calculated once. But it is still saved as above on each time step. - Space charge field of the electron bunch results in both the longitudinal velocity shift and the transverse velocity shift of the electrons. The longitudinal velocity shift is due to the electrostatic potential difference according to the different radius. The transverse one is due to the collective effect of the radial space charge field and the longitudinal magnetic field. In the perspective of the friction force calculation, both velocity shifts change the relative velocity between the ion and the electron while the transverse one also changes the electron temperature (Larmor emittance). With the help of some references, the formulas of the velocity drift for a uniform round electron beam (bunched or coasting) are derived and documented. These are good enough for IMP experiment. For a uniform flat beam, one may have to do numerical integration. The code is still under development. - For the core-tail model, I am working on the multidimensional fitting algorithm using the gradient descent method. Next two weeks (Feb 4 - Feb 15) - Finish the core-tail model and the space charge effect in friction force calculation. - Continue documenting JSPEC development. - Prepare data, plots, and poster for the DA based kernel independent FMM.
Diagnostic Development - Kevin Jordan
Previous two weeks (Jan 22 - Feb 1) - LCLS-II modules are now at 2K in the lerf. Activity centers now on getting the RF interlocks tested, once this is complete Rama will submit a signed off check list to Arne. That is the point that Arne will authorize the operation of the Solid State Amplifiers (SSAs). The next steps are to tune the cavities, then adjust the couplers for proper Qext, then Emax & Q0. - I submitted 2 invention disclosures; Use of Litz wire to improve grid performance & use of direct induction to speed blackout of vacuum systems (Matt Polker lead) - I submitted ATLis for replacing beam viewer flag at ITV7A09 with BNNT buckypaper during the April down when the first of the SLM vacuum chambers is installed. Next two weeks (Feb 4 - Feb 15) - Start LCLS-II cavity retesting - Isotope beam line & target layout
Previous two weeks (Jan 22 - Feb 1) - Complete a design of the movable radiation shielding for the Isotope production project. Received positive feedback on the design by RADCON and waiting for feedback from the project manager and the consultant engineer before progressing. Started initial design for an imager upgrade to ITV7A09. Started some assembly of the ARC 7 SLM Next two weeks (Feb 4 - Feb 15) - Should be receiving components for the ARC 7 SLM and x-ray viewer this week. Will start assembly of those as materials arrive. Will continue working on the ITV7A09 imager and radiation shielding wall.
Previous two weeks (Jan 22 - Feb 1) - Magnetic calibration assessments - Harp data structure revision still being planned; expect in upcoming two weeks to complete a proposal for review. - Assessment of beam envelope tolerance to momentum mismatch vs. quads. Hope to schedule at the January accelerator turn-on. - Continuing goal to push magnet system diagnostics into procedures for DC Power Next two weeks (Feb 4 - Feb 15) - I seem to be less capable than I expected, and these still lag. The magnet lab folks are configuring their hardware to check fundamental calibrations from the upgrade, and I've been involved in diagnosing problems with canceling remanent field in the injector spectrometer. However, the analysis for dipole stand rotation in elogs 3646334, 3646793, and 3646813 seems interesting and useful. It _appears_ that the dipole stands may have suffered two separate episodes of tilting: one in Mar/Apr 2015 and one across the Christmas downtime from Dec 2015 to Jan 2016. - Continuing with all of the above, with the addition of attempting to identify which stands of the arcs were significantly tilted. It seems likely to be able to field absolute orbit analysis which will identify systematic errors such as this or ground motion, giving us early warning of deviations. Regularly running such analysis processes and archiving the time course would provide readily available "figures of merit" for tracking and reference.
LERF - Steve Benson
Previous two weeks (Jan 22 - Feb 1) - Stood in for T. Satogata in his absence - Wrote up budget for Isotope quarterly report. - Submitted quarterly reports for FOA and Isotope project. - Completed and helped to submit FOA proposal for micro bunching measurements at CBETA Hosted cooler ring meetings to go over the impact of the new booster configuration - Worked on property validation. - Submitted laser safety checklists for the LERF. - Trained J. Gubeli and J. Musson for User Lab 4 laser safety. - Developed specifications for the isotope beam line dipoles power supply Next two weeks (Feb 4- Feb 15) - Submit new text for LOD and safety envelope for LERF. - Summarize the ERLs for EIC workshop. - Develop MPS specifications for isotope runs. - Review coherent cooling literature and establish specification baseline Get new simulations for Pre-CDR-100 Write up new draft for Pre-CDR-100 chapter 6 Review invited talk suggestions for FEL 2019 Hold cooler ring and FOA coordination meetings. - Hold seminar committee meeting to establish Winter/spring schedule.
Previous two weeks (Jan 22 - Feb 1) - I returned from Europe on February 2. I had completed my report for the HCERES Review at Orsay while on vacation. I spent a couple of days finishing my report for the AMICI Meeting, then wrote a trip report to management for both meetings, including the reports. - I learned that a full-size booster was being adopted for the ion injection chain and realized that this configuration would permit the creation of a bunch pattern that would cancel the gap transients in the RF systems of the Ion Colliding Ring. I then spent a fair amount of time looking at different options. - I came up with a design for a supplemental container for the isotope target crucible. I don’t think this will actually be needed for the isotope program (maybe later when we have higher radiation levels in the crucible). However, the design could be used much more widely so I have submitted an invention disclosure. - Joe Gubeli and Keith Welch have made great progress with the shielding design for the isotope irradiations and asked for comments. I suggested using a borescope to make sure that the dump closes properly, including the correct positioning of the target wrt the radiator. I also spent time looking at TIMs (Thermal Interface Materials) to improve cooling of the crucible, following a productive discussion with Dave Meekins. The final choice will probably be pure Tin, almost as soft and thermally conductive as Indium, but with a higher melting temperature. - I discussed with Geoff Krafft the possibility of having a summer student to carry out thermal transfer measurements as part of our design effort to develop a crucible capable of dissipating 50 kW. Next two weeks (Feb 4 - Feb 15) - In the next two weeks, I will be finalizing the options for gap transient suppression with Bob Rimmer and Jiquan Guo, itemizing the additional hardware required. The Isotope work looks like it will be on hiatus as the LCLS II commissioning is starting. I am planning a mini-review of the target shielding, but that must await until after Joe Gubeli gets back from California (he is following up on an SBIR contract). - I feel I should be doing something on electron bam cooling, but not sure how to be useful. I have made several recommendations over the last year (APEX gun, lower RF frequency injector, higher harmonic cavities) but these are only now beginning to be examined. I would like to see some results before proposing anything else.