February 15 2019 Report - Feb 4 - March 1
Director - Todd Satogata
Previous two weeks (Feb 4 - Feb 15) - ADMIN: Organize/run monthly CASA group meeting - ADMIN: Review Phys Rev Letter paper - ADMIN: Working postdoc interviews, hires, accounting, offer letter - JLEIC: pCDR-65 updates, test printings; pCDR-100 fork - JLEIC: pCDR/ion complex meetings, parameters, configuration convergence - ODU: Sarah Solomon emails re JLEIC modulational diffusion - OPS: Optics on call (Feb 12-19), operations meetings - USPAS: File final grades, student post-class emails - HOLIDAY: Feb 8 - VACATION: Feb 15 (half day) Next two weeks (Feb 18 - March 1) - ADMIN: Group administration: expectations, justifications, quarterly - ADMIN: Postdoc interviews, hires, accounting, pursue offer letter - ADMIN: Recommendation letter for high school student (Darren Upton) - JACOW: IPAC18 delegate survey report - JACOW: Template updates for IPAC'19 - JLEIC: Booster vacuum tech note development - JLEIC: pCDR-100 development, planning; P&C meeting (Feb 17) - NAPAC19: JACoW assistance with PayPal payment system - OPS: GlueX collaboration meeting (Feb 21)
Previous two weeks (Feb 4 - Feb 15) - Fine-tuning of gamma_t for FODO lattices - Machine support - Conferences and Publications Committee work - Grad Student Steering Committee mtg Next two weeks (Feb 18 - March 1) - Optics-on-Call, Machine support - Organize semi-annual progress review of grad. students in Accelerator Science - REU/SULI students selection - PRAB paper review - Putting together a TN on Fine-tuning gamma_t for FODO lattices
Previous two weeks (Feb 4 - Feb 15) - JLEIC impedance - Set up impedance meeting - Fixing the computer problems of the impedance wiki page - Schedule next impedance meeting (learn to use outlook calendar with the help from computer center) - Impedance discussions - Discuss with Vasiliy on collimator and IR region design impedance issue - Discuss with HyeKyoung about crab impedance progress, and help her with understanding of coupled bunch instability paper by CERN - JLEIC collective instabilities for higher energy design - Help Vasiliy to find the lower limit of injection energy above the transition energy, by looking at the thresholds for the single bunch longitudinal and transverse instabilities - Continue to develop more understandings on collective instabilities - Other activities - Attend meeting with Bas (author of GPT) and discussed with him about their CSR implementation and comparison with experiment - Help Riad by discussing about the difference of space charge effect for magnetized and non-magnetized beam in the injector Next two weeks (Feb 18 - March 1) - Organize the next impedance meeting (2/22) - Go over the current status of impedance study at JLEIC - Plan for following impedance studies - Work on coupled bunch instability for combined effects of RF and crab cavity HOMs
Previous two weeks (Feb 4 - Feb 15) - Put together ECA application and submitted it - Machine Access Control training - Work on lattices for the new injector chain, in its changing forms Next two weeks (Feb 18 - March 1) - Finishing MAC training. - Finalize the design for the 8GeV booster - Start the geometric matching for the full size booster
Previous two weeks (Feb 4 - Feb 15) - Poster and talk preparation for ML Workshop - Prepared and gave talk at the Computing Round Table's "ML mini-workshop" (2/12) - Participate in "Conferences & Publications Committee" meetings (2/1 and 2/15) - Prepared and launched first ML lunch series (2/13) Next two weeks (Feb 18 - March 1) - Continue moderating ML lunch series - Attend ML Workshop PSI (2/25-3/1)
Accelerator R & D - Yuhong Zhang
Previous two weeks (Feb 4 - Feb 15) - Worked with Jiquan Guo on ion injector design optimization - Developed new baseline parameters associated with different ion injector schemes and assessed luminosity performance - Developed new concepts for enhancing cooling efficiency - Reviewed two Early Career Award pre-proposals - Attended Micro-bunching Cooling meeting Next two weeks (Feb 18 - March 1) - Start organization for Spring JLEIC Collaboration Meeting
Previous two weeks (Feb 4 - Feb 15) - Optimizing the electron collider ring design with PEP-II magnets - Updated the interaction region design in the electron collider ring - Miscellaneous: attended the JLEIC R&D meeting, attended JLEIC general meeting, attended CASA group meeting, attended the IP magnet design meeting. Next two weeks (Feb 18 - March 1) - Finish the electron collider ring design - Work on the storage ring cooler project
Previous two weeks (Feb 4 - Feb 15) - Nothing to report Next two weeks (Feb 18 - march 1) - Nothing to report
Previous two weeks (Feb 4 - Feb 15) - Redesign of the ion IR: multiple iterations with nuclear physicists and engineers, teleconference with collaborators, luminosity working group meeting. Next two weeks (Feb 18 - March 1) - Finalize the design of the ion IR - Ion collider ring design - Spin transparency test experiment - Storage ring cooler
Previous two weeks (Feb 4 - Feb 15) - Prepared and submitted a preproposal for the Early Career Award solicitation titled "Laser-driven Polarized Deuterium Source". The concept was explored earlier in an LDRD proposal and involves the selective excitation of rovibrational states in deuterium or hydrogen halide molecules that then couple to the nuclear spins of the atoms. The nuclear polarization of the deuterium or hydrogen atom is accessed by UV photodissociation. - Prepared sections of the final Muons, Inc. Skew PIC closeout report, particularly on the simulation work for channel design, aberration compensation, and simplified cooling. - Conversion of the Trace3D input for the polarized light ion LEBT into MADX for further conversion into a lattice readable by pyORBIT. Working to understand pyORBIT structure and capabilities for linac tracking. Next two weeks (Feb 18 - March 1) - Received access to the current TRACK input files for the light and heavy ion linacs - the bulk of the next two weeks will be devoted to understanding the TRACK code and starting some short (~150 MeV) linac optimization.
Computational Physics - Yves Roblin
Previous two weeks (Feb 4 - Feb 15) - Nothing to report Next two weeks (Feb 18 - March 1) - Nothing to report
Previous two weeks (Feb 4 - Feb 15) - Nothing to report Next two weeks (Feb 18 - March 1) - Nothing to report
Previous two weeks (Feb 4 - Feb 15) - JSPEC code development - A new feature is added to JSPEC, which is intrigued by Yuhong’s proposal of rotating the ion beam during the cooling process. Because the horizontal IBS expansion rate is much larger than the vertical IBS expansion rate, we can easily reduce the vertical emittance while we have difficulty to reduce the horizontal one. Yuhong’s idea is to rotate the ion beam 180 degree after a period of cooling, so that the original horizontal emittance feels smaller IBS and can be reduced by cooling. After another period of time, we rotate the ion beam back. This rotating and cooling process is repeated in order to achieve an overall better cooling. Intuitively this is similar to the idea of strong focusing. It is difficult to simulate this process using the original UI, because the UI has no access to the computation/simulation results, which are saved in the hard drive. The UI has been enhanced to make this simulation possible. The UI has a special section, the scratch section. Which is actually a math parser. Any variable defined in the scratch section can be used in the following sections. Now a few special variables have been defined in the scratch section and they are used to save the normalized emittance, momentum spread, bunch length, IBS rate, electron cooling rate and time. The values are automatically updated whenever a computation/simulation has performed. In such a way, we can use the final emittance from the previous simulation to defined the ion beam in the current simulation. If we switch the value of the transverse emittances, the beam is rotated by 180 degree. This new feature has been tested and the update has been push to the github repository. As to the IBS rate calculation including the vertical dispersion, I considered the possibility of using the elliptical integral by separating the matrix I into three components, each of which can be treated easily. It turns out this idea does not work after a careful study because the matrix I appears exponentially so that the addition becomes multiplication and we cannot separate them in the way we want. But I just come across a paper that uses the diagonalized matrix I to calculate the expansion rate of the adjusted momentum. The paper also gives the relation between the expansion rate of the adjusted momentum and normal IBS expansion rate. I think it may be possible to use the elliptical integral to calculate the expansion rate due to the diagonalized matrix I. I will investigate this idea later. The user manual of JSPEC has been updated for some new features that has been added recently. I am also writing a note about the electron beam space charge effect calculation. Next two weeks (Feb 18 - March 1) - Prepare data, plots, and poster for the DA based kernel independent FMM and trip to the CES conference. - Continue documenting JSPEC development. - Finish the core-tail model and the space charge effect in friction force calculation.
Diagnostic Development - Kevin Jordan
Previous two weeks (Feb 4 - Feb 15) - Start LCLS-II cavity retesting - Isotope beam line & target layout Next two weeks (Feb 4 - Feb 15) - Continue work from previous two weeks
Previous 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. Next two weeks (Feb 18 - March 1) - Continue working on the ITV7A09 imager and radiation shielding wall.
Previous two weeks (Feb 4 - Feb 15) - Nothing to report Next two weeks (Feb 184 - March 1) - Nothing to report
LERF - Steve Benson
Previous two weeks (Feb 4 - Feb 15) - Nothing to report Next two weeks (Feb 18- March 1) - Nothing to report
Previous two weeks (Feb 4 - Feb 15) - 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 18 - March 1) - 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.