Director - M. Spata
No report. Acting Accelerator Division Head
Accelerator Physics - T. Satogata
Accelerator R and D - Y. Zhang
- Continued single particle nonlinear dynamics study for the electron ring.
- Prepared and presented a talk at the JLEIC spring collaboration meeting.
- Investigating JLEIC collider rings’ geometry to fit in the Jlab site.
- Miscellaneous: attended JLEIC general meeting.
- Mar 17 - Mar 30
- Preparation for and participation in the JLEIC collaboration meeting
- Work on a new version of the ion collider ring design
- Polarization: teleconference with Anatoliy's group and discussion of an optimized electron spin rotator
- Revising the scopes and budgets of both funded and unfunded FOA proposals
- Detector design: work on the ion orbit correction scheme
- Geometry tagging LDRD: teleconference with collaborators
- Mar 31 - Apr 13
- Reducing the collider ring circumference
- Preparation of two talks for DIS'18
- Preparation of two papers for IPAC'18
- Set up WARP simulation environment to model two counter-propagating magnetized beams; considering the effect of one interaction between the beams at some point along the accelerating path, but not necessarily in an accelerating field. Implementing diagnostics to track particles that cross specified longitudinal planes to evaluate emittance growth. Setting up proper simulation weights and collision operators. Discussions with Slava on compensation of transverse kick applied to the accelerating beam by setting proper phase of a second kick, such that the induced Larmor rotations cancel out.
- Worked with S. Wang to contribute slides on transverse feedback systems relevant to the ion ring for his talk on feedback system requirements at the JLEIC Spring 2018 Collaboration Meeting.**Participated in the JLEIC Spring 2018 Collaboration Meeting.
- Reviewed polarized ion source requirements and resonant charge-exchange ionization for a discussion on a possible LDRD proposal on a laser driven polarized D- source for JLEIC.
- Prepared report of "Dynamic Aperture and Detector Solenoid Compensation" for the JLEIC Collaboration Meeting Spring 2018. And presented it on Tuesday, 27 March 2018
- LDRD study of the geometry tagging after the collision. An alternative method to measuring the evaporation neutrons is to detect the residual nucleus. Measuring its magnetic rigidity (~ A/Z), is straightforward as it changes substantially for nuclei that evaporate many neutrons. Detection extremely close to the beam is not needed.
- I continue to study the decoupling in IR of ion collider ring with nested skew quads in upstream triplet. an effect analogous to quadrupole rotation can be dynamically produced by appropriately combining a normal quadrupole component (strength: kn) and a skew component (strength: ks).
- Organized the JLEIC collaboration meeting, gave 3 talks
- Gave a presentation in JLEIC general meeting
- Attended cooling experiment teleconference
- Prepared slides for an invited talk at APS meeting
- Explored a LDRD for small aperture magnets for JLEIC
Computational Physics - Y. Roblin
- Mar 17 - Mar 30
- -Prepared slide for A. Boenhlein for ADP report
- -Parameter table studies. Attended meetings, simulated hall a configurations. Finalized table
- -Updated Dennis T. job description
- -Support/setup of CEBAF for restart
- -Technote writing/analysis
- -TRC committee meetings
- -Prepared talks for the JLEIC collaboration, delivered talks.
- -Met with collaborators, wrote milestones for the FOA, submitted report to DOE.
- Vacation: Mar 29, Mar 30
- Mar 31 - Apr 13
- Interview panels for Rad Physicist position
- Beam studies/machine restart for CEBAF
- Organizing FOA (setting up budget, acct code, etc..)
- Reading articles on multivariate polynoms evaluation schemes
- Management training.
- Mar 17 - Mar 30
- JSPEC Development - A hollow beam model is added for both coasting and bunched electron beam. As Slava suggested, putting the electron beam at the edge of the ion bunch may provide larger friction force. This is true for a single ion. But, if we consider the whole bunch, it also means less ions see the electrons. I need to do some simulations with the hollow electron beam to check what we can achieve. Fixed a few bugs reported by Paul at Radiasoft.
- Extend the tpsa code - This is considered done for now. I have cleaned up the code, added doxygen comments, and written cmake files to generate static and shared library. I also compared the new code with the original code and see an improvements of efficiency. A brief introduction about the changes and how to use the code is written. Although I think the efficiency can be further improved, but there is no urgent need for it. Besides being used in the kernel-independent FMM, the code can be used in other codes we are developing. For example, in GHOST, the users need to provide both the transfer map and the ODE of the generating function. The latter one may be not very straightforward for the users. Actually, it can be generated from the transfer map using some differential algebra based algorithm. With the help of the tpsa code, we should be able to re-do the DA algorithm and generate the ODE. Then the transfer map will be the only input needed for GHOST.
- JLEIC Cooling Simulation - Did some simulation with 1.6 nC/bunch electron beam as Steve suggests. As expected, the difficulty is still the imbalance of the IBS in different directions. Longitudinal cooling is still too strong. If we reduce the proton beam current, we can find an equilibrium state. However, some cooling is wasted. Assuming the proton bunch length constant is helpful. But I think we should/could be able to improve it.
- Others - Reviewed two papers. (Only one paper left. Not accept more reviews before we finish pCDR report.)
- Mar 31 - Apr 13
- Finish the draft on cooling simulation for JLEIC baseline design. (This is needed for both IPAC and pCDR)
- Do some simulations on cooling with dispersion and write down the result together with Slava. (This is also needed for both IPAC and pCDR)
- Add turn-by-turn cooling simulation and an RF model to JSPEC and do some simulations for IMP experiment. (Haipeng needs it.)
- The last review is due.
Diagnostic Development - K. Jordan
LERF - S. Benson
- Prepared and presented three talks at the Collaboration meeting
- Attended the collaboration meeting.
- Made some good progress in deriving the specifications for the cooler ring solenoid
- Started to go over the details of the CeC micro bunching proposal that was funded.
- Had some discussions with P. Evtushenko about HZDR upgrade.
- Worked out some property issue for G Biallas and D. Douglas to make sure their property was properly transferred.
- Prepare for and attend the FACET II Director's review at SLAC April 10-11.
- Continue to derive the specifications for the Cooler ring solenoid.
- Host Cooler ring meeting on April 4th.
- Lay out the cooler ring section of the preCDR in more detail. Decide on near term tasks.