PPB - Oct 28, 2020

Meeting Info

We will meet on Wed (Mexico 10am, US 12pm, France 5pm)
Bluejeans: https://bluejeans.com/164307983

Updates

Joe - Update on spin tracking project

1. Assigning spin component information to a particle (or macroparticle)
2. Implementing the Bargman-Michel-Telegdi time-dependent spin-equation of motion
3. Generally rate of spin motion (ds/dt) is similar to physical motion (dx/dt), but maybe consider how time steps are computed, e.g. when an adaptive time step is implemented
4. Implement methods to define initial spin distribution a) internally (e.g. set sx,sy,sz of particles very useful for testing) or b) externally (e.g. to accept a distribution originating from another code like Geant4 output)
5. Evaluate numerical test cases of 'pure fields' (e.g. B_perp, B_axial, E_perp, E_axial) or single elements (e.g. dipole, solenoid, e-field deflector) against analytic solutions
6. Evaluate numerical test case of field map (e.g. we have ExB wien filter field maps, solenoids, cavity)
7. Saving the spin component information, similar to other arrays, in output file
8. Ability to display spin component (or polarization = average of sx, sy or sz) in GUI would be useful

From last meeting

LDRD Q1 Goals (Oct-Nov-Dec)

• Identify graduate student and new hire post-doc for Q2 start date
• Develop a GPT interface to Geant4 and test spin tracking of positrons
• Review of past positron source, literature, discussions with experts
• Develop framework for simulations using analytic calculations

Recent & upcoming meetings...

• Americas Workshop on Linear Colliders (Oct 19-22)
• Jefferson Lab Accelerator Advisory Committee (Oct 20-23)
• APS Division of Nuclear Physics (Oct 29-31)