The WARP Code and Recent Simulation Results Hossein

The WARP Code and Recent Simulation Results Hossein Saberi Institute for Research in Fundamental Sciences (IPM) 1 The WARP Code and Recent Simulation Results

General Points Talk in Two Parts: Computer and Physics Parts The WARP results are at the beginning Thanks to Alexey! 2 The WARP Code and Recent Simulation Results

In Today’s Lecture • WARP: Computer-related Issues – Code Installation – WARP Input Script – Data Analysis • Simulation of Self-modulation Instability with WARP • Conclusion 3 The WARP Code and Recent Simulation Results

Using WARP • All about warp: – Developed at Berkeley University – Open-source • – – – https: //bitbucket. org/berkeleylab/warp/downloads/ Particle-in-Cell Code Parallel Fully Electromagnetic 3 D/2 D(XZ-RZ) Python package • WARP Installation – Single-core Version/Installation • • Not Difficult • Not very useful for large simulations – Parallel Version/Installation • • 4 The WARP Code and Recent Simulation Results Needs some python packages to be installed Higher speed, good for large simulation Needs cluster? A bit tricky to install Next slide

Parallel Installation of WARP • Which clusters to run? – CERN batch service (LXPLUS) – CERN HPC cluster – Any other cluster? • CERN batch service – Use htcondor to run the job – Not really MPI parallel • Single node, 8 cores – Good to get used to WARP – Good for initial simulation tests • Install on LXPLUS – Use MPI- MPICH – Install python packages • HPC Cluster – Limited – Access permission recently – Fully MPI • More than ~100 -200 cpu cores – Use SLURM to run the job 5 The WARP Code and Recent Simulation Results

Simulation with WARP • WARP Input Script – Python script – Input parameters • • • – For parallel run of WARP on CERN batch service Plasma Beams – Htcondor runs and manage the job Simulation box Boundary conditions … – Initialize simulation with WARP commands – Using WARP full capabilities needs more knowledge of its python packages 6 • Htcondor submit file The WARP Code and Recent Simulation Results – The condor submit script should include: • • • Source code path directory needed cpus needed RAM/Disk Output directory ….

Outputs and Data Analysis • WARP data outputs – Built-in data outputs in WARP as binary files • • Fields Particles position and momentum Density. . . – User-define outputs • CERN SWAN service – SWAN notebook good for data analysis and documentation – Use python packages for data analysis • Bokeh • Holoviews…. 7 The WARP Code and Recent Simulation Results • WARP built-in functions to produce run time figures – cgm output figures • Density • Transverse and longitudinal fields

In Today’s Lecture • WARP: Computer-related Issues – Code Installation – WARP Input Script – Data Analysis • Simulation of Self-modulation Instability with WARP • Conclusion 8 The WARP Code and Recent Simulation Results

Self-Modulation Instability (SMI) • What is SMI? 9 – A long proton bunch interacting with plasma generates a wake inside its body which modulates the bunch itself. – Predicted in simulation: – Also observed in the AWAKE experiment N. Kumar et al, PRL 104 255003 (2010) The WARP Code and Recent Simulation Results

Perform Simulation with WARP • Assumptions – Parameters are nearly similar to those of the AWAKE • Simulation parametes – Plasma n = 2. e 14 /cm 3 Dimension: 1. 4 mm * 12 m – Uniform plasma density – Proton beam: – A hyperbolic proton beam in longitudinal/transverse direction – The beam is cut in half to initialize SMI. 10 The WARP Code and Recent Simulation Results n = 1. 22 e 12 /cm 3 Dimension = 0. 17 mm * 2 cm

Simulation Results: 2 D Planar 11 The WARP Code and Recent Simulation Results

Simulation Results: 2 D Planar 12 The WARP Code and Recent Simulation Results

Simulation Results: 2 D Planar 13 The WARP Code and Recent Simulation Results

Simulation Results: 2 D Cylindrical 14 The WARP Code and Recent Simulation Results

In Today’s Lecture • WARP: Computer-related Issues – Code Installation – WARP Input Script – Data Analysis • Simulation of Self-modulation Instability with WARP • Conclusion 15 The WARP Code and Recent Simulation Results

Conclusion • • • The WARP code can be a good tool for AWAKE simulation. The code should be benchmarked with other codes like LCODE. It needs some extra works to improve simulation: – Computer-related works about WARP: • • Study WARP python package and make use of full WARP capabilities Run WARP on HPC cluster – Data analysis: • • Analyze data and Improve output figure qualities User-define functions for outputs – More realistic simulation • • 16 Parameters closer to those of AWAKE 3 D Simulation Add electron-injection Add pre-plasma effect The WARP Code and Recent Simulation Results

Thank you 17 The WARP Code and Recent Simulation Results