diff --git a/Examples/Physics_applications/laser_acceleration/README.rst b/Examples/Physics_applications/laser_acceleration/README.rst index 737cb1fe677..0ba3b5382f2 100644 --- a/Examples/Physics_applications/laser_acceleration/README.rst +++ b/Examples/Physics_applications/laser_acceleration/README.rst @@ -5,8 +5,9 @@ Laser-Wakefield Acceleration of Electrons This example shows how to model a laser-wakefield accelerator (LWFA) :cite:p:`ex-TajimaDawson1982,ex-Esarey1996`. -Laser-wakefield acceleration is best performed in 3D and quasi-cylindrical (RZ) geometry, which ensures that the plasma wavelength of the wakefield is modelled with the right scale lengths. -RZ modeling enables efficient modeling if effects of asymmetry shall be ignored (e.g., asymmetric beams and transverse profiles, hosing of the injected beam, etc.). +Laser-wakefield acceleration is best performed in 3D or quasi-cylindrical (RZ) geometry, in order to correctly capture some of the key physics (laser diffraction, beamloading, shape of the accelerating bubble in the blowout regime, etc.). +For physical situations that have close-to-cylindrical symmetry, simulations in RZ geometry capture the relevant physics at a fraction of the computational cost of a 3D simulation. +On the other hand, for physical situation with strong asymmetries (e.g., non-round laser driver, strong hosing of the accelerated beam, etc.), only 3D simulations are suitable. For LWFA scenarios with long propagation lengths, use the :ref:`boosted frame method `. An example can be seen in the :ref:`PWFA example `. diff --git a/Examples/Physics_applications/plasma_acceleration/README.rst b/Examples/Physics_applications/plasma_acceleration/README.rst index d5605dd93ef..d5775e93aa8 100644 --- a/Examples/Physics_applications/plasma_acceleration/README.rst +++ b/Examples/Physics_applications/plasma_acceleration/README.rst @@ -5,8 +5,9 @@ Beam-Driven Wakefield Acceleration of Electrons This example shows how to model a beam-driven plasma-wakefield accelerator (PWFA) :cite:p:`ex-TajimaDawson1982,ex-Esarey1996`. -PWFA is best performed in 3D and quasi-cylindrical (RZ) geometry, which ensures that the plasma wavelength of the wakefield is modelled with the right scale lengths. -RZ modeling enables efficient modeling if effects of asymmetry shall be ignored (e.g., asymmetric beams and transverse profiles, hosing of the injected beam, etc.). +PWFA is best performed in 3D or quasi-cylindrical (RZ) geometry, in order to correctly capture some of the key physics (structure of the space-charge fields, beamloading, shape of the accelerating bubble in the blowout regime, etc.). +For physical situations that have close-to-cylindrical symmetry, simulations in RZ geometry capture the relevant physics at a fraction of the computational cost of a 3D simulation. +On the other hand, for physical situation with strong asymmetries (e.g., non-round driver, strong hosing of the accelerated beam, etc.), only 3D simulations are suitable. Additionally, to speed up computation, this example uses the :ref:`boosted frame method ` to effectively model long acceleration lengths.