v0.4.0

This new release brings Wake-T to version 0.4.0. The main focus is on the new 2d quasistatic wakefield model from P. Baxevanis and G. Stupakov, which greatly expands the capabilities of Wake-T.

This model allows for the accurate calculation of plasma wakefields in the blowout and strongly non-linear regimes, which were not previously accessible (due to limitations of the 1d non-linear fluid model). It can also compute the wakefieds from the witness beam (and not only the driver), meaning that beam-loading effects are now fully taken into account.

With respect to the original publication by Baxevanis and Stupakov, the model has here been extended to include laser-driven wakefields. In addition, it can now also compute the beam wakefields from full particle distributions and not just from analytical gaussian beam expressions.

A comparison between the wakefields as obtained from FBPIC simulations with the new quasistatic model in Wake-T can be seen below.

Changelog

• New quasistatic wakefield model added. Can be used by specifying wakefield_model='quasistatic_2d' in the PlasmaStage, PlasmaRamp and PlasmaLens elements.
• Added beam wakefields to PlasmaLens. For this, a new class CombinedWakefield has been implemented.
• Beam loading effects can now also be taken into account in cold_fluid_1d model by setting beam_wakefields=True in PlasmaStage and PlasmaRamp elements.
• Simulations with no laser (i.e. with only a particle beam) can now be performed.
• Increased performance of Runge-Kutta solver by using numba for some calculations.
• Changed from RegularGridInterpolator to faster interpolation with RectBivariateSpline.
• Changed to a much faster way of computing the sin and cos of the particle theta in cylindrical coordinates.
• Changed driver keyword to laser for the wakefield models.
• Updated existing example and created new one for quasistatic model.
• Updated README.md to remove beam-loading limitation.
• Added numba as requirement.
• Wake-T is now installed as part of the CI tests.
• Removed gamma input parameter from Wakefield methods.
• Increase version to number to 0.4.0.

v0.3.0

This release focuses on consolidating and uniformizing the structure of the beamline elements and adds a 1D CSR model.

Changelog:

• Drifts are now also tracked using transfer matrices up to order 2.
• The properties of all elements are now set in the constructor. For the plasma stages this now includes the tracking mode (analytical or numerical) as well as the wakefield model used.
• All elements now feature a single track method. Previously different elements had different, or even several tracking methods.
• A Beamline class has been added which simplifies particle tracking along several elements.
• The implementation of second-order tracking is now significantly more efficient.
• A 1D CSR model has been added. It is based on an adapted and streamlined version of the 1D model found in Ocelot. A sample simulation for a 1 nC beam after a chicane is shown below:

• Several bug fixes and other internal changes.

v0.2.4

Version used for PhD thesis studies.