Examples

Download notebookView on GitHubRun when the site was built.

Jupyter notebooks in this section are executed when the documentation is built. Download a notebook from its page to run it yourself.

• Optimising an einzel lens finds the voltage, gap and aperture of an einzel lens with beamtracer.optimization, against a scan and the thin-lens estimate.
• Optimising a negative-ion beamlet searches the extraction voltage, the EG aperture and the PG-EG gap of an H⁻ beamlet for the smallest divergence, on a coarse mesh checked against the example’s.
• The duct traces the neutrals from the end of the traced region through the duct to the port with beamtracer.beamline: the walls hit, the footprint at the port, the reionization in the duct gas, against the closed forms.
• The grid turns a beamlet traced in 2D into 3D markers with beamline.beamlet_markers and copies it over an aperture grid with its aiming (ApertureGrid): the footprints of a flat and a curved grid along the beamline.
• The dump pushes the ions left after the neutralizer through the residual-ion dump onto its plates with beamline.FieldRegion, and bends the ions reionized in the duct onto its walls in the stray field.
• The calorimeter records the power map of a beamlet group on a calorimeter with beamline.Calorimeter and infers the beam’s width and divergence from it as the experiments do, against the markers’ own divergence.
• The beamline puts the pieces of beamtracer.beamline in a row, from an aimed group of beamlets through the dump and the duct to the port: where the power goes, the footprint at the port, and the neutral markers handed on to freeofcharge.
• Scripts are complete Python scripts with their plots.
• Building the docs explains how to add an example and control its output.

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  Einzel lens optimisation

  A first design optimisation with beamtracer.optimization: an einzel lens focusing a 30 keV proton beam onto a plane downstream. The optimisation core only calls an evaluation function, here a…

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  Negative-ion beamlet optimisation

  The second problem of beamtracer.optimization, after the einzel lens: one round H^- beamlet extracted from a plasma, solved with BeamOptics and NegativeExtractionPlasma (the beamlet of the example…

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  Duct

  Beyond the accelerator and the neutralizer no field acts on the neutrals: they fly on straight lines to the port. beamtracer.beamline.Duct intersects each line with the duct walls, given as…

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  Grid

  BeamOptics traces one beamlet, in 2D: a round aperture in cylindrical (x, r) geometry, where each trajectory stands for a ring, or a slit in planar geometry. The beamline needs the whole beam in 3D.…

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  Dump

  After the neutralizer the beam still carries ions: D^- that were not stripped and D^+ that were stripped twice. The residual-ion dump deflects them out of the beam onto its plates, biased against…

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  Calorimeter

  In a test facility the beam ends on a calorimeter: a plate of tiles whose temperature rise gives the power on each. From the map the experiments infer the beam's width (a Gaussian fit of the…

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  Beamline

  The pieces of beamtracer.beamline in a row, from the grid to the port: a group of aimed beamlets, the charge states the neutralizer leaves, the residual-ion dump, the duct with its gas and the stray…