Add Python equivs for thermal tests.

examples/epac2004_benchmarks/run_bithermal.py

@@ -0,0 +1,64 @@
+#!/usr/bin/env python3
+#
+# Copyright 2022-2023 ImpactX contributors
+# Authors: Marco Garten, Axel Huebl, Chad Mitchell
+# License: BSD-3-Clause-LBNL
+#
+# -*- coding: utf-8 -*-
+
+import amrex.space3d as amr
+from impactx import ImpactX, RefPart, distribution, elements
+
+sim = ImpactX()
+
+# set numerical parameters and IO control
+sim.n_cell = [56, 56, 64]
+sim.particle_shape = 2  # B-spline order
+sim.space_charge = True
+sim.dynamic_size = True
+sim.prob_relative = 4.0
+
+# beam diagnostics
+sim.slice_step_diagnostics = False
+
+# domain decomposition & space charge mesh
+sim.init_grids()
+
+# beam parameters
+energy_MeV = 0.1  # reference energy
+bunch_charge_C = 1.4285714285714285714e-10  # used with space charge
+npart = 10000  # number of macro particles
+
+#   reference particle
+ref = sim.particle_container().ref_particle()
+ref.set_charge_qe(1.0).set_mass_MeV(938.27208816).set_energy_MeV(energy_MeV)
+
+#   particle bunch
+distr = distribution.Bithermal(
+    k=6.283185307179586,
+    kT=36.0e-6,
+    kT_halo=900.0e-6,
+    normalize=0.54226,
+    normalize_halo=0.08195,
+    w_halo=0.05,
+)
+sim.add_particles(bunch_charge_C, distr, npart)
+
+# add beam diagnostics
+monitor = elements.BeamMonitor("monitor", backend="h5")
+
+# design the accelerator lattice
+sim.lattice.append(monitor)
+
+constf = elements.Constf(ds=10.0, kx=6.283185307179586,
+                         ky=6.283185307179586,kt=6.283185307179586,nslice=400)
+
+sim.lattice.append(constf)
+sim.lattice.append(monitor)
+
+# run simulation
+sim.evolve()
+
+# clean shutdown
+del sim
+amr.finalize()

examples/epac2004_benchmarks/run_thermal.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+#
+# Copyright 2022-2023 ImpactX contributors
+# Authors: Marco Garten, Axel Huebl, Chad Mitchell
+# License: BSD-3-Clause-LBNL
+#
+# -*- coding: utf-8 -*-
+
+import amrex.space3d as amr
+from impactx import ImpactX, RefPart, distribution, elements
+
+sim = ImpactX()
+
+# set numerical parameters and IO control
+sim.n_cell = [56, 56, 64]
+sim.particle_shape = 2  # B-spline order
+sim.space_charge = True
+sim.dynamic_size = True
+sim.prob_relative = 4.0
+
+# beam diagnostics
+sim.slice_step_diagnostics = False
+
+# domain decomposition & space charge mesh
+sim.init_grids()
+
+# beam parameters
+energy_MeV = 0.1  # reference energy
+bunch_charge_C = 1.4285714285714285714e-10  # used with space charge
+npart = 10000  # number of macro particles
+
+#   reference particle
+ref = sim.particle_container().ref_particle()
+ref.set_charge_qe(1.0).set_mass_MeV(938.27208816).set_energy_MeV(energy_MeV)
+
+#   particle bunch
+distr = distribution.Bithermal(
+    k=6.283185307179586,
+    kT=36.0e-6,
+    kT_halo=36.0e-6,
+    normalize=0.41604661,
+    normalize_halo=0.0,
+    w_halo=0.0,
+)
+sim.add_particles(bunch_charge_C, distr, npart)
+
+# add beam diagnostics
+monitor = elements.BeamMonitor("monitor", backend="h5")
+
+# design the accelerator lattice
+sim.lattice.append(monitor)
+
+constf = elements.Constf(ds=10.0, kx=6.283185307179586,
+                         ky=6.283185307179586,kt=6.283185307179586,nslice=400)
+
+#   set first lattice element
+sim.lattice.append(constf)
+sim.lattice.append(monitor)
+
+# run simulation
+sim.evolve()
+
+# clean shutdown
+del sim
+amr.finalize()

src/python/distribution.cpp

@@ -92,6 +92,17 @@ void init_distribution(py::module& m)
              "A 6D Semi-Gaussian distribution (uniform in position, Gaussian in momentum)."
         );
 
+    py::class_<distribution::Thermal>(md, "Thermal")
+        .def(py::init<
+                 amrex::ParticleReal const, amrex::ParticleReal const, amrex::ParticleReal const,
+                 amrex::ParticleReal const, amrex::ParticleReal const,
+             >(),
+             py::arg("k"), py::arg("kT1"), py::arg("kT2"),
+             py::arg("halo"), py::arg("data"),
+             "A stationary thermal or bithermal distribution\n\n"
+             "R. D. Ryne, J. Qiang, and A. Adelmann, in Proc. EPAC2004, pp. 1942-1944 (2004)"
+        );
+
     py::class_<distribution::Triangle>(md, "Triangle")
         .def(py::init<
                  amrex::ParticleReal const, amrex::ParticleReal const, amrex::ParticleReal const,