Add app IOTA lens example.

examples/iota_lens/input_iotalens_sdep.in

@@ -0,0 +1,109 @@
+###############################################################################
+# Particle Beam(s)
+###############################################################################
+beam.npart = 10000
+beam.units = static
+beam.kin_energy = 2.5
+beam.charge = 1.0e-9
+beam.particle = proton
+beam.distribution = waterbag
+#beam.sigmaX = 2.0e-3
+#beam.sigmaY = 2.0e-3
+#beam.sigmaT = 1.0e-3
+#beam.sigmaPx = 3.0e-4
+#beam.sigmaPy = 3.0e-4
+#beam.sigmaPt = 0.0
+#beam.muxpx = 0.0
+#beam.muypy = 0.0
+#beam.mutpt = 0.0
+beam.sigmaX = 1.397456296195e-003
+beam.sigmaY = 1.397456296195e-003
+beam.sigmaT = 1.0e-4
+beam.sigmaPx = 1.256184325020e-003
+beam.sigmaPy = 1.256184325020e-003
+beam.sigmaPt = 0.0
+beam.muxpx = 0.8090169943749474
+beam.muypy = 0.8090169943749474
+beam.mutpt = 0.0
+
+
+###############################################################################
+# Beamline: lattice elements and segments
+###############################################################################
+lattice.elements = monitor lens const monitor
+
+lens.type = line
+lens.elements = = dr_end nll1 dr nll2 dr nll3 dr nll4 dr nll5 dr nll6  \
+                       dr nll7 dr nll8 dr nll9 dr nll9 dr nll8 dr nll7  \
+                       dr nll6 dr nll5 dr nll4 dr nll3 dr nll2 dr nll1  \
+                       dr_end
+
+# Nonlinear lens segments
+nll1.type = nonlinear_lens
+nll1.knll = 2.2742558121e-6
+nll1.cnll = 0.013262040169952
+
+nll2.type = nonlinear_lens
+nll2.knll = 2.641786366e-6
+nll2.cnll = 0.012304986694423
+
+nll3.type = nonlinear_lens
+nll3.knll = 3.076868353e-6
+nll3.cnll = 0.011401855643727
+
+nll4.type = nonlinear_lens
+nll4.knll = 3.582606522e-6
+nll4.cnll = 0.010566482535866
+
+nll5.type = nonlinear_lens
+nll5.knll = 4.151211157e-6
+nll5.cnll = 0.009816181575902
+
+nll6.type = nonlinear_lens
+nll6.knll = 4.754946985e-6
+nll6.cnll = 0.0091718544892154
+
+nll7.type = nonlinear_lens
+nll7.knll = 5.337102374e-6
+nll7.cnll = 0.008657195579489
+
+nll8.type = nonlinear_lens
+nll8.knll = 5.811437818e-6
+nll8.cnll = 0.008296371635942
+
+nll9.type = nonlinear_lens
+nll9.knll = 6.081693334e-6
+nll9.cnll = 0.008109941789663
+
+dr.type = drift
+dr.ds = 0.1
+
+dr_end.type = drift
+dr_end.ds = 0.05
+
+# Focusing of the external lattice
+const.type = constf
+const.ds = 1.0e-8
+const.kx = 12060.113295833
+const.ky = 12060.113295833
+const.kt = 1.0e-12
+const.nslice = 1
+
+# Beam Monitor: Diagnostics
+monitor.type = beam_monitor
+monitor.backend = h5
+
+###############################################################################
+# Algorithms
+###############################################################################
+algo.particle_shape = 2
+algo.space_charge = false
+
+
+###############################################################################
+# Diagnostics
+###############################################################################
+diag.alpha = 1.376381920471173
+diag.beta = 1.892632003628881
+diag.tn = 0.4
+diag.cn = 0.01

examples/iota_lens/run_iotalens_sdep.py

@@ -33,15 +33,34 @@
 
 #   particle bunch
 distr = distribution.Waterbag(
-    sigmaX=2.0e-3,
-    sigmaY=2.0e-3,
-    sigmaT=1.0e-3,
-    sigmaPx=3.0e-4,
-    sigmaPy=3.0e-4,
+    sigmaX=1.397456296195e-003,
+    sigmaY=1.397456296195e-003,
+    sigmaT=1.0e-4,
+    sigmaPx=1.256184325020e-003,
+    sigmaPy=1.256184325020e-003,
     sigmaPt=0.0,
+    muxpx=0.8090169943749474,
+    muypy=0.8090169943749474,
+    mutpt=0.0,
 )
+#distr = distribution.Waterbag(
+#    sigmaX=1.865379469388e-003,
+#    sigmaY=2.0192133150418e-003,
+#    sigmaT=1.0e-4,
+#    sigmaPx=1.402566720991e-003,
+#    sigmaPy=9.57593913381e-004,
+#    sigmaPt=0.0,
+#    muxpx=-0.482260919078473,
+#    muypy=-0.762127656873158,
+#    mutpt=0.0,
+#)
+
 sim.add_particles(bunch_charge_C, distr, npart)
 
+# add beam diagnostics
+monitor = elements.BeamMonitor("monitor", backend="h5")
+sim.lattice.append(monitor)
+
 # defining parameters of the nonlinear lens
 lens_length = 1.8
 num_lenses = 18
@@ -57,13 +76,24 @@
 # define the nonlinear lens segments
 for j in range(0, num_lenses):
     s = -lens_length / 2.0 + ds_half + j * ds
-    beta = 1.0 + 4.0 * s**2 * math.tan(math.pi * tune_advance) ** 2 / lens_length**2
+    beta_star = lens_length/2.0 * 1.0/math.tan(math.pi * tune_advance)
+   # beta = beta_star * (1.0 + 4.0 * s**2 * math.tan(math.pi * tune_advance) ** 2 / lens_length**2)
+    beta = beta_star * (1.0 + (2.0 * s * math.tan(math.pi * tune_advance) / lens_length)**2)
     knll_s = t_strength * c_parameter**2 * ds / beta
     cnll_s = c_parameter * math.sqrt(beta)
     nllens = elements.NonlinearLens(knll=knll_s, cnll=cnll_s)
     segments = [dr, nllens, dr]
+#    segments = [dr, dr]
     sim.lattice.extend(segments)
 
+# focusing lens
+const = elements.ConstF(ds=1.0e-8, kx=12060.113295833, ky=12060.113295833, kt=1.0e-12, nslice=1)
+sim.lattice.append(const)
+sim.lattice.append(monitor)
+
+# number of periods
+sim.periods = 1
+
 # run simulation
 sim.evolve()
 

src/particles/diagnostics/NonlinearLensInvariants.H

@@ -82,8 +82,8 @@ namespace impactx::diagnostics
             // convert transverse phase space coordinates to normalized units
             amrex::ParticleReal const xn = x/(m_cn*sqrt(m_beta));
             amrex::ParticleReal const yn = y/(m_cn*sqrt(m_beta));
-            amrex::ParticleReal const pxn = px*sqrt(m_beta)/m_cn + m_alpha*x;
-            amrex::ParticleReal const pyn = py*sqrt(m_beta)/m_cn + m_alpha*y;
+            amrex::ParticleReal const pxn = px*sqrt(m_beta)/m_cn + m_alpha*xn;
+            amrex::ParticleReal const pyn = py*sqrt(m_beta)/m_cn + m_alpha*yn;
 
             // assign complex position zeta = x + iy
             Complex const zeta(xn, yn);