def test_unique_names():
drift_1 = ap.Drift("Drift", length=1)
drift_2 = ap.Drift("Drift", length=2)
with pytest.raises(ap.AmbiguousNameError):
ap.Lattice("Lattice", [drift_1, drift_2])
cell_1 = ap.Lattice("cell", [])
cell_2 = ap.Lattice("cell", [])
with pytest.raises(ap.AmbiguousNameError):
ap.Lattice("Lattice", [cell_1, cell_2])
def test_length_changed():
drift = ap.Drift("Drift", length=1)
cell_1 = ap.Lattice("Cell1", [drift, drift])
cell_2 = ap.Lattice("Cell2", [cell_1, cell_1])
cell_3 = ap.Lattice("Cell3", [cell_2, cell_2])
initial_length = cell_3.length
for i in range(2, 10):
drift.length += 1
print("TEST:", drift.length, cell_3.length)
assert i * initial_length == cell_3.length
def test_quadrupole():
d1 = ap.Drift("D1", length=5)
d2 = ap.Drift("D2", length=0.2)
q = ap.Quadrupole("Q1", length=0.2, k1=1.5)
s = ap.Sextupole("S1", length=0.4, k2=1000)
# s = ap.Drift("S1", length=0.4)
lattice = ap.Lattice("Lattice", [d2, q, d2, s, d1])
distribution = ap.distribution(5,
x_dist="uniform",
x_width=0.0002,
delta_dist="uniform",
delta_width=0.2)
tracking = Tracking(lattice)
s, trajectory = tracking.track(distribution)
_, ax = plt.subplots(figsize=(20, 5))
ax.plot(s, trajectory[:, 0])
plt.ylim(-0.0002, 0.0002)
draw_lattice(lattice, draw_sub_lattices=False)
plt.savefig("/tmp/test_quadrupole.pdf")
"""
Twiss parameter of a FODO lattice
=================================
This example shows how to calulate and plot the Twiss parameter of a FOOD lattice.
"""
#%% Create a fodo based ring
import numpy as np
import apace as ap
D1 = ap.Drift("D1", length=0.55)
d1 = ap.Drift("D1", length=0.55)
b1 = ap.Dipole("B1", length=1.5, angle=0.392701, e1=0.1963505, e2=0.1963505)
q1 = ap.Quadrupole("Q1", length=0.2, k1=1.2)
q2 = ap.Quadrupole("Q2", length=0.4, k1=-1.2)
fodo_cell = ap.Lattice("FODO_CELL", [q1, d1, b1, d1, q2, d1, b1, d1, q1])
fodo_ring = ap.Lattice("FODO_RING", [fodo_cell] * 8)
#%%
# Output some info on the FODO lattice
print(
f"Overview of {fodo_ring.name}",
f"Num of elements: {len(fodo_ring.arrangement)}",
f"Lattice Length : {fodo_ring.length}",
f"Cell Length : {fodo_cell.length}",
sep="\n",
)
#%%
"""
Necktie Plot
============
Plot the lattice stability in dependence of the quadrupole strengths.
"""
#%%
# Create a new FODO lattice
import apace as ap
D1 = ap.Drift("D1", length=0.55)
d1 = ap.Drift("D1", length=0.55)
b1 = ap.Drift("B1", length=1.5)
b1 = ap.Dipole("B1", length=1.5, angle=0.392701, e1=0.1963505, e2=0.1963505)
q1 = ap.Quadrupole("Q1", length=0.2, k1=1.2)
q2 = ap.Quadrupole("Q2", length=0.4, k1=-1.2)
fodo_cell = ap.Lattice("FODO_CELL", [q1, d1, b1, d1, q2, d1, b1, d1, q1])
fodo_ring = ap.Lattice("FODO_RING", [fodo_cell] * 8)
#%%
# Scan the quadrupole strength and record lattice stability
import numpy as np
n_steps = 100
k1_start = 0
k1_end = 2
q1_values = np.linspace(k1_start, k1_end, n_steps)
q2_values = np.linspace(k1_start, -k1_end, n_steps)
stable = np.empty((n_steps, n_steps), dtype=bool)