Bmad interface¶

PyTao, based on Bmad, can be used to create an Impact-T lattice. This is a simple example of a FODO lattice in Bmad, converted to Impact-T.

In [1]:

from pytao import Tao
from impact import Impact
import matplotlib.pyplot as plt

from pytao import Tao from impact import Impact import matplotlib.pyplot as plt

Bmad lattice¶

In [2]:

LAT = """
no_digested
beginning[beta_a] = 10
beginning[beta_b] = 10
beginning[e_tot] = 10e6
parameter[particle] = electron
parameter[geometry] = open

d1: drift, L = 1
d2: d1
qf: quad, L = 0.1, k1 = 1
qd: qf, k1 = -1

fodo: line = (d1, qf, d2, qd)

lat: line = (2*fodo)

use, lat

"""
LATFILE = "lat.bmad"
with open(LATFILE, "w") as f:
    f.write(LAT)

LAT = """ no_digested beginning[beta_a] = 10 beginning[beta_b] = 10 beginning[e_tot] = 10e6 parameter[particle] = electron parameter[geometry] = open d1: drift, L = 1 d2: d1 qf: quad, L = 0.1, k1 = 1 qd: qf, k1 = -1 fodo: line = (d1, qf, d2, qd) lat: line = (2*fodo) use, lat """ LATFILE = "lat.bmad" with open(LATFILE, "w") as f: f.write(LAT)

In [3]:

tao = Tao(f"-lat {LATFILE} -noplot")
tao.cmd("set particle_start x = 1e-3")

tao = Tao(f"-lat {LATFILE} -noplot") tao.cmd("set particle_start x = 1e-3")

Out[3]:

[]

Impact-T from Bmad¶

In [4]:

I = Impact.from_tao(tao)

I.track1(x0=1e-3, pz0=10e6)

I = Impact.from_tao(tao) I.track1(x0=1e-3, pz0=10e6)

Out[4]:

<ParticleGroup with 1 particles at 0x7fa5d5bb8c80>

In [5]:

I.plot("mean_x", include_labels=True)

I.plot("mean_x", include_labels=True)

Compare¶

In [6]:

s1 = tao.lat_list("*", "ele.s")
x1 = tao.lat_list("*", "orbit.vec.1")

z2 = I.stat("mean_z")
x2 = I.stat("mean_x")

fix, ax = plt.subplots()
ax.plot(s1, x1 * 1e3, marker=".", label="Bmad")
ax.plot(z2, x2 * 1e3, label="Impact-T")
plt.legend()
ax.set_xlabel(r"$z$ (m)")
ax.set_ylabel(r"$x$ (mm)")

s1 = tao.lat_list("*", "ele.s") x1 = tao.lat_list("*", "orbit.vec.1") z2 = I.stat("mean_z") x2 = I.stat("mean_x") fix, ax = plt.subplots() ax.plot(s1, x1 * 1e3, marker=".", label="Bmad") ax.plot(z2, x2 * 1e3, label="Impact-T") plt.legend() ax.set_xlabel(r"$z$ (m)") ax.set_ylabel(r"$x$ (mm)")

Out[6]:

Text(0, 0.5, '$x$ (mm)')

Cleanup¶

In [7]:

import os

os.remove("lat.bmad")

import os os.remove("lat.bmad")