APEX GunĀ¶
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# Useful for debugging
%load_ext autoreload
%autoreload 2
# Useful for debugging
%load_ext autoreload
%autoreload 2
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import matplotlib.pyplot as plt
import matplotlib
matplotlib.rcParams['figure.figsize'] = (13,8)
%config InlineBackend.figure_format = 'retina'
import matplotlib.pyplot as plt
import matplotlib
matplotlib.rcParams['figure.figsize'] = (13,8)
%config InlineBackend.figure_format = 'retina'
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from astra import Astra
from astra import recommended_spacecharge_mesh
from distgen import Generator
import matplotlib.pyplot as plt
import os
from astra import Astra
from astra import recommended_spacecharge_mesh
from distgen import Generator
import matplotlib.pyplot as plt
import os
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# Input template file
ASTRA_IN = '../templates/apex_gun/astra.in'
DISTGEN_IN = '../templates/apex_gun/distgen.yaml'
# Input template file
ASTRA_IN = '../templates/apex_gun/astra.in'
DISTGEN_IN = '../templates/apex_gun/distgen.yaml'
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recommended_spacecharge_mesh(10000)
recommended_spacecharge_mesh(10000)
Out[5]:
{'nrad': 20, 'nlong_in': 43}
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G = Generator(DISTGEN_IN)
G['n_particle'] = 10000
G.run()
P0 = G.particles
P0.status[:] = -1 # Cathode start
#factor = 2
#P0.x *= factor
#P0.y *= 1/factor
P0.plot('x', 'y')
G = Generator(DISTGEN_IN)
G['n_particle'] = 10000
G.run()
P0 = G.particles
P0.status[:] = -1 # Cathode start
#factor = 2
#P0.x *= factor
#P0.y *= 1/factor
P0.plot('x', 'y')
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# Make an Astra object
A = Astra(input_file=ASTRA_IN, initial_particles=P0, verbose=True)
sc_settings = recommended_spacecharge_mesh(P0['n_particle'])
A.input['charge'].update()
A.input['output']['zstop'] = 0.15
A.input['charge']['lspch'] = True
A.input['charge']['lspch3d'] = False
# Make an Astra object
A = Astra(input_file=ASTRA_IN, initial_particles=P0, verbose=True)
sc_settings = recommended_spacecharge_mesh(P0['n_particle'])
A.input['charge'].update()
A.input['output']['zstop'] = 0.15
A.input['charge']['lspch'] = True
A.input['charge']['lspch3d'] = False
Configured to run in: /var/folders/2f/l5_mybzs30j4qqvyj98w1_nw0000gn/T/tmpkvgt3vpc
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%%time
# Run
A.run()
%%time
# Run
A.run()
Initial particles written to /var/folders/2f/l5_mybzs30j4qqvyj98w1_nw0000gn/T/tmpkvgt3vpc/astra.particles
--------------------------------------------------------------------------
Astra- A space charge tracking algorithm
Version 4.0 - macOS 64bit - Apple Silicon
DESY, Hamburg 2022
Wed Aug 2 08:49:09
Parameter file is: astra.in
APEX Gun
Initialize element settings:
--------------------------------------------------------------------------
Cavity:
Reading cavity field data from: 187MHz_HighDef_March2010.dat
field smoothing is applied
Cavity Frequency f = 0.1870 GHz
maximum gradient 20.00 MV/m
at 0.000 m
estimated average gradient 2.667 MV/m
nominal phase 0.000 deg
--------------------------------------------------------------------------
Solenoid:
Reading solenoid field data from: realbucking.dat
field smoothing is applied
maximum |Bz| field 0.000 T
at -6.2050E-02 m
integral Bz squared 0.000 T^2m
Reading solenoid field data from: newSOL.dat
field smoothing is applied
maximum |Bz| field 5.7000E-02 T
at 0.2465 m
integral Bz squared 2.8019E-04 T^2m
solenoids number: 1 and 2 overlap
--------------------------------------------------------------------------
10001 particles from file astra.particles
Cathode located at: z = 0.000 m
Particles taken into account N = 10001
total charge Q = -0.1000 nC
horizontal beam position x = -1.3665E-16 mm
vertical beam position y = -1.6267E-16 mm
longitudinal beam position z = 0.000 m
horizontal beam size sig x = 0.2500 mm
vertical beam size sig y = 0.2500 mm
longitudinal beam size sig z = 0.000 mm
total emission time t = 5.0643E-02 ns
rms emission time sig t = 8.3859E-03 ns
average kinetic energy E = 3.7500E-07 MeV
energy spread dE = 3.0451E-04 keV
average momentum P = 6.1907E-04 MeV/c
transverse beam emittance eps x = 0.1749 pi mrad mm
correlated divergence cor x = -0.5362 mrad
transverse beam emittance eps y = 0.1749 pi mrad mm
correlated divergence cor y = -0.6932 mrad
longitudinal beam emittance eps z = 0.000 pi keV mm
correlated energy spread cor z = 0.000 keV
emittance ratio eps y/eps x = 1.000
--------------------------------------------------------------------------
Start auto phasing:
Scan cavity number : 1
6 unstable trajectories out of 50
--------------------------------------------------------------------------
Start phase scan:
Cavity number : 1 from : 0.000 m to: 0.1990 m
197 unstable trajectories out of 360
Cavity phasing completed:
Cavity number Energy gain [MeV] at Phase [deg]
1 0.7586 261.45
--------------------------------------------------------------------------
on axis tracking of the reference particle:
initial position z = 0.000 m
x = -7.8886E-18 mm
y = -3.9443E-18 mm
initial momentum p = 2.8534E-04 MeV/c
global phase shift phi = 0.000 deg
time step for integration dt = 7.500 ps
--------------------------------------------------------------------------
Online element settings:
--------------------------------------------------------------------------
particle reaches position z = 0.1500 m
time of flight is t = 0.6043 ns
final momentum p = 1.162 MeV/c
final phase (cavity 1) phi_end = 268.4 deg
--------------------------------------------------------------------------
off axis tracking of the reference particle:
initial position z = 0.000 m
x = 0.2500 mm
y = 0.2500 mm
final position x = 0.5436 mm
y = 0.5978 mm
divergence px/pz = 1.865 mrad
py/pz = 3.587 mrad
--------------------------------------------------------------------------
tracking of 10001 particles:
tracking will stop at z = 0.1500 m
space charge forces are INCLUDED
cylindrical symmetric algorithm
mirror charges at the cathode are taken into account
mirror charge switched off at: 0.1138 m
final checkpoint at z = 0.1500 m
total number of iteration steps: 1651
**********************************************************************
Particles taken into account N = 10001
total charge Q = -0.1000 nC
horizontal beam position x = 2.3682E-04 mm
vertical beam position y = -7.5225E-06 mm
longitudinal beam position z = 0.1500 m
horizontal beam size sig x = 2.413 mm
vertical beam size sig y = 2.413 mm
longitudinal beam size sig z = 2.654 mm
average kinetic energy E = 0.7585 MeV
energy spread dE = 3.257 keV
average momentum P = 1.162 MeV/c
transverse beam emittance eps x = 16.97 pi mrad mm
correlated divergence cor x = 15.16 mrad
transverse beam emittance eps y = 16.97 pi mrad mm
correlated divergence cor y = 15.16 mrad
longitudinal beam emittance eps z = 2.417 pi keV mm
correlated energy spread cor z = 3.127 keV
emittance ratio eps y/eps x = 1.000
Particle Statistics:
Total number of particles on stack = 10001
Electrons (total) = 10001
particles at the cathode = 0
active particles = 10001
passive particles (lost out of bunch) = 0
probe particles = 0
backward traveling particles = 0
particles lost with z<Zmin = 0
particles lost due to cathode field = 0
particles lost on aperture = 0
**********************************************************************
Emittance information saved to file : astra.Xemit.001
Emittance information saved to file : astra.Yemit.001
Emittance information saved to file : astra.Zemit.001
Lost & found saved to file : astra.LandF.001
Ref. part. information saved to file : astra.ref.001
Phase-space distributions logged in : astra.Log.001
Phase scan saved to file : astra.PScan.001
Cathode sp. charge field saved to file : astra.Cathode.001
Core emittance data saved to file : astra.Cemit.001
**********************************************************************
finished simulation Wed Aug 2 08:49:31 2023
elapsed time : 22.0 seconds
execution time : 21.9 seconds
system time : 0.1 seconds
Goodbye.
--------------------------------------------------------------------------
loading 1 particle files
[15.0]
{'start_time': 1690991349.348098, 'run_script': '/Users/chrisonian/Code/Astra/bin/Astra astra.in', 'run_time': 22.16491198539734}
CPU times: user 59.4 ms, sys: 10.1 ms, total: 69.5 ms
Wall time: 22.2 s
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P1 = A.particles[-1]
P1.plot('z', 'pz')
P1 = A.particles[-1]
P1.plot('z', 'pz')
3D Space Charge methodĀ¶
This does not properly take the image charge force at the cathode.
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A2 = A.copy()
A2.input['charge']['lspch'] = True
A2.input['charge']['lspch3d'] = True
A2.input['charge']['l2d_3d'] = False
A2.input['charge']['nxf'] = 32
A2.input['charge']['nyf'] = 32
A2.input['charge']['nzf'] = 32
A2.input['charge']['nx0'] = 4
A2.input['charge']['ny0'] = 4
A2.input['charge']['nz0'] = 4
A2.configure()
A2.run()
A2 = A.copy()
A2.input['charge']['lspch'] = True
A2.input['charge']['lspch3d'] = True
A2.input['charge']['l2d_3d'] = False
A2.input['charge']['nxf'] = 32
A2.input['charge']['nyf'] = 32
A2.input['charge']['nzf'] = 32
A2.input['charge']['nx0'] = 4
A2.input['charge']['ny0'] = 4
A2.input['charge']['nz0'] = 4
A2.configure()
A2.run()
Configured to run in: /var/folders/2f/l5_mybzs30j4qqvyj98w1_nw0000gn/T/tmpd93dk5wn
Initial particles written to /var/folders/2f/l5_mybzs30j4qqvyj98w1_nw0000gn/T/tmpd93dk5wn/astra.particles
--------------------------------------------------------------------------
Astra- A space charge tracking algorithm
Version 4.0 - macOS 64bit - Apple Silicon
DESY, Hamburg 2022
Wed Aug 2 08:49:32
Parameter file is: astra.in
APEX Gun
Initialize element settings:
--------------------------------------------------------------------------
Cavity:
Reading cavity field data from: 187MHz_HighDef_March2010.dat
field smoothing is applied
Cavity Frequency f = 0.1870 GHz
maximum gradient 20.00 MV/m
at 0.000 m
estimated average gradient 2.667 MV/m
nominal phase 0.000 deg
--------------------------------------------------------------------------
Solenoid:
Reading solenoid field data from: realbucking.dat
field smoothing is applied
maximum |Bz| field 0.000 T
at -6.2050E-02 m
integral Bz squared 0.000 T^2m
Reading solenoid field data from: newSOL.dat
field smoothing is applied
maximum |Bz| field 5.7000E-02 T
at 0.2465 m
integral Bz squared 2.8019E-04 T^2m
solenoids number: 1 and 2 overlap
--------------------------------------------------------------------------
10001 particles from file astra.particles
Particles taken into account N = 10001
total charge Q = -0.1000 nC
horizontal beam position x = -1.3665E-16 mm
vertical beam position y = -1.6267E-16 mm
longitudinal beam position z = 0.000 m
horizontal beam size sig x = 0.2500 mm
vertical beam size sig y = 0.2500 mm
longitudinal beam size sig z = 0.000 mm
total emission time t = 5.0643E-02 ns
rms emission time sig t = 8.3859E-03 ns
average kinetic energy E = 3.7500E-07 MeV
energy spread dE = 3.0451E-04 keV
average momentum P = 6.1907E-04 MeV/c
transverse beam emittance eps x = 0.1749 pi mrad mm
correlated divergence cor x = -0.5362 mrad
transverse beam emittance eps y = 0.1749 pi mrad mm
correlated divergence cor y = -0.6932 mrad
longitudinal beam emittance eps z = 0.000 pi keV mm
correlated energy spread cor z = 0.000 keV
emittance ratio eps y/eps x = 1.000
--------------------------------------------------------------------------
Start auto phasing:
Scan cavity number : 1
6 unstable trajectories out of 50
--------------------------------------------------------------------------
Start phase scan:
Cavity number : 1 from : 0.000 m to: 0.1990 m
197 unstable trajectories out of 360
Cavity phasing completed:
Cavity number Energy gain [MeV] at Phase [deg]
1 0.7586 261.45
--------------------------------------------------------------------------
on axis tracking of the reference particle:
initial position z = 0.000 m
x = -7.8886E-18 mm
y = -3.9443E-18 mm
initial momentum p = 2.8534E-04 MeV/c
global phase shift phi = 0.000 deg
time step for integration dt = 7.500 ps
--------------------------------------------------------------------------
Online element settings:
--------------------------------------------------------------------------
particle reaches position z = 0.1500 m
time of flight is t = 0.6043 ns
final momentum p = 1.162 MeV/c
final phase (cavity 1) phi_end = 268.4 deg
--------------------------------------------------------------------------
off axis tracking of the reference particle:
initial position z = 0.000 m
x = 0.2500 mm
y = 0.2500 mm
final position x = 0.5436 mm
y = 0.5978 mm
divergence px/pz = 1.865 mrad
py/pz = 3.587 mrad
--------------------------------------------------------------------------
tracking of 10001 particles:
tracking will stop at z = 0.1500 m
space charge forces are INCLUDED
3D FFT algorithm
WARNING: particle outside grid
WARNING: particle outside grid
WARNING: particle outside grid
WARNING: particle outside grid
final checkpoint at z = 0.1500 m
total number of iteration steps: 1651
**********************************************************************
Particles taken into account N = 10001
total charge Q = -0.1000 nC
horizontal beam position x = -1.8560E-04 mm
vertical beam position y = -1.5354E-04 mm
longitudinal beam position z = 0.1500 m
horizontal beam size sig x = 2.972 mm
vertical beam size sig y = 2.973 mm
longitudinal beam size sig z = 2.571 mm
average kinetic energy E = 0.7596 MeV
energy spread dE = 3.174 keV
average momentum P = 1.163 MeV/c
transverse beam emittance eps x = 25.77 pi mrad mm
correlated divergence cor x = 18.53 mrad
transverse beam emittance eps y = 25.77 pi mrad mm
correlated divergence cor y = 18.54 mrad
longitudinal beam emittance eps z = 2.345 pi keV mm
correlated energy spread cor z = 3.040 keV
emittance ratio eps y/eps x = 0.9999
Particle Statistics:
Total number of particles on stack = 10001
Electrons (total) = 10001
particles at the cathode = 0
active particles = 10001
passive particles (lost out of bunch) = 0
probe particles = 0
backward traveling particles = 0
particles lost with z<Zmin = 0
particles lost due to cathode field = 0
particles lost on aperture = 0
**********************************************************************
Emittance information saved to file : astra.Xemit.001
Emittance information saved to file : astra.Yemit.001
Emittance information saved to file : astra.Zemit.001
Lost & found saved to file : astra.LandF.001
Ref. part. information saved to file : astra.ref.001
Phase-space distributions logged in : astra.Log.001
Phase scan saved to file : astra.PScan.001
Cathode sp. charge field saved to file : astra.Cathode.001
Core emittance data saved to file : astra.Cemit.001
**********************************************************************
finished simulation Wed Aug 2 08:50:07 2023
elapsed time : 35.6 seconds
execution time : 35.4 seconds
system time : 0.2 seconds
Goodbye.
--------------------------------------------------------------------------
loading 1 particle files
[15.0]
{'start_time': 1690991372.058728, 'run_script': '/Users/chrisonian/Code/Astra/bin/Astra astra.in', 'run_time': 35.72111988067627}
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P2 = A2.particles[-1]
P2.plot('x', 'px')
P2 = A2.particles[-1]
P2.plot('x', 'px')
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k1 = 'z'
k2 = 'x'
plt.scatter(P2[k1], P2[k2], label='3d', marker='.')
plt.scatter(P1[k1], P1[k2], label='2d', marker='x')
plt.legend()
k1 = 'z'
k2 = 'x'
plt.scatter(P2[k1], P2[k2], label='3d', marker='.')
plt.scatter(P1[k1], P1[k2], label='2d', marker='x')
plt.legend()
Out[12]:
<matplotlib.legend.Legend at 0x15c80cf70>
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k1 = 'x'
k2 = 'y'
units1 = str(A.units(k1))
units2 = str(A.units(k2))
plt.xlabel(k1+f' ({units1})')
plt.ylabel(k2+f' ({units2})')
plt.scatter(P2[k1], P2[k2], label='Astra 3d', marker='.')
plt.scatter(P1[k1], P1[k2], label='Astra 2d', marker='.')
#plt.scatter(P3[k1], P3[k2], label='Impact-T 3d', marker='.')
#plt.scatter(P4[k1], P4[k2], label='GPT 3D', marker='.')
plt.legend()
k1 = 'x'
k2 = 'y'
units1 = str(A.units(k1))
units2 = str(A.units(k2))
plt.xlabel(k1+f' ({units1})')
plt.ylabel(k2+f' ({units2})')
plt.scatter(P2[k1], P2[k2], label='Astra 3d', marker='.')
plt.scatter(P1[k1], P1[k2], label='Astra 2d', marker='.')
#plt.scatter(P3[k1], P3[k2], label='Impact-T 3d', marker='.')
#plt.scatter(P4[k1], P4[k2], label='GPT 3D', marker='.')
plt.legend()
Out[13]:
<matplotlib.legend.Legend at 0x15d596580>
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k1 = 'z'
k2 = 'pz'
units1 = str(A.units(k1))
units2 = str(A.units(k2))
plt.xlabel(k1+f' ({units1})')
plt.ylabel(k2+f' ({units2})')
plt.scatter(P2[k1], P2[k2], label='Astra 3d', marker='.')
plt.scatter(P1[k1], P1[k2], label='Astra 2d', marker='.')
#plt.scatter(P3[k1], P3[k2], label='Impact-T 3d', marker='.')
#plt.scatter(P4[k1], P4[k2], label='GPT 3D', marker='.')
plt.legend()
k1 = 'z'
k2 = 'pz'
units1 = str(A.units(k1))
units2 = str(A.units(k2))
plt.xlabel(k1+f' ({units1})')
plt.ylabel(k2+f' ({units2})')
plt.scatter(P2[k1], P2[k2], label='Astra 3d', marker='.')
plt.scatter(P1[k1], P1[k2], label='Astra 2d', marker='.')
#plt.scatter(P3[k1], P3[k2], label='Impact-T 3d', marker='.')
#plt.scatter(P4[k1], P4[k2], label='GPT 3D', marker='.')
plt.legend()
Out[14]:
<matplotlib.legend.Legend at 0x15f0fa7f0>
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P1.plot('z', 'pz')
P1.plot('z', 'pz')
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P2.plot('z', 'pz')
P2.plot('z', 'pz')
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A.input['output']
A.input['output']
Out[17]:
{'zstart': 0,
'zstop': 0.15,
'zemit': 1000,
'zphase': 1,
'screen(1)': 1.490314,
'lmagnetized': True,
'lsub_rot': False,
'lproject_emit': False,
'larmors': False,
'emits': True,
'c_emits': True,
'landfs': True,
'phases': True,
'tracks': True,
'refs': True,
'tchecks': False,
'cathodes': True,
'high_res': True}