def make_beam(bm):
parts0 = np.zeros((6, bm['Np']))
parts0[0] = bm['Rx'] * np.random.randn(bm['Np'])
parts0[1] = bm['Ox'] * np.random.randn(bm['Np'])
parts0[2] = bm['Ry'] * np.random.randn(bm['Np'])
parts0[3] = bm['Oy'] * np.random.randn(bm['Np'])
parts0[4] = bm['Lz'] * np.random.randn(bm['Np'])
parts0[5] = bm['dE'] * np.random.randn(bm['Np'])
p_array_init = oclt.ParticleArray()
p_array_init.particles = parts0.T.flatten()
p_array_init.E = bm['E']
p_array_init.s = 0.0
if 'Q' in bm:
p_array_init.q_array = (bm['Q'] / bm['Np']) * np.ones(bm['Np'])
else:
p_array_init.q_array = np.ones(bm['Np'])
return p_array_init
def make_beam(bm):
"""
Makes a beam with Gaussian phase distributions
Parameters
----------
bm : dictionary
beam input parameters (in SI units):
Np -- full number of particles
Lz, Rx, Ry -- spatial dimensions of the beam
dE, Ox, Oy -- normalized momenta dispersions
E -- beam mean energy (in GeV)
Q -- full beam charge (in C)
Returns
-------
p_array : an oclt.ParticleArray object
"""
p_array = oclt.ParticleArray(n=bm['Np'])
if 'Features' not in bm:
bm['Features'] = {}
if 'RandomSeed' not in bm['Features']:
bm['Features']['RandomSeed'] = int(np.random.rand()*1e7)
rnd = np.random.RandomState(seed = bm['Features']['RandomSeed'])
if 'X0' not in bm: bm['X0'] = 0.
if 'Y0' not in bm: bm['Y0'] = 0.
if 'Z0' not in bm: bm['Z0'] = 0.
parts0 = np.zeros((6, bm['Np']))
if 'FlatX' in bm['Features']:
parts0[0] = bm['X0'] + bm['Rx']*(2*rnd.rand(bm['Np'])-1)
else:
parts0[0] = bm['X0'] + bm['Rx']*rnd.randn(bm['Np'])
if 'FlatY' in bm['Features']:
parts0[2] = bm['Y0'] + bm['Ry']*(2*rnd.rand(bm['Np'])-1)
else:
parts0[2] = bm['Y0'] + bm['Ry']*rnd.randn(bm['Np'])
if 'FlatZ' in bm['Features']:
parts0[4] = bm['Z0'] + bm['Lz']*(2*rnd.rand(bm['Np'])-1)
else:
parts0[4] = bm['Z0'] + bm['Lz']*rnd.randn(bm['Np'])
parts0[1] = bm['Ox'] * rnd.randn(bm['Np'])
parts0[3] = bm['Oy'] * rnd.randn(bm['Np'])
parts0[5] = bm['dE'] * rnd.randn(bm['Np'])
p_array.rparticles = parts0 #.T.flatten()
p_array.E = bm['E']
p_array.s = 0.0
p_array.x_c = 0.0
p_array.y_c = 0.0
p_array.z_c = 0.0
if 'Q' in bm:
p_array.q_array = (bm['Q']/bm['Np']) * np.ones(bm['Np'])
else:
p_array.q_array = np.ones(bm['Np'])
return p_array
def make_beam_contin(bm, div_chirp=None):
"""
Makes a beam with Gaussian phase distributions,
except for energy spread which is flat-top
Parameters
----------
bm : dictionary
beam input parameters as in make_beam except for:
bm['E'] = (E1,E2) -- range of electron energies (in GeV)
Returns
-------
p_array : an oclt.ParticleArray object
See Also
--------
make_beam
"""
p_array = oclt.ParticleArray()
if 'Features' not in bm:
bm['Features'] = {}
if 'RandomSeed' not in bm['Features']:
bm['Features']['RandomSeed'] = int(np.random.rand()*1e7)
rnd = np.random.RandomState(seed=bm['Features']['RandomSeed'])
E1 = bm['E'][0]
E2 = bm['E'][1]
dE = (E2-E1) / (E2+E1)
p_array.E = 0.5 * (E2+E1)
if 'X0' not in bm: bm['X0'] = 0.
if 'Y0' not in bm: bm['Y0'] = 0.
if 'Z0' not in bm: bm['Z0'] = 0.
parts0 = np.zeros((6, bm['Np']))
if 'FlatX' in bm['Features']:
parts0[0] = bm['X0'] + bm['Rx']*(2*rnd.rand(bm['Np'])-1)
else:
parts0[0] = bm['X0'] + bm['Rx']*rnd.randn(bm['Np'])
if 'FlatY' in bm['Features']:
parts0[2] = bm['Y0'] + bm['Ry']*(2*rnd.rand(bm['Np'])-1)
else:
parts0[2] = bm['Y0'] + bm['Ry']*rnd.randn(bm['Np'])
if 'FlatZ' in bm['Features']:
parts0[4] = bm['Z0'] + bm['Lz']*(2*rnd.rand(bm['Np'])-1)
else:
parts0[4] = bm['Z0'] + bm['Lz']*rnd.randn(bm['Np'])
parts0[5] = dE * (2*rnd.rand(bm['Np'])-1)
if div_chirp != None:
pz0 = np.sqrt( (div_chirp/mc2_GeV)**2-1. )
pz = (p_array.E/mc2_GeV) * (1+parts0[5])
# px = bm['Ox']*pz0*rnd.randn(bm['Np'])
# py = bm['Oy']*pz0*rnd.randn(bm['Np'])
parts0[1] = bm['Ox'] * rnd.randn(bm['Np']) * (pz0/pz)**0.75
parts0[3] = bm['Oy'] * rnd.randn(bm['Np']) * (pz0/pz)**0.75
else:
parts0[1] = bm['Ox'] * rnd.randn(bm['Np'])
parts0[3] = bm['Oy'] * rnd.randn(bm['Np'])
p_array.rparticles = parts0 #.T.flatten()
p_array.s = 0.0
if 'Q' in bm:
p_array.q_array = (bm['Q']/bm['Np']) * np.ones(bm['Np'])
else:
p_array.q_array = np.ones(bm['Np'])
p_array.x_c = 0.0
p_array.y_c = 0.0
p_array.z_c = 0.0
return p_array