def get_potential_coefficient():
tp = get_trap_parameters()
omegaRF = 2 * np.pi * tp[2]
A = constants.q ** 2 * tp[1] ** 2 / (tp[3] * omegaRF ** 2 * tp[0] ** 4)
return A
def get_potential_coefficient():
tp = get_trap_parameters()
omegaRF = 2 * np.pi * tp[2]
A = constants.q**2 * tp[1]**2 / (tp[3] * omegaRF**2 * tp[0]**4)
return A
def make_crystal(N_ions=6, starting_ions=None, constant_ion=None,
progress=True, assymetry=None):
'''
This function iterates random steps in postion and recalculates the energy
of the configuration of N ions, if the energy is decreased it accepts
the move and repeats
'''
A = utility.get_potential_coefficient()
tp = get_trap_parameters()
sp = get_simulation_parameters()
if assymetry:
assy = assymetry
else:
assy = tp[4]
pos_spread = sp[2]
iterations = sp[1]
step_size = sp[0]
if progress:
p = ProgressBar(iterations)
N = N_ions
ions = []
if starting_ions is None:
for _i in range(N):
# initiate ions in random position
x0 = (np.random.rand() - 0.5)*pos_spread
y0 = (np.random.rand() - 0.5)*pos_spread
ions.append(ion(x0, y0))
else:
# initiate ions in specified starting positions
for starting_ion in starting_ions:
ions.append(ion(starting_ion.x, starting_ion.y,
starting_ion.color))
E0 = total_energy(ions, assy)
iters = 0
E = [E0]
last_E = E0
if constant_ion is not None:
for fixed in constant_ion:
ions[fixed].constant = True
while iters < iterations:
if progress:
p.animate(iters)
iters += 1
for particle in ions:
if not particle.constant: # Checks if ion is movable
particle.lastx = particle.x
particle.x = particle.x + (np.random.rand() - 0.5)*step_size
particle.lasty = particle.y
particle.y = particle.y + (np.random.rand() - 0.5)*step_size
tot_E = total_energy(ions, assy, A)
if tot_E < last_E: # Check to take the position step or not
E.append(tot_E)
last_E = tot_E
else:
particle.x = particle.lastx
particle.y = particle.lasty
return E[-1], ions
def make_crystal(N_ions=6,
starting_ions=None,
constant_ion=None,
progress=True,
assymetry=None):
'''
This function iterates random steps in postion and recalculates the energy
of the configuration of N ions, if the energy is decreased it accepts
the move and repeats
'''
A = utility.get_potential_coefficient()
tp = get_trap_parameters()
sp = get_simulation_parameters()
if assymetry:
assy = assymetry
else:
assy = tp[4]
pos_spread = sp[2]
iterations = sp[1]
step_size = sp[0]
if progress:
p = ProgressBar(iterations)
N = N_ions
ions = []
if starting_ions is None:
for _i in range(N):
# initiate ions in random position
x0 = (np.random.rand() - 0.5) * pos_spread
y0 = (np.random.rand() - 0.5) * pos_spread
ions.append(ion(x0, y0))
else:
# initiate ions in specified starting positions
for starting_ion in starting_ions:
ions.append(ion(starting_ion.x, starting_ion.y,
starting_ion.color))
E0 = total_energy(ions, assy)
iters = 0
E = [E0]
last_E = E0
if constant_ion is not None:
for fixed in constant_ion:
ions[fixed].constant = True
while iters < iterations:
if progress:
p.animate(iters)
iters += 1
for particle in ions:
if not particle.constant: # Checks if ion is movable
particle.lastx = particle.x
particle.x = particle.x + (np.random.rand() - 0.5) * step_size
particle.lasty = particle.y
particle.y = particle.y + (np.random.rand() - 0.5) * step_size
tot_E = total_energy(ions, assy, A)
if tot_E < last_E: # Check to take the position step or not
E.append(tot_E)
last_E = tot_E
else:
particle.x = particle.lastx
particle.y = particle.lasty
return E[-1], ions
