def test_vind(self):
# randomly chose omega_c from allowed range
np.random.seed(1980)
factor = np.random.uniform(0.9, 1.1)
# round results to this digits
digit_round = 8
# SPS parameters
C = 2 * np.pi * 1100.009 # Ring circumference [m]
gamma_t = 18.0 # Gamma at transition
alpha = 1 / gamma_t**2 # Momentum compaction factor
p_s = 25.92e9 # Synchronous momentum at injection [eV]
h = 4620 # 200 MHz system harmonic
V = 4.5e6 # 200 MHz RF voltage
phi = 0. # 200 MHz RF phase
# Beam and tracking parameters
N_m = 1e5 # Number of macro-particles for tracking
N_b = 1.0e11 # Bunch intensity [ppb]
N_t = 1 # Number of turns to track
ring = Ring(C, alpha, p_s, Proton(), n_turns=N_t)
rf = RFStation(ring, h, V, phi)
beam = Beam(ring, N_m, N_b)
bigaussian(ring, rf, beam, 3.2e-9 / 4, seed=1234, reinsertion=True)
n_shift = 5 # how many rf-buckets to shift beam
beam.dt += n_shift * rf.t_rf[0, 0]
profile = Profile(beam,
CutOptions=CutOptions(
cut_left=(n_shift - 1.5) * rf.t_rf[0, 0],
cut_right=(n_shift + 1.5) * rf.t_rf[0, 0],
n_slices=140))
profile.track()
l_cav = 16.082
v_g = 0.0946
tau = l_cav / (v_g * c) * (1 + v_g)
TWC_impedance_source = TravelingWaveCavity(l_cav**2 * 27.1e3 / 8,
200.222e6, 2 * np.pi * tau)
# Beam loading by convolution of beam and wake from cavity
inducedVoltageTWC = InducedVoltageTime(beam, profile,
[TWC_impedance_source])
induced_voltage = TotalInducedVoltage(beam, profile,
[inducedVoltageTWC])
induced_voltage.induced_voltage_sum()
V_ind_impSource = np.around(induced_voltage.induced_voltage,
digit_round)
# Beam loading via feed-back system
OTFB_4 = SPSOneTurnFeedback(rf, beam, profile, 4, n_cavities=1)
OTFB_4.counter = 0 # First turn
OTFB_4.omega_c = factor * OTFB_4.TWC.omega_r
# Compute impulse response
OTFB_4.TWC.impulse_response_beam(OTFB_4.omega_c, profile.bin_centers)
# Compute induced voltage in (I,Q) coordinates
OTFB_4.beam_induced_voltage(lpf=False)
# convert back to time
V_ind_OTFB \
= OTFB_4.V_fine_ind_beam.real \
* np.cos(OTFB_4.omega_c*profile.bin_centers) \
+ OTFB_4.V_fine_ind_beam.imag \
* np.sin(OTFB_4.omega_c*profile.bin_centers)
V_ind_OTFB = np.around(V_ind_OTFB, digit_round)
self.assertListEqual(
V_ind_impSource.tolist(),
V_ind_OTFB.tolist(),
msg="In TravelingWaveCavity test_vind: induced voltages differ")
def test_vind(self):
# randomly chose omega_c from allowed range
np.random.seed(1980)
factor = np.random.uniform(0.9, 1.1)
# round results to this digits
digit_round = 8
# SPS parameters
C = 2*np.pi*1100.009 # Ring circumference [m]
gamma_t = 18.0 # Gamma at transition
alpha = 1/gamma_t**2 # Momentum compaction factor
p_s = 25.92e9 # Synchronous momentum at injection [eV]
h = 4620 # 200 MHz system harmonic
V = 4.5e6 # 200 MHz RF voltage
phi = 0. # 200 MHz RF phase
# Beam and tracking parameters
N_m = 1e5 # Number of macro-particles for tracking
N_b = 1.0e11 # Bunch intensity [ppb]
N_t = 1 # Number of turns to track
ring = Ring(C, alpha, p_s, Proton(), n_turns=N_t)
rf = RFStation(ring, h, V, phi)
beam = Beam(ring, N_m, N_b)
bigaussian(ring, rf, beam, 3.2e-9/4, seed=1234, reinsertion=True)
n_shift = 5 # how many rf-buckets to shift beam
beam.dt += n_shift * rf.t_rf[0,0]
profile = Profile(beam, CutOptions=
CutOptions(cut_left=(n_shift-1.5)*rf.t_rf[0,0],
cut_right=(n_shift+1.5)*rf.t_rf[0,0],
n_slices=140))
profile.track()
l_cav = 16.082
v_g = 0.0946
tau = l_cav/(v_g*c)*(1 + v_g)
TWC_impedance_source = TravelingWaveCavity(l_cav**2 * 27.1e3 / 8,
200.222e6, 2*np.pi*tau)
# Beam loading by convolution of beam and wake from cavity
inducedVoltageTWC = InducedVoltageTime(beam, profile,
[TWC_impedance_source])
induced_voltage = TotalInducedVoltage(beam, profile,
[inducedVoltageTWC])
induced_voltage.induced_voltage_sum()
V_ind_impSource = np.around(induced_voltage.induced_voltage,
digit_round)
# Beam loading via feed-back system
OTFB_4 = SPSOneTurnFeedback(rf, beam, profile, 4, n_cavities=1)
OTFB_4.counter = 0 # First turn
OTFB_4.omega_c = factor * OTFB_4.TWC.omega_r
# Compute impulse response
OTFB_4.TWC.impulse_response_beam(OTFB_4.omega_c, profile.bin_centers)
# Compute induced voltage in (I,Q) coordinates
OTFB_4.beam_induced_voltage(lpf=False)
# convert back to time
V_ind_OTFB \
= OTFB_4.V_fine_ind_beam.real \
* np.cos(OTFB_4.omega_c*profile.bin_centers) \
+ OTFB_4.V_fine_ind_beam.imag \
* np.sin(OTFB_4.omega_c*profile.bin_centers)
V_ind_OTFB = np.around(V_ind_OTFB, digit_round)
self.assertListEqual(V_ind_impSource.tolist(), V_ind_OTFB.tolist(),
msg="In TravelingWaveCavity test_vind: induced voltages differ")
if VIND_BEAM == True:
profile = Profile(beam, CutOptions=CutOptions(cut_left=-1.e-9,
cut_right=6.e-9, n_slices=140))
profile.track()
# One-turn feedback around 3-, 4-, and 5-section cavities
omega_c = 2*np.pi*f_rf
OTFB_3 = SPSOneTurnFeedback(rf, beam, profile, 3,
Commissioning=CavityFeedbackCommissioning(open_FF=True))
OTFB_4 = SPSOneTurnFeedback(rf, beam, profile, 4,
Commissioning=CavityFeedbackCommissioning(open_FF=True))
OTFB_5 = SPSOneTurnFeedback(rf, beam, profile, 5,
Commissioning=CavityFeedbackCommissioning(open_FF=True))
OTFB_3.counter = 0 # First turn
OTFB_4.counter = 0 # First turn
OTFB_5.counter = 0 # First turn
OTFB_3.omega_c = omega_c
OTFB_4.omega_c = omega_c
OTFB_5.omega_c = omega_c
OTFB_3.TWC.impulse_response_beam(omega_c, profile.bin_centers)
OTFB_4.TWC.impulse_response_beam(omega_c, profile.bin_centers)
OTFB_5.TWC.impulse_response_beam(omega_c, profile.bin_centers)
OTFB_3.beam_induced_voltage(lpf=False)
OTFB_4.beam_induced_voltage(lpf=False)
OTFB_5.beam_induced_voltage(lpf=False)
V_ind_beam = OTFB_3.V_fine_ind_beam +OTFB_4.V_fine_ind_beam + OTFB_5.V_fine_ind_beam
plt.figure()
convtime = np.linspace(-1e-9, -1e-9+len(V_ind_beam.real)*
profile.bin_size, len(V_ind_beam.real))