damaris-script-library/Scripts/Saturation_Recovery/satrec_exp.py

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2015-06-26 12:17:24 +00:00
# -*- coding: iso-8859-1 -*-
TXEnableDelay = 2e-6
TXEnableValue = 0b0001 # TTL line blanking RF amplifier (bit 0)
TXPulseValue = 0b0010 # TTL line triggering RF pulses (bit 1)
ADCSensitivity = 2 # voltage span for ADC
def experiment(): # saturation-recovery experiment
# set up acquisition parameters:
pars = {}
pars['P90'] = 1.7e-6 # 90-degree pulse length (s)
pars['SF'] = 338.7e6 # spectrometer frequency (Hz)
pars['O1'] = -60e3 # offset from SF (Hz)
pars['SW'] = 200e3 # spectral window (Hz)
pars['SI'] = 1*256 # number of acquisition points
pars['NS'] = 8 # number of scans
pars['DS'] = 0 # number of dummy scans
pars['TAU'] = 1 # delay for recovery (s)
pars['DEAD1'] = 5e-6 # receiver dead time (s)
pars['PHA'] = 100 # receiver phase (degree)
# -*- these aren't variable: -*-
pars['NECH'] = 40 # number of saturation pulses
pars['D1'] = 100e-3 # starting interval in saturation sequence (s)
pars['D2'] = 1e-4 # end interval in saturation sequence (s)
pars['DATADIR'] = '/home/fprak/Students/' # data directory
pars['OUTFILE'] = None # output file name
# specify a variable parameter (optional):
pars['VAR_PAR'] = 'TAU' # variable parameter name (a string)
start = 1e-3 # starting value
stop = 5e-0 # end value
steps = 10 # number of values
log_scale = True # log scale flag
stag_range = False # staggered range flag
# check parameters for safety:
if pars['PHA'] < 0:
pars['PHA'] = 360 + pars['PHA']
if pars['P90'] > 20e-6:
raise Exception("Pulse too long!!!")
# check whether a variable parameter is named:
var_key = pars.get('VAR_PAR')
if var_key == 'P90' and (start > 20e-6 or stop > 20e-6):
raise Exception("Pulse too long!!!")
if pars['NS']%4 != 0:
pars['NS'] = int(round(pars['NS'] / 4) + 1) * 4
print 'Number of scans changed to ',pars['NS'],' due to phase cycling'
if pars['D1'] < pars['D2']:
raise Exception("D1 must be greater than D2")
sat_length = sum(log_range(pars['D1'],pars['D2'],pars['NECH']))
if sat_length > 1.:
raise Exception("Saturation sequence too long!!!")
# start the experiment:
if var_key:
# this is an arrayed experiment:
if log_scale:
array = log_range(start,stop,steps)
else:
array = lin_range(start,stop,steps)
if stag_range:
array = staggered_range(array, size = 2)
# estimate the experiment time:
if var_key == 'TAU':
seconds = (sat_length * steps + sum(array)) * (pars['NS'] + pars['DS'])
else:
seconds = (sat_length + pars['TAU']) * steps * (pars['NS']+ pars['DS'])
m, s = divmod(seconds, 60)
h, m = divmod(m, 60)
print '%s%02d:%02d:%02d' % ('Experiment time estimated: ', h, m, s)
# loop for a variable parameter:
for index, pars[var_key] in enumerate(array):
print 'Arrayed experiment for '+var_key+': run = '+str(index+1)+\
' out of '+str(array.size)+': value = '+str(pars[var_key])
# loop for accumulation:
for run in xrange(pars['NS']+pars['DS']):
yield satrec_experiment(pars, run)
synchronize()
else:
# estimate the experiment time:
seconds = (sat_length + pars['TAU']) * (pars['NS'] + pars['DS'])
m, s = divmod(seconds, 60)
h, m = divmod(m, 60)
print '%s%02d:%02d:%02d' % ('Experiment time estimated: ', h, m, s)
# loop for accumulation:
for run in xrange(pars['NS']+pars['DS']):
yield satrec_experiment(pars, run)
# the pulse program:
def satrec_experiment(pars, run):
e=Experiment()
dummy_scans = pars.get('DS')
if dummy_scans:
run -= dummy_scans
pars['PROG'] = 'satrec_experiment'
# phase lists:
pars['PH1'] = [0] # saturation pulses
pars['PH3'] = [0,180,90,270] # measuring pulse
pars['PH2'] = [0,180,90,270] # receiver
# read in variables:
P90 = pars['P90']
SF = pars['SF']
O1 = pars['O1']
DEAD1 = pars['DEAD1']
NECH = pars['NECH']
D1 = pars['D1']
D2 = pars['D2']
TAU = pars['TAU']
PH1 = pars['PH1'][run%len(pars['PH1'])]
PH3 = pars['PH3'][run%len(pars['PH3'])]
PH2 = pars['PH2'][run%len(pars['PH2'])]
PHA = pars['PHA']
# set sampling parameters:
SI = pars['SI']
SW = pars['SW']
while SW <= 10e6 and SI < 256*1024:
SI *= 2
SW *= 2
# set variable delay list for saturation pulses:
vdlist = log_range(D2, D1, NECH-1)
# run the pulse sequence:
# saturation:
e.set_frequency(SF+O1, phase=PH1) # set frequency and phase for saturation pulses
e.ttl_pulse(TXEnableDelay, value=TXEnableValue) # enable RF amplifier
e.ttl_pulse(P90, value=TXEnableValue|TXPulseValue) # apply 90-degree pulse
for delay in vdlist[::-1]:
e.wait(delay-P90-TXEnableDelay) # wait for next pulse
e.ttl_pulse(TXEnableDelay, value=TXEnableValue) # enable RF amplifier
e.ttl_pulse(P90, value=TXEnableValue|TXPulseValue) # apply 90-degree pulse
# recovery:
e.wait(TAU) # recovery time
e.set_phase(PH3) # set phase for measuring pulse
# detection:
e.ttl_pulse(TXEnableDelay, value=TXEnableValue) # enable RF amplifier
e.ttl_pulse(P90, value=TXEnableValue|TXPulseValue) # apply 90-degree pulse
e.set_phase(PHA) # set phase for receiver
e.wait(DEAD1) # wait for coil ringdown
e.record(SI, SW, sensitivity=ADCSensitivity) # acquire signal
# write experiment parameters:
for key in pars.keys():
e.set_description(key, pars[key]) # acquisition parameters
e.set_description('run', run) # current scan
e.set_description('rec_phase', -PH2) # current receiver phase
return e