damaris-script-library/Scripts/Hahn_Echo/op_hahn_exp.py
Markus Rosenstihl d994875c0f initial check-in
2015-06-26 12:17:24 +00:00

147 lines
5.3 KiB
Python

# -*- 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(): # solid echo (quadrupolar echo) 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['RD'] = 3 # delay between scans (s)
pars['TAU'] = 13e-6 # echo delay (s)
pars['D4'] = 2e-6 # echo pre-acquisition delay (s)
pars['PHA'] = 0 # receiver phase (degree)
pars['DATADIR'] = '/home/fprak/Students/' # data directory
pars['OUTFILE'] = None # output file name
# specify a variable parameter (optional):
pars['VAR_PAR'] = None # variable parameter name (a string)
start = 20e-6 # starting value
stop = 100e-6 # end value
steps = 12 # number of values
log_scale = False # 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']%8 != 0:
pars['NS'] = int(round(pars['NS'] / 8) + 1) * 8
print 'Number of scans changed to ',pars['NS'],' due to phase cycling'
# 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 = (sum(array)*2 + pars['RD'] * steps) * (pars['NS'] + pars['DS'])
elif var_key == 'RD':
seconds = (sum(array) + pars['TAU']*2 * steps) * (pars['NS'] + pars['DS'])
else:
seconds = (pars['TAU']*2 + pars['RD']) * 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 hahn_experiment(pars, run)
synchronize()
else:
# estimate the experiment time:
seconds = (pars['TAU']*2 + pars['RD']) * (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 hahn_experiment(pars, run)
# the pulse program:
def hahn_experiment(pars, run):
e=Experiment()
dummy_scans = pars.get('DS')
if dummy_scans:
run -= dummy_scans
pars['PROG'] = 'hahn_experiment'
# phase lists [from Tecmag's pulse sequence]:
pars['PH1'] = [ 0, 180, 0, 180, 90, 270, 90, 270] # 90-degree pulse
pars['PH3'] = [ 0, 0, 180, 180, 270, 270, 90, 90] # 180-degree pulse
pars['PH2'] = [ 0, 180, 0, 180, 90, 270, 90, 270] # receiver
# read in variables:
P90 = pars['P90']
P180 = pars['P90']*2
SF = pars['SF']
O1 = pars['O1']
RD = pars['RD']
TAU = pars['TAU']
D4 = pars['D4']
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
# run the pulse sequence:
e.wait(RD) # delay between scans
e.set_frequency(SF+O1, phase=PH1) # set frequency and phase for 1st RF pulse
e.ttl_pulse(TXEnableDelay, value=TXEnableValue) # enable RF amplifier
e.ttl_pulse(P90, value=TXEnableValue|TXPulseValue) # apply 1st 90-degree pulse
e.wait(TAU-P90/2-TXEnableDelay) # wait for TAU
e.set_phase(PH3) # set phase for 2nd 90-degree pulse
e.ttl_pulse(TXEnableDelay, value=TXEnableValue) # enalble RF amplifier
e.ttl_pulse(P180, value=TXEnableValue|TXPulseValue) # apply 2nd 90-degree pulse
e.set_phase(PHA) # set phase for receiver
e.wait(TAU-P180/2+D4) # wait for TAU
e.record(SI, SW, sensitivity=ADCSensitivity) # acquire echo points
# write the experiment parameters:
for key in pars.keys():
e.set_description(key, pars[key]) # pulse sequence parameters
e.set_description('run', run) # current scan
e.set_description('rec_phase', -PH2) # current receiver phase
return e