# na-shifted-echo-antiecho-selective-phase-filtering-p1.in

# approach: filtering the desired coherence (3Q) after the first pulse
#           and (1Q and -3Q) after the second pulse

# spin-3/2 echo amplitude optimization
# versus the first-pulse duration
# in three-pulse shifted-echo phase-modulated 3Q-MAS sequence,
# the second-pulse duration p2 = 4 micro seconds
# the third-pulse duration p3 = 2 micro seconds

spinsys {
  channels 23Na
  nuclei   23Na
  quadrupole 1 1 1e6 1 0 0 0
}

par {
  spin_rate        5000
  variable tsw     0.25
  sw               1.0e6/tsw
  np               17
  crystal_file     rep100
  gamma_angles     10
  proton_frequency 800e6
  start_operator   48*I1z
  detect_operator  I1c
  verbose          1101
  variable rf      90000
  variable rf3     9300
  variable p2      4 
  variable p3      2 
}

proc pulseq {} {
  global par
  maxdt $par(tsw)

  matrix set 1 coherence {3}
  matrix set 2 coherence {1 -3}

  acq -y        
  for {set i 1} {$i < $par(np)} {incr i} {
    pulse $par(tsw) $par(rf) x
    store 2
    filter 1
    pulse $par(p2)  $par(rf) x
    filter 2
    pulse $par(p3) $par(rf3) x
    acq -y
    reset
    prop 2
  }
}

proc main {} {
  global par

  fsave [fsimpson] $par(name).fid
  puts "Larmor frequency (Hz) of 23Na: "
  puts [resfreq 23Na $par(proton_frequency)]
}

# SIMP
# NP=17
# SW=4000000
# TYPE=FID
# DATA
# 0 0
# -1.13105631e-06 -1.94096204e-19
# -3.46393552e-05 1.63702728e-19
# -0.000243838758 -2.31126888e-19
# -0.000925531914 -1.4925491e-19
# -0.0024821646 1.76414618e-19
# -0.00532264084 7.32424164e-19
# -0.00977712823 -1.14371951e-18
# -0.0160641831 5.90419843e-19
# -0.0242950345 1.0719374e-18
# -0.0344680117 3.95840348e-18
# -0.0464243718 3.81891055e-18
# -0.0597893992 3.58323741e-18
# -0.0739621965 6.04247647e-18
# -0.088204724 8.99532073e-18
# -0.101818323 4.40888942e-18
# -0.114329323 2.89688371e-17
# END