# na-shifted-echo-antiecho-selective-phase-filtering-p3.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 third-pulse duration
# in three-pulse shifted-echo-antiecho phase-modulated 3Q-MAS sequence,
# the first-pulse duration p1 = 4 micro seconds
# the second-pulse duration p2 = 4 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 p1      4 
  variable p2      4 
}

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

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

  acq -y        
  pulse  $par(p1) $par(rf) x
  filter 1
  pulse  $par(p2) $par(rf) x
  filter 2

  for {set i 1} {$i < $par(np)} {incr i} {
    pulse $par(tsw) $par(rf3) x 
    acq -y
  }
}

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
# -0.00186359193 9.39152491e-18
# -0.00747377785 9.07425148e-18
# -0.0168139021 1.87118822e-17
# -0.0298001149 2.5039815e-17
# -0.0462783393 2.82335631e-17
# -0.066032408 2.93698045e-17
# -0.0888052564 3.97982121e-17
# -0.114329323 5.80884409e-17
# -0.142358454 5.06500636e-17
# -0.172693118 5.25679309e-17
# -0.205193344 5.87392666e-17
# -0.239778013 6.21299773e-17
# -0.276413036 6.68782405e-17
# -0.31509326 7.19052987e-17
# -0.355823255 8.08261393e-17
# -0.398600915 9.55709383e-17
# END